Cássio Gabriel [Fri, 5 Jun 2026 04:14:40 +0000 (01:14 -0300)]
ALSA: usb-audio: qcom: Initialize offload control return value
snd_usb_offload_create_ctl() returns ret after walking the USB PCM list,
but ret is only assigned after a playback stream passes the endpoint and
PCM-index filters.
If all playback streams are skipped, for example because there is no
playback endpoint or because all PCM indexes exceed the 0xff control
range, the function returns an uninitialized stack value.
Initialize ret to 0 so the no-control-created path returns deterministic
success, while preserving the existing negative error return when
snd_ctl_add() fails.
netfilter: cttimeout: detach dataplane timeout policy and repurpose refcount
Add a refcount for struct nf_ct_timeout which is used by ct extension to
set the custom ct timeout policy, this tells us that the ct timeout is
being used by a conntrack entry. When the last conntrack entry drops the
refcount on the ct timeout, the ct timeout is released.
Remove the refcount for control plane which controls if the ruleset
refers to the timeout policy. After this update, it is possible to
remove the ct timeout policy from nfnetlink_cttimeout immediately.
This is for simplicity not to handle two refcounts on a single object.
Remove nf_queue_nf_hook_drop(): a packet sitting in nfqueue will just
hold a reference to the nf_ct_timeout object until packet is reinjected,
since this is part of the ct extension, this will be released by the
time the conntrack is freed.
nf_ct_untimeout() is still called to clean up in a best effort basis:
the ct timeout on existing entries gets removed when the ct timeout goes
away, but as long as the iptables ruleset still refers to the ct timeout
through a template, new conntracks may keep attaching it and extend its
lifetime until the rule is removed.
nf_ct_untimeout() is not called anymore from module removal path, this
is unlikely to find timeouts give module refcount is bumped, and the new
refcount already tracks the ct timeout policy use so it is released when
unused.
Fixes: 50978462300f ("netfilter: add cttimeout infrastructure for fine timeout tuning") Fixes: 7e0b2b57f01d ("netfilter: nft_ct: add ct timeout support") Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
netfilter: synproxy: protect nf_ct_seqadj_init() with conntrack lock
nf_ct_seqadj_init() is called without holding the ct lock. This can race
with nf_ct_seq_adjust() when a connection is in CLOSE state due to an
RST or connection reopening. In addition for SYN_RECV state, concurrent
processing of packets can trigger nf_ct_seq_adjust() too. These
situations create a read/write data race.
As synproxy is the only user of nf_ct_seqadj_init() at the moment, fix
this by holding ct->lock inside nf_ct_seqadj_init() until all is done.
Fixes: 48b1de4c110a ("netfilter: add SYNPROXY core/target") Signed-off-by: Fernando Fernandez Mancera <fmancera@suse.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
netfilter: synproxy: fix unaligned memory access in timestamp adjustment
Use get_unaligned_be32() and put_unaligned_be32() to safely read and
write the timestamp fields. This prevents performance degradation due to
unaligned memory access or even a crash on strict alignment
architectures.
This follows the implementation of timestamp parsing in the networking
stack at tcp_parse_options() and synproxy_parse_options().
Fixes: 48b1de4c110a ("netfilter: add SYNPROXY core/target") Signed-off-by: Fernando Fernandez Mancera <fmancera@suse.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
RFC 9293 does not mention anything about duplicated options and each
networking stack handles it in their own way. Currently, Linux kernel is
processing options sequentially and in case of duplicated timestamp
options, the value from the latest one overrides the others.
As SYNPROXY is modifying only the first timestamp option found, a packet
can reach the backend server and it might parse the wrong timestamp
value. Let's just continue parsing the following options and in case a
duplicated timestamp is found, adjust it too.
Fixes: 48b1de4c110a ("netfilter: add SYNPROXY core/target") Signed-off-by: Fernando Fernandez Mancera <fmancera@suse.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
netfilter: synproxy: drop packets if timestamp adjustment fails
If a packet was malformed or if skb_ensure_writable() failed, the
synproxy_tstamp_adjust() function returned 0 indicating an error but it
was ignored on the callers.
Make the function return a boolean instead to clarify the result and
drop the packet if synproxy_tstamp_adjust() failed due to ENOMEM from
skb_ensure_writable(). In addition, if there are malformed options, skip
the tstamp update but do not drop the packet as that should be done by
the policy directly.
Fixes: 48b1de4c110a ("netfilter: add SYNPROXY core/target") Signed-off-by: Fernando Fernandez Mancera <fmancera@suse.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
netfilter: nfnetlink_cthelper: use {READ,WRITE}_ONCE for accessing helper flags
Conntrack helper flags are accessed from packet and netlink dump path.
Concurrent update of userspace helper flags is not possible, because the
nfnl_mutex in held on updates. These flags are only used by userspace
helpers. Use {READ,WRITE}_ONCE() to access this flags from lockless
paths.
netfilter: nfnetlink_osf: fix mss parsing on big-endian architectures
The MSS calculation in nf_osf_match_one() manually shifts bytes to
construct a 16-bit value before passing it to ntohs().
This works on little-endian hosts but it does not work on big-endian as
the bytes are being always shifted and set in the same way for all
architectures.
Use get_unaligned_be16() to fix this on big-endian systems. It also
simplifies the code.
Fixes: 11eeef41d5f6 ("netfilter: passive OS fingerprint xtables match") Signed-off-by: Fernando Fernandez Mancera <fmancera@suse.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Julian Anastasov [Mon, 25 May 2026 03:54:39 +0000 (06:54 +0300)]
ipvs: add conn_max sysctl to limit connections
Currently, we are using atomic_t to track the number of
connections. On 64-bit setups with large memory there is
a risk this counter to overflow. Also, setups with many
containers may need to tune the limit for connections.
Add sysctl control to limit the number of connections to
1,073,741,824 (64-bit) and 16,777,216 (32-bit).
Depending on the admin's privilege, the value is
used to change a soft or hard limit allowing
unprivileged admins to change the soft limit in
range determined by privileged admins.
Tristan Madani [Tue, 2 Jun 2026 17:16:41 +0000 (17:16 +0000)]
xfrm: iptfs: fix ABBA deadlock in iptfs_destroy_state()
iptfs_destroy_state() calls hrtimer_cancel() while holding a spinlock
that the timer callback also acquires, leading to an ABBA deadlock on
SMP systems.
For the output timer (iptfs_timer):
- iptfs_destroy_state() holds x->lock, calls hrtimer_cancel()
- iptfs_delay_timer() callback takes x->lock
For the drop timer (drop_timer):
- iptfs_destroy_state() holds drop_lock, calls hrtimer_cancel()
- iptfs_drop_timer() callback takes drop_lock
Both timers use HRTIMER_MODE_REL_SOFT, so their callbacks run in softirq
context. When hrtimer_cancel() is called for a soft timer that is
currently executing on another CPU, hrtimer_cancel_wait_running() spins
on softirq_expiry_lock -- the same lock held by the softirq running the
callback. If the callback is blocked waiting for the spinlock held by
the caller of hrtimer_cancel(), a circular dependency forms:
CPU 0: holds lock_A -> waits for softirq_expiry_lock
CPU 1: holds softirq_expiry_lock -> waits for lock_A
Fix by calling hrtimer_cancel() before acquiring the respective locks.
hrtimer_cancel() is safe to call without holding any lock and will wait
for any in-progress callback to complete. For the output timer, the
lock is still acquired afterwards to drain the packet queue. For the
drop timer, the lock/unlock pair is removed entirely since it only
existed to serialize with the timer callback, which hrtimer_cancel()
already guarantees.
__arch_counter_get_cntpct() and __arch_counter_get_cntvct() open-code
the same ECV-aware ALTERNATIVE block that arch_timer_read_cntpct_el0()
and arch_timer_read_cntvct_el0() already provide in the same header.
The two pairs are byte-for-byte identical except for the trailing
arch_counter_enforce_ordering() the __arch_counter_get_* variants add.
Replace the duplicated inline assembly in __arch_counter_get_cntpct()
and __arch_counter_get_cntvct() with calls to the corresponding helpers.
This mirrors commit 00b39d150986 ("arm64: vdso: Use
__arch_counter_get_cntvct()"), which removed similar duplication from
the vDSO, and keeps the system-counter read sequence in a single place,
reducing assembly code in the kernell
No functional change: the resulting inline assembly, alternatives, and
clobbers are unchanged; only the source-level expression of the read
moves into the existing helper.
Verified by rebuilding the consumers of these helpers before and after
the change and comparing the resulting disassembly:
- arch/arm64/kernel/vdso/vdso.so (final linked vDSO):
bit-identical (same sha256 across rebuilds)
- arch/arm64/kernel/vdso/vgettimeofday.o: identical disassembly
- arch/arm64/lib/delay.o: identical disassembly
- drivers/clocksource/arm_arch_timer.o: same 50 functions with
byte-identical instruction streams; only difference is function
ordering inside .text and NOP padding, with no opcodes added or
removed.
Signed-off-by: Breno Leitao <leitao@debian.org> Signed-off-by: Will Deacon <will@kernel.org>
kvm->arch.nested_mmus[] is walked under kvm->mmu_lock, including from the
MMU notifier path (kvm_unmap_gfn_range() -> kvm_nested_s2_unmap()), which
can run at any time. kvm_vcpu_init_nested() reallocates the array and frees
the old buffer while holding only kvm->arch.config_lock, so such a walker
can reference the freed array.
Allocate the new array outside of mmu_lock, as the allocation can sleep.
Under the lock, copy the existing entries, fix up the back pointers and
reassign the array. Free the old buffer after dropping the lock, as
kvfree() can sleep as well.
Fixes: 4f128f8e1aaac ("KVM: arm64: nv: Support multiple nested Stage-2 mmu structures") Signed-off-by: Hyunwoo Kim <imv4bel@gmail.com> Reviewed-by: Oliver Upton <oupton@kernel.org> Link: https://patch.msgid.link/aiKIVVeIr1aAB1yp@v4bel Signed-off-by: Marc Zyngier <maz@kernel.org> Cc: stable@vger,kernel.org
Joey Gouly [Thu, 4 Jun 2026 10:54:34 +0000 (11:54 +0100)]
KVM: arm64: Restore POR_EL0 access to host EL0
CPTR_EL2.E0POE was being cleared in __deactivate_cptr_traps_vhe(), which meant
that any accesses to POR_EL0 from host EL0 would trap and be reported to
userspace as an Illegal instruction. This would happen after running any VM,
regardless if it used POE or not.
ptdesc_t sounds very similar to the core MM struct ptdesc which is actually
the memory descriptor for page table allocations. Hence rename this typedef
element as ptval_t instead for better clarity and separation.
Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will@kernel.org> Cc: David Hildenbrand <david@kernel.org> Cc: Mike Rapoport <rppt@kernel.org> Cc: linux-efi@vger.kernel.org Cc: linux-kernel@vger.kernel.org Cc: linux-arm-kernel@lists.infradead.org Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Acked-by: David Hildenbrand (Arm) <david@kernel.org> Suggested-by: David Hildenbrand (Arm) <david@kernel.org> Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com> Signed-off-by: Will Deacon <will@kernel.org>
Ard Biesheuvel [Thu, 4 Jun 2026 15:11:57 +0000 (17:11 +0200)]
arm64: mm: Defer remap of linear alias of data/bss
Marking the linear alias of data/bss invalid involves calling
set_memory_valid(), which calls split_kernel_leaf_mapping() under the
hood.
On BBML2_NOABORT capable systems, this may result in the need to
allocate page tables at a time when the generic memory allocation APIs
are not yet available, resulting in a splat like
Ard Biesheuvel [Thu, 4 Jun 2026 15:11:56 +0000 (17:11 +0200)]
KVM: arm64: Omit tag sync on stage-2 mappings of the zero page
Commit
f620d66af316 ("arm64: mte: Do not flag the zero page as PG_mte_tagged")
removed the PG_mte_tagged flag from the zero page, but missed a KVM code
path that may set this flag on the zero page when it is used in a
stage-2 CoW mapping of anonymous memory.
So disregard the zero page explicitly in sanitise_mte_tags().
Fixes: f620d66af316 ("arm64: mte: Do not flag the zero page as PG_mte_tagged") Cc: stable@vger.kernel.org # 5.10.x Suggested-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Will Deacon <will@kernel.org>
Ard Biesheuvel [Thu, 4 Jun 2026 15:11:55 +0000 (17:11 +0200)]
arm64: Avoid double evaluation of __ptep_get()
Sashiko warns that the new pte_valid_noncont() macro is used in a manner
where the argument (which performs a READ_ONCE() of the descriptor) is
evaluated twice.
Drop the macro that we just added, and move the check into the newly
added users.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Will Deacon <will@kernel.org>
Ard Biesheuvel [Thu, 4 Jun 2026 15:11:53 +0000 (17:11 +0200)]
arm64: Rename page table BSS section to .bss..pgtbl
Rename the .pgdir.bss section to .bss..pgtbl so that the compiler will
notice the leading ".bss" and mark it as NOBITS by default (rather than
PROGBITS, which would take up space in Image binary, forcing all of the
preceding BSS to be emitted into the image as well). This supersedes the
NOLOAD linker directive, which achieves the same thing, and can be
therefore be dropped.
Also, rename .pgdir to .pgtbl to be more generic, as page tables of
various levels will reside here.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Tested-by: Mark Brown <broonie@kernel.org> Signed-off-by: Will Deacon <will@kernel.org>
Removing the try_vesa_interface gate caused a backlight regression on
panels whose VBT correctly reports INTEL_BACKLIGHT_DISPLAY_DDI and whose
PWM path is the actual backlight control, but whose DPCD optimistically
advertises DP_EDP_BACKLIGHT_AUX_ENABLE_CAP / _BRIGHTNESS_AUX_SET_CAP.
After the commit such panels silently bind to the VESA AUX backlight
funcs; AUX writes complete but the panel ignores them, leaving
brightness stuck (no-op backlight). Observed on at least KBL and TGL
eDP setups.
HyeongJun An [Thu, 4 Jun 2026 15:00:52 +0000 (00:00 +0900)]
x86/process: Convert rdmsr() to rdmsrq() in arch_post_acpi_subsys_init() to address W=1 warning
arch_post_acpi_subsys_init() reads MSR_K8_INT_PENDING_MSG with rdmsr()
into a lo/hi pair but only uses the low 32 bits: K8_INTP_C1E_ACTIVE_MASK
(0x18000000) lies entirely within them. The 'hi' half is never consumed,
which triggers a -Wunused-but-set-variable warning under W=1:
arch/x86/kernel/process.c: In function 'arch_post_acpi_subsys_init':
arch/x86/kernel/process.c:972:17: warning: variable 'hi' set but not used
Read the full MSR into a single u64 with rdmsrq() and test the mask
against it, dropping the now-unnecessary lo/hi variables.
Claudiu Beznea [Wed, 3 Jun 2026 15:16:37 +0000 (18:16 +0300)]
pinctrl: renesas: rzg2l: Use raw_spinlock_irqsave() on power source update
The rest of the driver uses raw_spin_lock_irqsave() and
raw_spin_unlock_irqrestore() for locking. To avoid concurrency issues
or deadlocks, use raw_spinlock_irqsave() via the scoped_guard() helper
for power source updates as well.
Fixes: bbe2277dedbe ("pinctrl: renesas: rzg2l: Add support for selecting power source for {WDT,AWO,ISO}") Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> Link: https://patch.msgid.link/20260603151642.4075678-2-claudiu.beznea@kernel.org Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Hyunwoo Kim [Wed, 3 Jun 2026 12:09:33 +0000 (21:09 +0900)]
KVM: arm64: Take the SRCU lock for page table walks in fault injection and AT emulation
walk_s1() and kvm_walk_nested_s2() expect to be called while holding
kvm->srcu to guard against memslot changes. While this is generally
the case, __kvm_at_s12() and __kvm_find_s1_desc_level() call into the
respective walkers without taking kvm->srcu.
Fix by acquiring kvm->srcu prior to the table walk in both instances.
Cc: stable@vger.kernel.org Fixes: 50f77dc87f13 ("KVM: arm64: Populate level on S1PTW SEA injection") Fixes: be04cebf3e78 ("KVM: arm64: nv: Add emulation of AT S12E{0,1}{R,W}") Suggested-by: Oliver Upton <oupton@kernel.org> Signed-off-by: Hyunwoo Kim <imv4bel@gmail.com> Reviewed-by: Oliver Upton <oupton@kernel.org> Link: https://patch.msgid.link/aiAZfdeyanIvP8SD@v4bel Signed-off-by: Marc Zyngier <maz@kernel.org>
Hyunwoo Kim [Mon, 1 Jun 2026 14:53:26 +0000 (23:53 +0900)]
KVM: arm64: vgic-its: Drop the translation cache reference only for the erased entry
vgic_its_invalidate_cache() walks the per-ITS translation cache with
xa_for_each() and drops the cache's reference on each entry with
vgic_put_irq(). It puts the iterated pointer, though, rather than the
value returned by xa_erase().
The function is called from contexts that do not exclude one another: the
ITS command handlers hold its_lock, the GITS_CTLR write path holds
cmd_lock, and the path that clears EnableLPIs in a redistributor's
GICR_CTLR holds neither. Two or more of them can drain the same cache
concurrently, and if each one observes the same entry, erases it and then
puts it, the single reference the cache holds on that entry is dropped
more than once. The entry can then be freed while an ITE still maps it.
xa_erase() is atomic and returns the previous entry, so put only the entry
that this context actually removed. The cache reference is then dropped
exactly once per entry even when the invalidations run concurrently, and
the behavior is unchanged when only one context runs.
Fixes: 8201d1028caa ("KVM: arm64: vgic-its: Maintain a translation cache per ITS") Signed-off-by: Hyunwoo Kim <imv4bel@gmail.com> Reviewed-by: Oliver Upton <oupton@kernel.org> Link: https://patch.msgid.link/ah2c5lu4JbUg7dj-@v4bel Signed-off-by: Marc Zyngier <maz@kernel.org> Cc: stable@vger.kernel.org
The Realtek interrupt driver currently supports only single core
systems. So the higher end devices like RTL839x and RTL930x with
dual VPEs must be driven with NR_CPU=1. Enhance the driver to
support multicore (dual VPE) systems. For this:
- Extend the register map for multiple cores
- Search for multiple CPU cores in the devicetree
- Improve the register helpers to support multiple cores
- Add an affinity setter
- Enhance the IRQ handler for multiple cores
The usage of these registers is very inconsistent. GIMR is addressed
directly while IRR has a helper that needs a macro as an input. Harmonize
this by providing consistent helpers that improve code readability.
The callers of these helpers use classic lock/unlock functions and
sometimes use the wrong locking helper. E.g. irqsave variants are used in
mask/unmask although not needed. Adapt and fix the surrounding call
locations.
Tony Luck [Fri, 5 Jun 2026 04:46:49 +0000 (21:46 -0700)]
x86/resctrl: Only check Intel systems for SNC
topology_num_nodes_per_package() reports values greater than one on certain
AMD systems resulting in resctrl's Intel model specific SNC detection
printing the confusing message:
"CoD enabled system? Resctrl not supported"
Add a check for Intel systems before looking at the topology.
Namjae Jeon [Mon, 18 May 2026 11:46:55 +0000 (20:46 +0900)]
iomap: introduce IOMAP_F_ZERO_TAIL flag
In filesystems that maintain a separate Valid Data Length, such as exFAT
and NTFS, a partial write may start at or beyond the current valid_size and
extend it. In this case, the region after the previous valid_size but
within the same filesystem block is considered unwritten.
This patch introduces IOMAP_F_ZERO_TAIL. When this flag is set in iomap,
__iomap_write_begin() will zero only the tail portion while preserving any
valid data before it in the same block.
Without this tail zeroing, stale data in the unwritten portion of the block
can remain in the page cache. Subsequent reads can then return incorrect
contents from that region.
Acked-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Namjae Jeon <linkinjeon@kernel.org> Link: https://patch.msgid.link/20260518114705.9601-2-linkinjeon@kernel.org Acked-by: "Darrick J. Wong" <djwong@kernel.org> Reviewed-by: "Darrick J. Wong" <djwong@kernel.org> Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
Gary Guo [Tue, 2 Jun 2026 14:17:55 +0000 (15:17 +0100)]
rust: dma: update to keyworded index projection syntax
Demonstrate the preferred syntax of index projection in DMA documentation
and examples. A few `[i]?` cases are converted to demonstrate the new
variant.
Reviewed-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Andreas Hindborg <a.hindborg@kernel.org> Reviewed-by: Alexandre Courbot <acourbot@nvidia.com> Signed-off-by: Gary Guo <gary@garyguo.net> Acked-by: Danilo Krummrich <dakr@kernel.org> Link: https://patch.msgid.link/20260602-projection-syntax-rework-v2-4-6989470f5440@garyguo.net Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Gary Guo [Tue, 2 Jun 2026 14:17:54 +0000 (15:17 +0100)]
rust: ptr: add panicking index projection variant
There have been a few cases where the programmer knows that the indices are
in bounds but the compiler cannot deduce that. This is also
compiler-version-dependent, so using build indexing here can be
problematic. On the other hand, it is also not ideal to use the fallible
variant, as it adds an error handling path that is never hit.
Add a new panicking index projection for this scenario. Like all panicking
operations, this should be used carefully only in cases where the user
knows the index is going to be in bounds, and panicking would indicate
something is catastrophically wrong.
To signify this, require users to explicitly denote the type of index being
used. The existing two types of index projections also gain the keyworded
version, which will be the recommended way going forward.
The keyworded syntax also paves the way of perhaps adding more flavors in
the future, e.g. `unsafe` index projection. However, unless the code is
extremely performance sensitive and bounds checking cannot be tolerated,
the panicking variant is safer and should be preferred, so it will be left
to the future when demand arises.
Signed-off-by: Gary Guo <gary@garyguo.net> Reviewed-by: Alexandre Courbot <acourbot@nvidia.com> Reviewed-by: Andreas Hindborg <a.hindborg@kernel.org> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Acked-by: Danilo Krummrich <dakr@kernel.org> Link: https://patch.msgid.link/20260602-projection-syntax-rework-v2-3-6989470f5440@garyguo.net
[ Fixed broken intra-doc link. Added a few extra intra-doc links. Reworded
some docs slightly. - Miguel ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Gary Guo [Tue, 2 Jun 2026 14:17:52 +0000 (15:17 +0100)]
rust: ptr: rename `ProjectIndex::index` to `build_index`
The corresponding `SliceIndex` trait in Rust uses `index` to mean the
panicking variant, which is also being added to `ProjectIndex`. Hence
rename our custom `build_error!` index variant to `build_index`.
Kyle Zeng [Fri, 5 Jun 2026 08:02:04 +0000 (01:02 -0700)]
ALSA: seq: dummy: fix UMP event stack overread
The dummy sequencer port forwards events by copying an incoming
struct snd_seq_event into a stack temporary, rewriting source and
destination, and dispatching the temporary to subscribers. That legacy
event storage is smaller than struct snd_seq_ump_event.
When a UMP event reaches the dummy client, the copy leaves the UMP flag
set but only provides legacy-sized stack storage. The subscriber
delivery path then uses snd_seq_event_packet_size() and copies a
UMP-sized packet from that stack object, reading past the end of the
temporary.
Use the existing union __snd_seq_event storage and copy the packet size
reported for the incoming event before rewriting the common routing
fields. This preserves the full UMP packet for UMP events while keeping
legacy event handling unchanged.
Merge patch series "proc: protect ptrace_may_access() with exec_update_lock"
Jann Horn <jannh@google.com> says:
My understanding is that procfs is effectively maintained by the VFS
maintainers (though scripts/get_maintainer.pl claims that there are
no maintainers for procfs because the VFS entry only claims files
directly in fs/, and the procfs entry has no maintainers listed on
it).
In procfs, most uses of ptrace_may_access() should use
exec_update_lock to avoid TOCTOU issues with concurrent privileged
execve() (like setuid binary execution).
This series doesn't fix all the remaining issues in procfs, but it fixes
the easy cases for now; I will probably follow up with fixes for the
gnarlier cases later unless someone else wants to do that.
I have checked that procfs files still work with these changes and that
CONFIG_PROVE_LOCKING=y doesn't generate any warnings.
(checkpatch complains about missing argument names in
proc_op::proc_get_link, but that was already the case before my patch.)
* patches from https://patch.msgid.link/20260518-procfs-lockfix-part1-v1-0-5c3d20e0ac33@google.com:
proc: protect ptrace_may_access() with exec_update_lock (FD links)
proc: protect ptrace_may_access() with exec_update_lock (part 1)
Jann Horn [Mon, 18 May 2026 16:35:16 +0000 (18:35 +0200)]
proc: protect ptrace_may_access() with exec_update_lock (FD links)
proc_pid_get_link() and proc_pid_readlink() currently look up the task from
the pid once, then do the ptrace access check on that task, then look up
the task from the pid a second time to do the actual access.
That's racy in several ways.
To fix it, pass the task to the ->proc_get_link() handler, and instead of
proc_fd_access_allowed(), introduce a new helper call_proc_get_link() that
looks up and locks the task, does the access check, and calls
->proc_get_link().
Jann Horn [Mon, 18 May 2026 16:35:15 +0000 (18:35 +0200)]
proc: protect ptrace_may_access() with exec_update_lock (part 1)
Fix the easy cases where procfs currently calls ptrace_may_access() without
exec_update_lock protection, where the fix is to simply add the extra lock
or use mm_access():
- do_task_stat(): grab exec_update_lock
- proc_pid_wchan(): grab exec_update_lock
- proc_map_files_lookup(): use mm_access() instead of get_task_mm()
- proc_map_files_readdir(): use mm_access() instead of get_task_mm()
- proc_ns_get_link(): grab exec_update_lock
- proc_ns_readlink(): grab exec_update_lock
wifi: nl80211: Increase ie_len size to prevent truncated IEs in new peer notifications
Currently, ie_len in cfg80211_notify_new_peer_candidate is defined as
1-byte field, capping the maximum IE list size at 255 bytes. When a
large beacon is received, the IE list is truncated, passing incomplete
data to wpa_supplicant. This causes supplicant to fail parsing the IEs.
Increasing the size of ie_len to allow the full length of the IE list to
be forwarded properly.
Rosen Penev [Fri, 5 Jun 2026 00:56:27 +0000 (17:56 -0700)]
wifi: mac80211: fold tid_ampdu_rx allocations into a flexible array
Convert the separately-allocated reorder_buf pointer to a C99 flexible
array member at the end of struct tid_ampdu_rx, with both the
sk_buff_head and the jiffies timestamp in each array element. This
collapses three allocations into one and removes the corresponding
kfree() pairs from the error and free paths.
wifi: mac80211: Fix -Wc23-extensions in hwmp_route_info_get()
When building with a version of clang that supports
'-fms-anonymous-structs' (which will be used by the kernel instead of
the wider '-fms-extensions'), there are a couple warnings after some
recent mesg_hwmp.c changes:
net/mac80211/mesh_hwmp.c:373:3: error: label followed by a declaration is a C23 extension [-Werror,-Wc23-extensions]
373 | struct ieee80211_mesh_hwmp_preq_top *preq_elem_top =
| ^
net/mac80211/mesh_hwmp.c:390:3: error: label followed by a declaration is a C23 extension [-Werror,-Wc23-extensions]
390 | struct ieee80211_mesh_hwmp_prep_top *prep_elem_top =
| ^
2 errors generated.
Enclose the switch case blocks in braces to clear up the warning.
Mirela Rabulea [Fri, 22 May 2026 14:31:20 +0000 (17:31 +0300)]
media: v4l2-fwnode: Fix subdev owner overwritten in v4l2_async_register_subdev_sensor()
The v4l2 helper v4l2_async_register_subdev_sensor() calls
v4l2_async_register_subdev(), which is a macro that expands to
__v4l2_async_register_subdev(sd,THIS_MODULE). Since the macro is expanded
inside v4l2-fwnode.c, THIS_MODULE resolves to the v4l2-fwnode module
rather than the sensor driver module that originally set sd->owner. When
v4l2-fwnode is built-in, THIS_MODULE evaluates to NULL, which then
overwrites the sensor driver's owner with NULL.
This causes the problem that the sensor module's reference count is never
incremented during async registration, so the module can be removed while
the subdevice is still in use by a notifier (e.g., a CSI-2 receiver
bridge driver).
Fix this by renaming v4l2_async_register_subdev_sensor() to
__v4l2_async_register_subdev_sensor() with an added explicit module
argument and introducing a wrapper macro:
#define v4l2_async_register_subdev_sensor(sd) \
__v4l2_async_register_subdev_sensor(sd, THIS_MODULE)
This ensures the sensor driver module is properly referenced even when
the sensor driver does not init the owner field before calling
v4l2_async_register_subdev_sensor() and prevents premature module removal.
Fixes: aef69d54755d ("media: v4l: fwnode: Add a convenience function for registering sensors") Cc: stable@vger.kernel.org Suggested-by: Frank Li <Frank.Li@nxp.com> Link: https://lore.kernel.org/linux-media/20240315073125.275501-2-sakari.ailus@linux.intel.com/ Signed-off-by: Mirela Rabulea <mirela.rabulea@nxp.com> Reviewed-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com> Reviewed-by: Frank Li <Frank.Li@nxp.com> Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Sven Eckelmann [Thu, 4 Jun 2026 19:35:52 +0000 (21:35 +0200)]
batman-adv: fix kernel-doc typos and grammar errors
Various minor errors were gathered over the time in batman-adv's kernel-doc
comments. Get rid of many of them before they are copied (again) to new
functions.
Signed-off-by: Sven Eckelmann <sven@narfation.org>
All receive handlers in batman-adv are consuming the skbuff independent of
the result of the handler. The "(without freeing the skb) on failure" is
therefore not corrrect anymore for the current implementation.
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Sven Eckelmann [Thu, 4 Jun 2026 19:58:31 +0000 (21:58 +0200)]
batman-adv: uapi: keep kernel-doc in struct member order
The order of the members of struct batadv_coded_packet and struct
batadv_unicast_tvlv_packet didn't match the kernel doc. This is the case
for all other structures and should also be done the same way for these
two.
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Sven Eckelmann [Thu, 4 Jun 2026 19:35:04 +0000 (21:35 +0200)]
batman-adv: bla: update stale kernel-doc
The bridge-loop-avoidance code was changed recently to avoid inconsistent
state and race condition problems. The kernel-doc addded in these commits
(and related code) has various minor deficits which are now resolved.
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Sven Eckelmann [Thu, 4 Jun 2026 09:09:04 +0000 (11:09 +0200)]
batman-adv: tp_meter: update stale kernel-doc after refactoring
The tp_meter codebase was recently refactored:
* throughput meter sender and receiver variables were split into
two different structures
* the congestion control variables were extracted in a separate structure
But the kernel-doc was not updated everywhere to reflect these changes.
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Sven Eckelmann [Wed, 3 Jun 2026 08:47:53 +0000 (10:47 +0200)]
batman-adv: document cleanup of batadv_wifi_net_devices entries
It doesn't seem to be obvious how the entries from the
batadv_wifi_net_devices rhashtable are getting removed before the actual
rhashtable is destroyed. Document the idea behind the process and which
steps are involved.
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Sven Eckelmann [Tue, 2 Jun 2026 15:46:10 +0000 (17:46 +0200)]
batman-adv: use GFP_KERNEL allocations for the wifi detection cache
The batadv_wifi_net_device_insert() is called with ASSERT_RTNL() held, but
not inside a spinlock or another context which prevents "might_sleep"
functions. To relax the requirements for the allocator, use GFP_KERNEL.
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Sven Eckelmann [Tue, 2 Jun 2026 15:41:15 +0000 (17:41 +0200)]
batman-adv: drop duplicated wifi_flags assignments
During the initialization of the batadv_wifi_net_device_state, it is enough
to write the wifi_flags once before the batadv_wifi_net_device_state is
added to the batadv_wifi_net_devices rhashtable.
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Sven Eckelmann [Tue, 26 May 2026 07:09:32 +0000 (09:09 +0200)]
batman-adv: convert cancellation of work items to disable helper
With commit 86898fa6b8cd ("workqueue: Implement disable/enable for
(delayed) work items"), work queues gained the ability to permanently
disallow re-queuing of work items. This is particularly important during
object teardown, where a work item must not be re-armed after shutdown
begins.
Convert all cancel_work_sync() and cancel_delayed_work_sync() call sites to
their disable_* equivalents to clarify the intent to prevent re-arming
after teardown.
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Sven Eckelmann [Thu, 4 Jun 2026 08:58:51 +0000 (10:58 +0200)]
batman-adv: tp_meter: initialize last_recv_time during init
The last_recv_time is the most important indicator for a receiver session
to figure out whether a session timed out or not. But this information was
only initialized after the session was added to the tp_receiver_list and
after the timer was started.
In the worst case, the timer (function) could have tried to access this
information before the actual initialization was reached. Like rest of the
variables of the tp_meter receiver session, this field has to be filled out
before any other (parallel running) context has the chance to access it.
Cc: stable@kernel.org Fixes: 33a3bb4a3345 ("batman-adv: throughput meter implementation") Signed-off-by: Sven Eckelmann <sven@narfation.org>
Al Viro [Tue, 5 May 2026 04:20:19 +0000 (00:20 -0400)]
make cursors NORCU
All it requires is making sure that d_walk() will skip *all*
CURSOR dentries, even if somebody passes it one as an argument.
Cursors are negative and unhashed all along, never get added to
LRU or to shrink lists and no RCU references via ->d_sib are
possible for those - dentry_unlist() makes sure that no killed
dentry has ->d_sib.next left pointing to a cursor.
Seeing that a cursor is allocated every time we open a directory
on autofs, debugfs, devpts, etc., avoiding an RCU delay when such
opened files get closed is attractive...
Al Viro [Wed, 15 Apr 2026 23:29:53 +0000 (19:29 -0400)]
nfs: get rid of fake root dentries
... just grab the reference to the (real) root we are about to return
for the first mount of this superblock and be done with that.
Once upon a time dentry tree eviction at fs shutdown used to break
if ->s_root had been spliced on top of something; that hadn't been
the case for years now, and these fake root dentries violate a bunch
of invariants. Let's get rid of them...
Al Viro [Sat, 18 Apr 2026 22:39:03 +0000 (18:39 -0400)]
wind ->s_roots via ->d_sib instead of ->d_hash
shrink_dcache_for_umount() is supposed to handle the possibility of
some of the dentries to be evicted being in other threads shrink
lists; it either kills them, leaving an empty husk to be freed by
the owner of shrink list whenever it gets around to that, or it
waits for the eviction in progress to get completed.
That relies upon dentry remaining attached to the tree until the
eviction reaches dentry_unlist() and its ->d_sib gets removed
from the list. Unfortunately, the secondary roots are linked
via ->d_hash, rather than ->d_sib and they become removed from
that list before their inode references are dropped.
If shrink_dentry_list() from another thread ends up evicting
one of the secondary roots and gets to that point in dentry_kill()
when shrink_dcache_for_umount() is looking for secondary roots,
the latter will *not* notice anything, possibly leading to
warnings about busy inodes at umount time and all kinds of breakage
after that.
Moreover, shrink_dcache_for_umount() walks the list of secondary
roots with no protection whatsoever, so it might end up calling
dget() on a dentry that already passed through
lockref_mark_dead(&dentry->d_lockref);
ending up with corrupted refcount and possible UAF.
AFAICS, the most straightforward way to deal with that would be
to have secondary roots linked via ->d_sib rather than ->d_hash;
then they would remain on the list until killed, and we could
use d_add_waiter() machinery to wait for eviction in progress.
Changes:
* secondary roots look the same as ->s_root from d_unhashed()
and d_unlinked() POV now.
* secondary roots are represented as "no parent, but on ->d_sib"
instead of "no parent, but on ->d_hash".
* since ->d_sib is a plain hlist, we protect it with per-superblock
spinlock (sb->s_roots_lock) instead of the LSB of the head pointer (for
non-root dentries it would be protected by ->d_lock of parent).
* __d_obtain_alias() uses ->d_sib for linkage when allocating
a secondary root.
* d_splice_alias_ops() detects splicing of a secondary root and
removes it from the list before calling __d_move().
* dentry_unlist() detects eviction of a secondary root and
removes it from the list; no need to play the games for d_walk() sake,
since the latter is not going to look for the next sibling of those
anyway.
* ___d_drop() doesn't care about ->s_roots anymore.
* shrink_dcache_for_umount() uses proper locking for access to
the list of secondary roots and if it runs into one that is in the middle
of eviction waits for that to finish.
Al Viro [Thu, 23 Apr 2026 18:29:18 +0000 (19:29 +0100)]
shrinking rcu_read_lock() scope in d_alloc_parallel()
The current use of rcu_read_lock() uses in d_alloc_parallel()
is fairly opaque - the single large scope serves two purposes.
We start with lookup in normal hash, and there rcu_read_lock()
scope puts __d_lookup_rcu() and subsequent lockref_get_not_dead() into
the same RCU read-side critical area.
If no match is found, we proceed to lock the hash chain of
in-lookup hash and scan that for a match. If we find a match, we want
to grab it and wait for lookup in progress to finish. Since the bitlock
we use for these hash chains has to nest inside ->d_lock, we need to
unlock the chain first and use lockref_get_not_dead() on the match.
That has to be done without breaking the RCU read-side critical area,
and we use the same rcu_read_lock() scope to bridge over.
The thing is, after having grabbed the reference (and it is
very unlikely to fail) we proceed to grab ->d_lock - d_wait_lookup()
and __d_lookup_unhash()/__d_wake_in_lookup_waiters() are using that for
serialization. That makes lockref_get_not_dead() pointless - trying
to avoid grabbing ->d_lock for refcount increment, only to grab it
anyway immediately after that. If we grab ->d_lock first and replace
lockref_get_not_dead() with direct check for sign and increment if
non-negative we can move rcu_read_unlock() to immediately after grabbing
->d_lock. Moreover, we don't need the RCU read-side critical area to
be contiguous since before earlier __d_lookup_rcu() - we can just as
well terminate the earlier one ASAP and call rcu_read_lock() again only
after having found a match (if any) in the in-lookup hash chain.
That makes the entire thing easier to follow and the purpose
of those rcu_read_lock() calls easier to describe - the first scope is
for __d_lookup_rcu() + lockref_get_not_dead(), the second one bridges
over from the bitlock scope to the ->d_lock scope on the match found in
in-lookup hash.
Al Viro [Tue, 21 Apr 2026 19:52:13 +0000 (15:52 -0400)]
d_walk(): shrink rcu_read_lock() scope
we only need it to bridge over from ->d_lock scope of child to ->d_lock
scope of parent; dropping ->d_lock at rename_retry doesn't need to be
in rcu_read_lock() scope.
Al Viro [Sat, 11 Apr 2026 08:17:02 +0000 (04:17 -0400)]
adjust calling conventions of lock_for_kill(), fold __dentry_kill() into dentry_kill()
Pull dropping ->d_lock on lock_for_kill() failure into lock_for_kill() itself.
That reduces dentry_kill() to
if (!lock_for_kill(dentry))
return NULL;
return __dentry_kill(dentry);
at which point it's easier to move that if (...) into the beginning of __dentry_kill()
itself and rename it into dentry_kill().
Document the new calling conventions of lock_for_kill().
Al Viro [Sat, 11 Apr 2026 08:01:28 +0000 (04:01 -0400)]
Document rcu_read_lock() use in select_collect2()
If select_collect2() finds something that is neither busy nor can
be moved to shrink list, it needs to return that to caller's caller
(shrink_dcache_tree()) ASAP and do so without grabbing references (among
other things, it might be already dying, in which case refcount can't be
incremented). We are called inside a ->d_lock scope, but that scope is
going to be terminated as soon as we return to caller (d_walk()); ->d_lock
will be retaken by shrink_dcache_tree(), but we need to bridge between
these scopes, turning them into contiguous RCU read-side critical area.
We do that with rcu_read_lock() scope - it spans from unbalanced
rcu_read_lock() in select_collect2() to unbalanced rcu_read_unlock()
in shrink_dcache_tree(). That works, but it really needs to be documented;
it's rather unidiomatic and it had caused quite a bit of confusion - some
of it in form of patches "fixing" the damn thing.
Al Viro [Sat, 11 Apr 2026 07:56:42 +0000 (03:56 -0400)]
Shift rcu_read_{,un}lock() inside fast_dput()
Shrink rcu_read_lock() scopes surrounding fast_dput() calls.
Both callers are immediately preceded and followed by
rcu_read_lock()/rcu_read_unlock() resp. Shrink that down
into fast_dput() itself; in case when fast_dput() ends up
grabbing ->d_lock, we can pull rcu_read_unlock() up to
right after spin_lock().
Al Viro [Sat, 11 Apr 2026 07:24:28 +0000 (03:24 -0400)]
simplify safety for lock_for_kill() slowpath
rcu_read_lock() scopes in dentry eviction machinery are too wide
and badly structured; we end up with too many of those, quite
a few essentially identical. Worse, quite a few of the function
involved are not neutral wrt that, making them harder to reason about.
rcu_read_lock() scope is not the only thing establishing an
RCU read-side critical area - spin_lock scope does the same and
they can be mixed - the sequence
rcu_read_lock()
...
spin_lock()
...
rcu_read_unlock()
...
rcu_read_lock()
...
spun_unlock()
...
rcu_read_unlock()
is an unbroken RCU read-side critical area.
Use of that observation allows to simplify things. First of all,
lock_for_kill() relies upon being in an unbroken RCU read-side
critical area. It's always called with ->d_lock held, and normally
returns without having ever dropped that spinlock. We would not
need rcu_read_lock() at all, if not for the slow path - if trylock
of inode->i_lock fails, we need to drop and retake ->d_lock.
Having all calls of lock_for_kill() inside an rcu_read_lock() scope
takes care of that, but to show that lock_for_kill() slow path is safe,
we need to demonstrate such rcu_read_lock() scope for any call chain
leading to lock_for_kill(). Which is not fun, seeing that there are
10 such scopes, with 5 distinct beginnings between them.
Case 1: opens in dput() proceeds through fast_dput() grabbing ->d_lock,
returning false into dput() and there a call of finish_dput() which calls
dentry_kill(), which calls lock_for_kill(); ends in dentry_kill(), either
right after lock_for_kill() success or right after dropping ->d_lock
on lock_for_kill() failure. ->d_lock is held continuously all the way
into lock_for_kill().
Case 2: opens in dentry_kill(), where we proceed to the same call of
dentry_kill() as in case 1. ->d_lock is held since before the
beginning of the scope and all the way into lock_for_kill().
Case 3: opens in select_collect2(), proceeds through the return to
d_walk() and to shrink_dcache_tree() where we grab ->d_lock and
proceed to call shrink_kill(), which calls dentry_kill(), then as
in the previous scopes.
Case 4: opens in shrink_dentry_list(), followed by call of shrink_kill(),
then same as in case 3. ->d_lock is held since before the beginning
of the scope and all the way into lock_for_kill().
Case 5: opens in shrink_kill(), where it's immediately followed by
call of dentry_kill(), then same as in the previous scopes. ->d_lock
is held since before the beginning of the scope all the way into
lock_for_kill().
Note that in cases 2, 4 and 5 the slow path of lock_for_kill() is the
only part of rcu_read_lock() scope that is not covered by spinlock
scopes. In case 1 we have the area in fast_dput() as well and in
case 3 - the return path from select_collect2() and chunk in shrink_dcache_tree()
up to grabbing ->d_lock.
Seeing that the reasons we need rcu_read_lock() in these additional
areas are completely unrelated to lock_for_kill() slow path, the things
get much more straightforward with
* explicit rcu_read_lock() scope surrounding the area in slow path
of lock_for_kill() where ->d_lock is not held
* shrink_dentry_list() dropping rcu_read_lock() as soon as it has
grabbed ->d_lock.
* dput() dropping rcu_read_lock() just before calling finish_dput().
* rcu_read_lock() calls in finish_dput(), shrink_kill() and
shrink_dentry_list() are removed, along with rcu_read_unlock() calls in
dentry_kill().
RCU read-side critical areas are unchanged by that, safety of lock_for_kill()
slow path is trivial to verify and a bunch of rcu_read_lock() scopes either
gone or become easier to describe.
Update the comments on locking conventions and memory safety considerations,
including the NORCU case.
Incidentally, all calls of fast_dput() are immediately preceded by rcu_read_lock()
and followed by rcu_read_unlock() now, which will allow to simplify those on
the next step...
Al Viro [Sat, 11 Apr 2026 07:14:19 +0000 (03:14 -0400)]
fold lock_for_kill() and __dentry_kill() into common helper
There are two callers of lock_for_kill() and both are followed
by the same sequence of actions:
* in case of failure, drop ->d_lock, do rcu_read_unlock() and
go away
* in case of success, do rcu_read_unlock() followed by
passing dentry to __dentry_kill(); if the latter returns NULL, go away.
All calls of __dentry_kill() are paired with lock_for_kill() now;
let's turn that sequence into a new helper (dentry_kill()) and switch
to using it.
Al Viro [Sat, 11 Apr 2026 05:52:53 +0000 (01:52 -0400)]
shrink_dentry_list(): start with removing from shrink list
Currently we leave dentry on the list until we are done with
lock_for_kill(). That guarantees that it won't have been
even scheduled for removal until we remove it from the list
and drop ->d_lock. We grab ->d_lock and rcu_read_lock()
and call lock_for_kill(). There are four possible cases:
1) lock_for_kill() has succeeded; dentry and its inode
(if any) are locked, dentry refcount is zero and we can
remove it from shrink list and feed it to shrink_kill().
2) lock_for_kill() fails since dentry has become busy.
Nothing to do, rcu_read_unlock(), remove from shrink list,
drop ->d_lock and move on.
3) lock_for_kill() fails since dentry is currently
being killed - already entered __dentry_kill(), but hasn't
reached dentry_unlist() yet. Nothing to do, we should just
do rcu_read_unlock(), remove from shrink list so that
whoever's executing __dentry_kill() would free it once they
are done, drop ->d_lock and move on - same actions as in
case (2).
4) lock_for_kill() fails since dentry has been killed
(reached dentry_unlist(), DCACHE_DENTRY_KILLED set in ->d_flags).
In that case whoever had been killing it had already seen it
on our shrink list and skipped freeing it. At that point it's
just a passive chunk of memory; rcu_read_unlock(), remove from
the list, drop ->d_lock and use dentry_free() to schedule
freeing.
While that works, there's a simpler way to do it:
* grab ->d_lock
* remove dentry from our shrink list
* if DCACHE_DENTRY_KILLED is already set, drop ->d_lock,
call dentry_free() and move on.
* otherwise grab rcu_read_lock() and call lock_for_free()
* if lock_for_kill() succeeds, feed dentry
to shrink_kill(), otherwise drop the locks and move on.
The end result is equivalent to the old variant. The only difference
arises if at the time we grab ->d_lock dentry had refcount 0 and
lock_for_kill() had failed spin_trylock() and had to drop and regain
->d_lock. Otherwise nobody can observe at which point within the
unbroken ->d_lock scope dentry had been removed from the shrink list -
all accesses to ->d_lru are under ->d_lock.
If ->d_lock had been dropped and regained, it is possible for another
thread to feed that dentry to __dentry_kill(); if it doesn't get to
dentry_unlist() before we regain ->d_lock, behaviour is still identical -
it's case (3) and by the time __dentry_kill() would've gotten around
to checking if the victim is on shrink list, it would've been already
removed from ours.
If __dentry_kill() from another thread *does* get to dentry_unlist(),
in the old variant we would have __dentry_kill() leave calling
dentry_free() to us and in the new one __dentry_kill() would've called
dentry_free() itself. Since we are under rcu_read_lock(), we are
guaranteed that actual freeing won't happen until we get around to
rcu_read_unlock(). IOW, the new variant is still safe wrt UAF, if
not for the same reason as the old one, and overall result is the same;
the only difference is which threads ends up scheduling the actual
freeing of dentry.
Al Viro [Mon, 4 May 2026 06:49:20 +0000 (02:49 -0400)]
d_prune_aliases(): make sure to skip NORCU aliases
Either they are busy (in which case they won't be moved to shrink
list anyway) or they have a zero refcount, in which case we really
shouldn't mess with them - whoever had dropped the refcount to
zero is on the way to evicting and freeing them.
That way we are guaranteed that only the thread that has dropped
refcount of NORCU dentry to zero might call lock_for_kill() and
__dentry_kill() for those.
Al Viro [Mon, 13 Apr 2026 03:39:16 +0000 (23:39 -0400)]
kill d_dispose_if_unused()
Rename to_shrink_list() into __move_to_shrink_list(), document and
export it. Switch d_dispose_if_unused() users to that and kill
d_dispose_if_unused() itself.
Al Viro [Sun, 12 Apr 2026 18:17:52 +0000 (14:17 -0400)]
select_collect(): ignore dentries on shrink lists if they have positive refcounts
If all dentries we find have positive refcounts and some happen
to be on shrink lists, there's no point trying to steal them in the
select_collect2() phase - we won't be able to evict any of them. Busy on
shrink lists is still busy...
Al Viro [Mon, 4 May 2026 03:00:09 +0000 (23:00 -0400)]
fix a race between d_find_any_alias() and final dput() of NORCU dentries
Refcount of a NORCU dentry must not be incremented after having dropped
to zero. Otherwise we might end up with the following race:
CPU1: in fast_dput(d), rcu_read_lock();
CPU1: decrements refcount of d to 0
CPU1: notice that it's unhashed
CPU2: grab a reference to d
CPU2: dput(d), freeing d
CPU1: ... looks like we need to evict d, let's grab ->d_lock, recheck
the refcount, etc.
and that spin_lock(&d->d_lock) ends up a UAF, despite still being in
an RCU read-side critical area started back when the refcount had been
positive. If not for DCACHE_NORCU in d->d_flags freeing would've been
RCU-delayed, so we'd have grabbed ->d_lock, noticed the negative value
stored into refcount by __dentry_kill(), dropped the locks and that would
be it. For NORCU dentries freeing is _not_ delayed, though.
Most of the non-counting references are excluded for NORCU dentries -
they are not allowed to be hashed, they never get placed on LRU, they
never get placed into anyone's list of children and while dput_to_list()
might put them into a shrink list, nobody bumps refcount of something
that had been reached that way.
However, inode's list of aliases can be a problem - it does not contribute
to dentry refcount (for obvious reasons) and we *do* have places that
grab references to something found on that list - that's precisely what
d_find_alias() is. In case of d_find_alias() we are safe - it skips
unhashed aliases, so all NORCU ones are ignored there. d_find_any_alias()
is *not* limited to hashed ones, though, and while it's usually called
for directories (which never get NORCU dentries), there are callers that
use it to get something for non-directories with no hashed aliases.
Having d_find_any_alias() hit a NORCU dentry is not impossible - it can
be easily arranged if you have CAP_DAC_READ_SEARCH (memfd_create() + mmap()
+ name_to_handle_at() for /proc/self/map_files/<...> + munmap() +
open_by_handle_at() will do that, and adding a second memfd_create() for
mount_fd makes it possible to do that without having memfd pinned).
The race window is narrow, and it's probably not feasible on bare hardware,
but...
It's not hard to fix, fortunately:
* separate __d_find_dir_alias() (== current __d_find_any_alias()) to
be used for directory inodes.
* provide dget_alias_ilocked() that would return false for NORCU
dentries with zero refcount and return true incrementing refcount otherwise
* make __d_find_any_alias() go over the list of aliases, using
dget_alias_ilocked() and returning the alias it succeeds on (normally the
first one). Any NORCU alias with zero refcount is going to be evicted by
the thread that had dropped the final reference; this makes __d_find_any_alias()
pretend it had lost the race with eviction.
Al Viro [Mon, 27 Apr 2026 18:19:28 +0000 (14:19 -0400)]
alloc_path_pseudo(): make sure we don't end up with NORCU dentries for directories
A lot of places relies upon directories never having NORCU dentries;
currently that property holds, but the proof is not straightforward
and rather brittle.
It's better to have that verified in the sole caller of d_alloc_pseudo(),
so that any future bugs in that direction were caught early.
That way we can be sure that
* current directory of any process is not NORCU
* root directory of any process is not NORCU
* starting point of any LOOKUP_RCU pathwalk is not NORCU
* dget_parent() can rely upon ->d_parent not being NORCU
* d_walk() and is_subdir() can rely upon the same
* alloc_file_pseudo() won't create multiple aliases for a directory
without having to go through a convoluted audit.
VFS: use wait_var_event for waiting in d_alloc_parallel()
Parallel lookup starts with a call of d_alloc_parallel(). That primitive
either returns a matching hashed dentry or allocates a new one in the
in-lookup state and returns it to the caller. Once the caller is done
with lookup, it indicates so either by call of d_{splice_alias,add}()
or by call of d_done_lookup(); at that point dentry leaves the in-lookup
state.
If d_alloc_parallel() finds a matching in-lookup dentry, it must wait for
that dentry to leave the in-lookup state, one way or another. Currently
by supplying wait_queue_head to d_alloc_parallel(). If d_alloc_parallel()
creates a new in-lookup dentry, the address of that wait_queue_head is stored
in ->d_wait of new dentry and stays there while it's in the in-lookup;
subsequent d_alloc_parallel() will wait on the queue found in the matching
in-lookup dentry. Transition out of in-lookup state wakes waiters on that
queue (if any).
That works, but the calling conventions are inconvenient - the caller must
supply wait_queue_head and make sure that it survives at least until the new
in-lookup dentry leaves the in-lookup state. That amounts to boilerplate
in the d_alloc_parallel() callers that are followed by a call of d_lookup_done()
in the same function; in cases like nfs asynchronous unlink it gets worse than
that.
This patch changes d_alloc_parallel() to use wake_up_var_locked() to
wake up waiters, and wait_var_event_spinlock() to wait. dentry->d_lock
is used for synchronisation as it is already held and the relevant
times.
That eliminates the need of caller-supplied wait_queue_head, simplifying
the calling conventions. Better yet, we only need one bit of information
stored in dentry itself: whether there are any waiters to be woken up,
and that can be easily stored in ->d_flags; ->d_wait goes away.
The reason we need that bit (DCACHE_LOOKUP_WAITERS) is that with wait_var
machinery the queues are shared with all kinds of stuff and there's
no way tell if any of the waiters have anything to do with our dentry;
most of the time none of them will be relevant, so we need to avoid the
pointless wakeups.
Another benefit of the new scheme comes from the fact that wakeups
have to be done outside of write-side critical areas of ->i_dir_seq;
with the old scheme we need to carry the value picked from ->d_wait from
__d_lookup_unhash() to the place where we actually wake the waiters up.
Now we can just leave DCACHE_LOOKUP_WAITERS in ->d_flags until we get
to doing wakeups - that's done within the same ->d_lock scope, so we
are fine; new bit is accessed only under ->d_lock and it's seen only
on dentries with DCACHE_PAR_LOOKUP in ->d_flags.
__d_lookup_unhash() no longer needs to re-init ->d_lru. That was
previously shared (in a union) with ->d_wait but ->d_wait is now gone
so it no longer corrupts ->d_lru.
Co-developed-by: Al Viro <viro@zeniv.linux.org.uk> # saner handling of flags Signed-off-by: NeilBrown <neil@brown.name> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Muhammad Bilal [Sat, 23 May 2026 19:08:43 +0000 (19:08 +0000)]
accel/ethosu: fix OOB write in ethosu_gem_cmdstream_copy_and_validate()
The command stream parsing loop increments the index variable a second
time when a 64-bit command word is encountered (bit 14 set), but does
not re-check the loop bound before writing the second word:
for (i = 0; i < size / 4; i++) {
bocmds[i] = cmds[0];
if (cmd & 0x4000) {
i++;
bocmds[i] = cmds[1]; /* unchecked */
}
}
The buffer bocmds is backed by a DMA allocation of exactly size bytes
from drm_gem_dma_create(ddev, size), giving valid indices [0, size/4-1].
When i == size/4 - 1 on entry to an iteration and bit 14 of cmds[0] is
set, bocmds[size/4-1] is written in bounds, i is then incremented to
size/4, and bocmds[size/4] writes four bytes past the end of the
allocation.
Userspace controls both the buffer contents and the size argument via
the ioctl, making this a userspace-triggerable heap out-of-bounds write.
Fix by checking the incremented index against the buffer bound before
the second write and returning -EINVAL if the buffer is too small to
contain the extended command.
Jakub Kicinski [Fri, 5 Jun 2026 02:14:35 +0000 (19:14 -0700)]
Merge tag 'batadv-next-pullrequest-20260603' of https://git.open-mesh.org/batadv
Simon Wunderlich says:
====================
This cleanup patchset includes the following patches, all by
Sven Eckelmann:
- tp_meter: fix various minor issues (8 patches)
- tp_meter: split generic session type in sender and receiver type
- tp_meter: consolidate locking for congestion control (2 patches)
- bla: annotate lasttime access with READ/WRITE_ONCE
- elp: prevent transmission interval underflow
- tt: sync local and global tvlv preparation return values
- tt: directly retrieve wifi flags of net_device
* tag 'batadv-next-pullrequest-20260603' of https://git.open-mesh.org/batadv:
batman-adv: tt: directly retrieve wifi flags of net_device
batman-adv: tt: sync local and global tvlv preparation return values
batman-adv: prevent ELP transmission interval underflow
batman-adv: bla: annotate lasttime access with READ/WRITE_ONCE
batman-adv: tp_meter: consolidate congestion control variables
batman-adv: tp_meter: use locking for all congestion control variables
batman-adv: tp_meter: split vars into sender and receiver types
batman-adv: tp_meter: add only finished tp_vars to lists
batman-adv: tp_meter: handle seqno wrap-around for fast recovery detection
batman-adv: tp_meter: fix fast recovery precondition
batman-adv: tp_meter: avoid divide-by-zero for dec_cwnd
batman-adv: tp_meter: avoid window underflow
batman-adv: tp_meter: initialize dec_cwnd explicitly
batman-adv: tp_meter: initialize dup_acks explicitly
batman-adv: tp_meter: keep unacked list in ascending ordered
====================
Platform devices created with platform_device_alloc() call
platform_device_release() when the last reference to the device's
kobject is dropped. This function calls of_node_put() unconditionally.
This works fine for devices created with platform_device_register_full()
but users of the split approach (platform_device_alloc() +
platform_device_add()) must bump the reference of the of_node they
assign manually. Add the missing call to of_node_get().
Kiran Kumar K [Tue, 2 Jun 2026 04:05:25 +0000 (09:35 +0530)]
octeontx2-af: kpu: Default profile updates
Add support for parsing the following:
1. fabric path header
2. tpids 0x88a8, 0x9100 and 0x9200 parsing for
first pass and second pass packets
3. parse stacked VLANs
4. RoCEv2 header with UDP destination port 4791
5. single SBTAG parsing
====================
selftests: rds: ROCE support follow ups
This is a follow up series to the "Add ROCE support to rds selftests"
series. The first patch renames run.sh to rds_run.sh, which provides
a self-describing name that appears on the netdev CI dashboard.
The second patch addresses a sashiko complaint that I thought was
worth circling back for. In the patch "pin RDS sockets to their
intended transport," sockets are pinned to the specific transport they
are meant to test. By default, socket transports are implicitly
selected based on the network topology, but it is possible that they
can fail back to other transports if the underlying connection could
not be established. So the patch pins them to the intended transport
to avoid false positives.
The third patch "support RDS built as loadable modules," lifts the
CONFIG_MODULES=n requirement, and updates the check_*conf_enabled()
to allow modules set to "=m" and further load the backing modules for
any component set as such. config.sh is updated to match.
The fourth patch converts the rdma-prerequisite checks to return XFAIL
rather than SKIP, since the RDMA datapath is not run in netdev CI.
Questions, comments and feedback appreciated!
====================
selftests: rds: report missing RDMA prereqs as XFAIL
Make the RDMA test return XFAIL rather than skip when RXE is not
available, since the RDMA datapath is not run in netdev CI.
Change the three RDMA-prerequisite checks in check_rdma_conf() and
check_rdma_conf_enabled() to exit with KSFT_XFAIL (2) and tag their
messages [XFAIL] instead of [SKIP].
selftests: rds: support RDS built as loadable modules
Commit 92cc6708f4a2 ("selftests: rds: config: disable modules") set
CONFIG_MODULES=n since run.sh required this kconfig. But disabling
modules also forces every =m option to =n rather than =y, which can
silently drop unrelated features.
This patch removes CONFIG_MODULES=n from the rds selftest config and
updates the check_*conf_enabled() routines to accept a config as
either built-in (=y) or modular (=m). A new probe_module() function
is added to load the backing module when a component is set to be
modular (=m). config.sh no longer forces CONFIG_MODULES=n, so a user
who follows the SKIP message to run config.sh does not silently end
up with modules disabled again.
rds.ko itself is auto-loaded on socket creation, and rds_rdma.ko is
auto-loaded when SO_RDS_TRANSPORT is set with RDS_TRANS_IB, but the
TCP transport (rds_tcp.ko) is not auto-loaded on the bind path, so
the backing modules are loaded explicitly here.
selftests: rds: pin RDS sockets to their intended transport
The RDS selftests create AF_RDS sockets but never selects a transport,
so the transport is chosen implicitly based on network topology when
the socket is bound. If underlying connection establishment fails, RDS
can fall back to another transport (e.g. loopback) and the test still
passes, silently bypassing the intended datapath it is meant to
exercise.
Set SO_RDS_TRANSPORT to the proper RDS_TRANS_IB or RDS_TRANS_TCP before
they are bound, so the test fails loudly if the intended transport is
unavailable rather than passing on a different path.
Akash Sukhavasi [Wed, 3 Jun 2026 20:42:20 +0000 (15:42 -0500)]
dt-bindings: net: dsa: remove obsolete dsa.txt
dsa.txt has been a redirect to dsa.yaml since commit bce58590d1bd
("dt-bindings: net: dsa: Add DSA yaml binding") introduced the .yaml
schema. The .yaml has the same filename in the same directory, making
this redirect unnecessary for discoverability.
Two files still reference dsa.txt, forcing readers through an extra
hop to reach the .yaml. The stub has not been touched since August
2020. Update references in lan9303.txt and
Documentation/networking/dsa/dsa.rst to point directly to dsa.yaml
and remove the stub.
Akash Sukhavasi [Wed, 3 Jun 2026 20:42:18 +0000 (15:42 -0500)]
dt-bindings: net: remove obsolete mdio.txt
mdio.txt has been a single-line redirect to mdio.yaml since
commit 62d77ff7ecbf ("dt-bindings: net: Add a YAML schemas for the
generic MDIO options"), which introduced the .yaml schema and reduced
the .txt to a stub in the same change. The .yaml has the same filename
in the same directory, making this redirect unnecessary for
discoverability.
No files in the tree reference mdio.txt and it has not been touched
since June 2019. Remove the obsolete stub.
Eric Dumazet [Wed, 3 Jun 2026 18:08:31 +0000 (18:08 +0000)]
rtnetlink: use dev_isalive() in rtnl_getlink()
rtnl_getlink() uses an RCU lookup to get the netdevice pointer.
When/If rtnl_lock() is used, we should check if the netdevice is not
being dismantled before potentially perform illegal actions.
Move dev_isalive() out of net/core/net-sysfs.c and make it available
in net/core/dev.h.
Return -ENODEV if rtnl_getlink() finds a device which is currently
being dismantled and RTNL is requested.
Fixes: e896e5c0734b ("rtnetlink: do not acquire RTNL in rtnl_getlink() with RTEXT_FILTER_NAME_ONLY") Signed-off-by: Eric Dumazet <edumazet@google.com> Suggested-by: Jakub Kicinski <kuba@kernel.org> Reviewed-by: Jiayuan Chen <jiayuan.chen@linux.dev> Link: https://patch.msgid.link/20260603180831.1024716-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Ido Schimmel [Wed, 3 Jun 2026 10:35:22 +0000 (13:35 +0300)]
bridge: mcast: Synchronously shutdown port multicast timers
Currently, while four timers are set up during port multicast context
initialization, only two are synchronously deleted when the context is
de-initialized, just before being deleted.
This is fine because the structure containing the multicast context
(either a bridge port or a VLAN) is only deleted after an RCU grace
period and it will not pass as long as the timers are executing. These
timers are also not supposed to do any work at this stage. They acquire
the bridge multicast lock, see that the multicast context was disabled
and exit.
Make the code more explicit and symmetric and synchronously shutdown all
four timers when the multicast context is de-initialized. Use
timer_shutdown_sync() to guarantee that the timers will not be re-armed
given that the containing structure is being deleted.
projects / thirdparty / kernel / stable.git / log
