--- /dev/null
+From 0711f0d7050b9e07c44bc159bbc64ac0a1022c7f Mon Sep 17 00:00:00 2001
+From: Mark Rutland <mark.rutland@arm.com>
+Date: Fri, 4 Jun 2021 20:01:14 -0700
+Subject: pid: take a reference when initializing `cad_pid`
+
+From: Mark Rutland <mark.rutland@arm.com>
+
+commit 0711f0d7050b9e07c44bc159bbc64ac0a1022c7f upstream.
+
+During boot, kernel_init_freeable() initializes `cad_pid` to the init
+task's struct pid. Later on, we may change `cad_pid` via a sysctl, and
+when this happens proc_do_cad_pid() will increment the refcount on the
+new pid via get_pid(), and will decrement the refcount on the old pid
+via put_pid(). As we never called get_pid() when we initialized
+`cad_pid`, we decrement a reference we never incremented, can therefore
+free the init task's struct pid early. As there can be dangling
+references to the struct pid, we can later encounter a use-after-free
+(e.g. when delivering signals).
+
+This was spotted when fuzzing v5.13-rc3 with Syzkaller, but seems to
+have been around since the conversion of `cad_pid` to struct pid in
+commit 9ec52099e4b8 ("[PATCH] replace cad_pid by a struct pid") from the
+pre-KASAN stone age of v2.6.19.
+
+Fix this by getting a reference to the init task's struct pid when we
+assign it to `cad_pid`.
+
+Full KASAN splat below.
+
+ ==================================================================
+ BUG: KASAN: use-after-free in ns_of_pid include/linux/pid.h:153 [inline]
+ BUG: KASAN: use-after-free in task_active_pid_ns+0xc0/0xc8 kernel/pid.c:509
+ Read of size 4 at addr ffff23794dda0004 by task syz-executor.0/273
+
+ CPU: 1 PID: 273 Comm: syz-executor.0 Not tainted 5.12.0-00001-g9aef892b2d15 #1
+ Hardware name: linux,dummy-virt (DT)
+ Call trace:
+ ns_of_pid include/linux/pid.h:153 [inline]
+ task_active_pid_ns+0xc0/0xc8 kernel/pid.c:509
+ do_notify_parent+0x308/0xe60 kernel/signal.c:1950
+ exit_notify kernel/exit.c:682 [inline]
+ do_exit+0x2334/0x2bd0 kernel/exit.c:845
+ do_group_exit+0x108/0x2c8 kernel/exit.c:922
+ get_signal+0x4e4/0x2a88 kernel/signal.c:2781
+ do_signal arch/arm64/kernel/signal.c:882 [inline]
+ do_notify_resume+0x300/0x970 arch/arm64/kernel/signal.c:936
+ work_pending+0xc/0x2dc
+
+ Allocated by task 0:
+ slab_post_alloc_hook+0x50/0x5c0 mm/slab.h:516
+ slab_alloc_node mm/slub.c:2907 [inline]
+ slab_alloc mm/slub.c:2915 [inline]
+ kmem_cache_alloc+0x1f4/0x4c0 mm/slub.c:2920
+ alloc_pid+0xdc/0xc00 kernel/pid.c:180
+ copy_process+0x2794/0x5e18 kernel/fork.c:2129
+ kernel_clone+0x194/0x13c8 kernel/fork.c:2500
+ kernel_thread+0xd4/0x110 kernel/fork.c:2552
+ rest_init+0x44/0x4a0 init/main.c:687
+ arch_call_rest_init+0x1c/0x28
+ start_kernel+0x520/0x554 init/main.c:1064
+ 0x0
+
+ Freed by task 270:
+ slab_free_hook mm/slub.c:1562 [inline]
+ slab_free_freelist_hook+0x98/0x260 mm/slub.c:1600
+ slab_free mm/slub.c:3161 [inline]
+ kmem_cache_free+0x224/0x8e0 mm/slub.c:3177
+ put_pid.part.4+0xe0/0x1a8 kernel/pid.c:114
+ put_pid+0x30/0x48 kernel/pid.c:109
+ proc_do_cad_pid+0x190/0x1b0 kernel/sysctl.c:1401
+ proc_sys_call_handler+0x338/0x4b0 fs/proc/proc_sysctl.c:591
+ proc_sys_write+0x34/0x48 fs/proc/proc_sysctl.c:617
+ call_write_iter include/linux/fs.h:1977 [inline]
+ new_sync_write+0x3ac/0x510 fs/read_write.c:518
+ vfs_write fs/read_write.c:605 [inline]
+ vfs_write+0x9c4/0x1018 fs/read_write.c:585
+ ksys_write+0x124/0x240 fs/read_write.c:658
+ __do_sys_write fs/read_write.c:670 [inline]
+ __se_sys_write fs/read_write.c:667 [inline]
+ __arm64_sys_write+0x78/0xb0 fs/read_write.c:667
+ __invoke_syscall arch/arm64/kernel/syscall.c:37 [inline]
+ invoke_syscall arch/arm64/kernel/syscall.c:49 [inline]
+ el0_svc_common.constprop.1+0x16c/0x388 arch/arm64/kernel/syscall.c:129
+ do_el0_svc+0xf8/0x150 arch/arm64/kernel/syscall.c:168
+ el0_svc+0x28/0x38 arch/arm64/kernel/entry-common.c:416
+ el0_sync_handler+0x134/0x180 arch/arm64/kernel/entry-common.c:432
+ el0_sync+0x154/0x180 arch/arm64/kernel/entry.S:701
+
+ The buggy address belongs to the object at ffff23794dda0000
+ which belongs to the cache pid of size 224
+ The buggy address is located 4 bytes inside of
+ 224-byte region [ffff23794dda0000, ffff23794dda00e0)
+ The buggy address belongs to the page:
+ page:(____ptrval____) refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x4dda0
+ head:(____ptrval____) order:1 compound_mapcount:0
+ flags: 0x3fffc0000010200(slab|head)
+ raw: 03fffc0000010200 dead000000000100 dead000000000122 ffff23794d40d080
+ raw: 0000000000000000 0000000000190019 00000001ffffffff 0000000000000000
+ page dumped because: kasan: bad access detected
+
+ Memory state around the buggy address:
+ ffff23794dd9ff00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
+ ffff23794dd9ff80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
+ >ffff23794dda0000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
+ ^
+ ffff23794dda0080: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
+ ffff23794dda0100: fc fc fc fc fc fc fc fc 00 00 00 00 00 00 00 00
+ ==================================================================
+
+Link: https://lkml.kernel.org/r/20210524172230.38715-1-mark.rutland@arm.com
+Fixes: 9ec52099e4b8678a ("[PATCH] replace cad_pid by a struct pid")
+Signed-off-by: Mark Rutland <mark.rutland@arm.com>
+Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
+Cc: Cedric Le Goater <clg@fr.ibm.com>
+Cc: Christian Brauner <christian@brauner.io>
+Cc: Eric W. Biederman <ebiederm@xmission.com>
+Cc: Kees Cook <keescook@chromium.org
+Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
+Cc: Paul Mackerras <paulus@samba.org>
+Cc: <stable@vger.kernel.org>
+Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
+Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ init/main.c | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+--- a/init/main.c
++++ b/init/main.c
+@@ -1054,7 +1054,7 @@ static noinline void __init kernel_init_
+ */
+ set_mems_allowed(node_states[N_MEMORY]);
+
+- cad_pid = task_pid(current);
++ cad_pid = get_pid(task_pid(current));
+
+ smp_prepare_cpus(setup_max_cpus);
+
--- /dev/null
+From phil@raspberrypi.com Tue Jun 8 15:06:41 2021
+From: Phil Elwell <phil@raspberrypi.com>
+Date: Tue, 8 Jun 2021 13:00:49 +0100
+Subject: usb: dwc2: Fix build in periphal-only mode
+To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>, stable@vger.kernel.org
+Cc: Phil Elwell <phil@raspberrypi.com>
+Message-ID: <20210608120049.1393123-1-phil@raspberrypi.com>
+
+From: Phil Elwell <phil@raspberrypi.com>
+
+In branches to which 24d209dba5a3 ("usb: dwc2: Fix hibernation between
+host and device modes.") has been back-ported, the bus_suspended member
+of struct dwc2_hsotg is only present in builds that support host-mode.
+To avoid having to pull in several more non-Fix commits in order to
+get it to compile, wrap the usage of the member in a macro conditional.
+
+Fixes: 24d209dba5a3 ("usb: dwc2: Fix hibernation between host and device modes.")
+Signed-off-by: Phil Elwell <phil@raspberrypi.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+--- a/drivers/usb/dwc2/core_intr.c
++++ b/drivers/usb/dwc2/core_intr.c
+@@ -725,7 +725,11 @@ static inline void dwc_handle_gpwrdn_disc_det(struct dwc2_hsotg *hsotg,
+ dwc2_writel(hsotg, gpwrdn_tmp, GPWRDN);
+
+ hsotg->hibernated = 0;
++
++#if IS_ENABLED(CONFIG_USB_DWC2_HOST) || \
++ IS_ENABLED(CONFIG_USB_DWC2_DUAL_ROLE)
+ hsotg->bus_suspended = 0;
++#endif
+
+ if (gpwrdn & GPWRDN_IDSTS) {
+ hsotg->op_state = OTG_STATE_B_PERIPHERAL;
+--
+2.25.1
+