]> git.ipfire.org Git - thirdparty/kernel/stable-queue.git/commitdiff
4.19-stable patches
authorGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Sun, 24 Mar 2019 20:15:38 +0000 (21:15 +0100)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Sun, 24 Mar 2019 20:15:38 +0000 (21:15 +0100)
added patches:
cifs-allow-guest-mounts-to-work-for-smb3.11.patch
futex-ensure-that-futex-address-is-aligned-in-handle_futex_death.patch
irqchip-gic-v3-its-fix-comparison-logic-in-lpi_range_cmp.patch
objtool-move-objtool_file-struct-off-the-stack.patch
perf-probe-fix-getting-the-kernel-map.patch
scsi-ibmvscsi-fix-empty-event-pool-access-during-host-removal.patch
scsi-ibmvscsi-protect-ibmvscsi_head-from-concurrent-modificaiton.patch
smb3-fix-smb3.1.1-guest-mounts-to-samba.patch

queue-4.19/cifs-allow-guest-mounts-to-work-for-smb3.11.patch [new file with mode: 0644]
queue-4.19/futex-ensure-that-futex-address-is-aligned-in-handle_futex_death.patch [new file with mode: 0644]
queue-4.19/irqchip-gic-v3-its-fix-comparison-logic-in-lpi_range_cmp.patch [new file with mode: 0644]
queue-4.19/objtool-move-objtool_file-struct-off-the-stack.patch [new file with mode: 0644]
queue-4.19/perf-probe-fix-getting-the-kernel-map.patch [new file with mode: 0644]
queue-4.19/scsi-ibmvscsi-fix-empty-event-pool-access-during-host-removal.patch [new file with mode: 0644]
queue-4.19/scsi-ibmvscsi-protect-ibmvscsi_head-from-concurrent-modificaiton.patch [new file with mode: 0644]
queue-4.19/series
queue-4.19/smb3-fix-smb3.1.1-guest-mounts-to-samba.patch [new file with mode: 0644]

diff --git a/queue-4.19/cifs-allow-guest-mounts-to-work-for-smb3.11.patch b/queue-4.19/cifs-allow-guest-mounts-to-work-for-smb3.11.patch
new file mode 100644 (file)
index 0000000..1444d92
--- /dev/null
@@ -0,0 +1,45 @@
+From e71ab2aa06f731a944993120b0eef1556c63b81c Mon Sep 17 00:00:00 2001
+From: Ronnie Sahlberg <lsahlber@redhat.com>
+Date: Thu, 21 Mar 2019 14:59:02 +1000
+Subject: cifs: allow guest mounts to work for smb3.11
+
+From: Ronnie Sahlberg <lsahlber@redhat.com>
+
+commit e71ab2aa06f731a944993120b0eef1556c63b81c upstream.
+
+Fix Guest/Anonymous sessions so that they work with SMB 3.11.
+
+The commit noted below tightened the conditions and forced signing for
+the SMB2-TreeConnect commands as per MS-SMB2.
+However, this should only apply to normal user sessions and not for
+Guest/Anonumous sessions.
+
+Fixes: 6188f28bf608 ("Tree connect for SMB3.1.1 must be signed for non-encrypted shares")
+
+Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
+CC: Stable <stable@vger.kernel.org>
+Signed-off-by: Steve French <stfrench@microsoft.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+---
+ fs/cifs/smb2pdu.c |    8 ++++++--
+ 1 file changed, 6 insertions(+), 2 deletions(-)
+
+--- a/fs/cifs/smb2pdu.c
++++ b/fs/cifs/smb2pdu.c
+@@ -1500,9 +1500,13 @@ SMB2_tcon(const unsigned int xid, struct
+       iov[1].iov_base = unc_path;
+       iov[1].iov_len = unc_path_len;
+-      /* 3.11 tcon req must be signed if not encrypted. See MS-SMB2 3.2.4.1.1 */
++      /*
++       * 3.11 tcon req must be signed if not encrypted. See MS-SMB2 3.2.4.1.1
++       * unless it is guest or anonymous user. See MS-SMB2 3.2.5.3.1
++       */
+       if ((ses->server->dialect == SMB311_PROT_ID) &&
+-          !smb3_encryption_required(tcon))
++          !smb3_encryption_required(tcon) &&
++          !(ses->session_flags & (SMB2_SESSION_FLAG_IS_GUEST|SMB2_SESSION_FLAG_IS_NULL)))
+               req->sync_hdr.Flags |= SMB2_FLAGS_SIGNED;
+       memset(&rqst, 0, sizeof(struct smb_rqst));
diff --git a/queue-4.19/futex-ensure-that-futex-address-is-aligned-in-handle_futex_death.patch b/queue-4.19/futex-ensure-that-futex-address-is-aligned-in-handle_futex_death.patch
new file mode 100644 (file)
index 0000000..748be9c
--- /dev/null
@@ -0,0 +1,47 @@
+From 5a07168d8d89b00fe1760120714378175b3ef992 Mon Sep 17 00:00:00 2001
+From: Chen Jie <chenjie6@huawei.com>
+Date: Fri, 15 Mar 2019 03:44:38 +0000
+Subject: futex: Ensure that futex address is aligned in handle_futex_death()
+
+From: Chen Jie <chenjie6@huawei.com>
+
+commit 5a07168d8d89b00fe1760120714378175b3ef992 upstream.
+
+The futex code requires that the user space addresses of futexes are 32bit
+aligned. sys_futex() checks this in futex_get_keys() but the robust list
+code has no alignment check in place.
+
+As a consequence the kernel crashes on architectures with strict alignment
+requirements in handle_futex_death() when trying to cmpxchg() on an
+unaligned futex address which was retrieved from the robust list.
+
+[ tglx: Rewrote changelog, proper sizeof() based alignement check and add
+       comment ]
+
+Fixes: 0771dfefc9e5 ("[PATCH] lightweight robust futexes: core")
+Signed-off-by: Chen Jie <chenjie6@huawei.com>
+Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
+Cc: <dvhart@infradead.org>
+Cc: <peterz@infradead.org>
+Cc: <zengweilin@huawei.com>
+Cc: stable@vger.kernel.org
+Link: https://lkml.kernel.org/r/1552621478-119787-1-git-send-email-chenjie6@huawei.com
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+---
+ kernel/futex.c |    4 ++++
+ 1 file changed, 4 insertions(+)
+
+--- a/kernel/futex.c
++++ b/kernel/futex.c
+@@ -3432,6 +3432,10 @@ int handle_futex_death(u32 __user *uaddr
+ {
+       u32 uval, uninitialized_var(nval), mval;
++      /* Futex address must be 32bit aligned */
++      if ((((unsigned long)uaddr) % sizeof(*uaddr)) != 0)
++              return -1;
++
+ retry:
+       if (get_user(uval, uaddr))
+               return -1;
diff --git a/queue-4.19/irqchip-gic-v3-its-fix-comparison-logic-in-lpi_range_cmp.patch b/queue-4.19/irqchip-gic-v3-its-fix-comparison-logic-in-lpi_range_cmp.patch
new file mode 100644 (file)
index 0000000..f3a8add
--- /dev/null
@@ -0,0 +1,36 @@
+From 89dc891792c2e046b030f87600109c22209da32e Mon Sep 17 00:00:00 2001
+From: Rasmus Villemoes <linux@rasmusvillemoes.dk>
+Date: Tue, 12 Mar 2019 18:33:46 +0100
+Subject: irqchip/gic-v3-its: Fix comparison logic in lpi_range_cmp
+
+From: Rasmus Villemoes <linux@rasmusvillemoes.dk>
+
+commit 89dc891792c2e046b030f87600109c22209da32e upstream.
+
+The lpi_range_list is supposed to be sorted in ascending order of
+->base_id (at least if the range merging is to work), but the current
+comparison function returns a positive value if rb->base_id >
+ra->base_id, which means that list_sort() will put A after B in that
+case - and vice versa, of course.
+
+Fixes: 880cb3cddd16 (irqchip/gic-v3-its: Refactor LPI allocator)
+Cc: stable@vger.kernel.org (v4.19+)
+Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
+Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+---
+ drivers/irqchip/irq-gic-v3-its.c |    2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+--- a/drivers/irqchip/irq-gic-v3-its.c
++++ b/drivers/irqchip/irq-gic-v3-its.c
+@@ -1477,7 +1477,7 @@ static int lpi_range_cmp(void *priv, str
+       ra = container_of(a, struct lpi_range, entry);
+       rb = container_of(b, struct lpi_range, entry);
+-      return rb->base_id - ra->base_id;
++      return ra->base_id - rb->base_id;
+ }
+ static void merge_lpi_ranges(void)
diff --git a/queue-4.19/objtool-move-objtool_file-struct-off-the-stack.patch b/queue-4.19/objtool-move-objtool_file-struct-off-the-stack.patch
new file mode 100644 (file)
index 0000000..a056bb8
--- /dev/null
@@ -0,0 +1,42 @@
+From 0c671812f152b628bd87c0af49da032cc2a2c319 Mon Sep 17 00:00:00 2001
+From: Josh Poimboeuf <jpoimboe@redhat.com>
+Date: Mon, 18 Mar 2019 19:09:38 -0500
+Subject: objtool: Move objtool_file struct off the stack
+
+From: Josh Poimboeuf <jpoimboe@redhat.com>
+
+commit 0c671812f152b628bd87c0af49da032cc2a2c319 upstream.
+
+Objtool uses over 512k of stack, thanks to the hash table embedded in
+the objtool_file struct.  This causes an unnecessarily large stack
+allocation and breaks users with low stack limits.
+
+Move the struct off the stack.
+
+Fixes: 042ba73fe7eb ("objtool: Add several performance improvements")
+Reported-by: Vassili Karpov <moosotc@gmail.com>
+Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
+Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
+Cc: Peter Zijlstra <peterz@infradead.org>
+Cc: stable@vger.kernel.org
+Link: https://lkml.kernel.org/r/df92dcbc4b84b02ffa252f46876df125fb56e2d7.1552954176.git.jpoimboe@redhat.com
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+---
+ tools/objtool/check.c |    3 ++-
+ 1 file changed, 2 insertions(+), 1 deletion(-)
+
+--- a/tools/objtool/check.c
++++ b/tools/objtool/check.c
+@@ -2157,9 +2157,10 @@ static void cleanup(struct objtool_file
+       elf_close(file->elf);
+ }
++static struct objtool_file file;
++
+ int check(const char *_objname, bool orc)
+ {
+-      struct objtool_file file;
+       int ret, warnings = 0;
+       objname = _objname;
diff --git a/queue-4.19/perf-probe-fix-getting-the-kernel-map.patch b/queue-4.19/perf-probe-fix-getting-the-kernel-map.patch
new file mode 100644 (file)
index 0000000..3f1dbaf
--- /dev/null
@@ -0,0 +1,50 @@
+From eaeffeb9838a7c0dec981d258666bfcc0fa6a947 Mon Sep 17 00:00:00 2001
+From: Adrian Hunter <adrian.hunter@intel.com>
+Date: Mon, 4 Mar 2019 15:13:21 +0200
+Subject: perf probe: Fix getting the kernel map
+
+From: Adrian Hunter <adrian.hunter@intel.com>
+
+commit eaeffeb9838a7c0dec981d258666bfcc0fa6a947 upstream.
+
+Since commit 4d99e4136580 ("perf machine: Workaround missing maps for
+x86 PTI entry trampolines"), perf tools has been creating more than one
+kernel map, however 'perf probe' assumed there could be only one.
+
+Fix by using machine__kernel_map() to get the main kernel map.
+
+Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
+Tested-by: Joseph Qi <joseph.qi@linux.alibaba.com>
+Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
+Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
+Cc: Andy Lutomirski <luto@kernel.org>
+Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+Cc: Jiufei Xue <jiufei.xue@linux.alibaba.com>
+Cc: Peter Zijlstra <peterz@infradead.org>
+Cc: stable@vger.kernel.org
+Cc: Xu Yu <xuyu@linux.alibaba.com>
+Fixes: 4d99e4136580 ("perf machine: Workaround missing maps for x86 PTI entry trampolines")
+Fixes: d83212d5dd67 ("kallsyms, x86: Export addresses of PTI entry trampolines")
+Link: http://lkml.kernel.org/r/2ed432de-e904-85d2-5c36-5897ddc5b23b@intel.com
+Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+---
+ tools/perf/util/probe-event.c |    6 ++++--
+ 1 file changed, 4 insertions(+), 2 deletions(-)
+
+--- a/tools/perf/util/probe-event.c
++++ b/tools/perf/util/probe-event.c
+@@ -157,8 +157,10 @@ static struct map *kernel_get_module_map
+       if (module && strchr(module, '/'))
+               return dso__new_map(module);
+-      if (!module)
+-              module = "kernel";
++      if (!module) {
++              pos = machine__kernel_map(host_machine);
++              return map__get(pos);
++      }
+       for (pos = maps__first(maps); pos; pos = map__next(pos)) {
+               /* short_name is "[module]" */
diff --git a/queue-4.19/scsi-ibmvscsi-fix-empty-event-pool-access-during-host-removal.patch b/queue-4.19/scsi-ibmvscsi-fix-empty-event-pool-access-during-host-removal.patch
new file mode 100644 (file)
index 0000000..a5fcf01
--- /dev/null
@@ -0,0 +1,93 @@
+From 7f5203c13ba8a7b7f9f6ecfe5a4d5567188d7835 Mon Sep 17 00:00:00 2001
+From: Tyrel Datwyler <tyreld@linux.vnet.ibm.com>
+Date: Wed, 20 Mar 2019 13:41:51 -0500
+Subject: scsi: ibmvscsi: Fix empty event pool access during host removal
+
+From: Tyrel Datwyler <tyreld@linux.vnet.ibm.com>
+
+commit 7f5203c13ba8a7b7f9f6ecfe5a4d5567188d7835 upstream.
+
+The event pool used for queueing commands is destroyed fairly early in the
+ibmvscsi_remove() code path. Since, this happens prior to the call so
+scsi_remove_host() it is possible for further calls to queuecommand to be
+processed which manifest as a panic due to a NULL pointer dereference as
+seen here:
+
+PANIC: "Unable to handle kernel paging request for data at address
+0x00000000"
+
+Context process backtrace:
+
+DSISR: 0000000042000000 ????Syscall Result: 0000000000000000
+4 [c000000002cb3820] memcpy_power7 at c000000000064204
+[Link Register] [c000000002cb3820] ibmvscsi_send_srp_event at d000000003ed14a4
+5 [c000000002cb3920] ibmvscsi_send_srp_event at d000000003ed14a4 [ibmvscsi] ?(unreliable)
+6 [c000000002cb39c0] ibmvscsi_queuecommand at d000000003ed2388 [ibmvscsi]
+7 [c000000002cb3a70] scsi_dispatch_cmd at d00000000395c2d8 [scsi_mod]
+8 [c000000002cb3af0] scsi_request_fn at d00000000395ef88 [scsi_mod]
+9 [c000000002cb3be0] __blk_run_queue at c000000000429860
+10 [c000000002cb3c10] blk_delay_work at c00000000042a0ec
+11 [c000000002cb3c40] process_one_work at c0000000000dac30
+12 [c000000002cb3cd0] worker_thread at c0000000000db110
+13 [c000000002cb3d80] kthread at c0000000000e3378
+14 [c000000002cb3e30] ret_from_kernel_thread at c00000000000982c
+
+The kernel buffer log is overfilled with this log:
+
+[11261.952732] ibmvscsi: found no event struct in pool!
+
+This patch reorders the operations during host teardown. Start by calling
+the SRP transport and Scsi_Host remove functions to flush any outstanding
+work and set the host offline. LLDD teardown follows including destruction
+of the event pool, freeing the Command Response Queue (CRQ), and unmapping
+any persistent buffers. The event pool destruction is protected by the
+scsi_host lock, and the pool is purged prior of any requests for which we
+never received a response. Finally, move the removal of the scsi host from
+our global list to the end so that the host is easily locatable for
+debugging purposes during teardown.
+
+Cc: <stable@vger.kernel.org> # v2.6.12+
+Signed-off-by: Tyrel Datwyler <tyreld@linux.vnet.ibm.com>
+Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+---
+ drivers/scsi/ibmvscsi/ibmvscsi.c |   22 ++++++++++++++++------
+ 1 file changed, 16 insertions(+), 6 deletions(-)
+
+--- a/drivers/scsi/ibmvscsi/ibmvscsi.c
++++ b/drivers/scsi/ibmvscsi/ibmvscsi.c
+@@ -2296,17 +2296,27 @@ static int ibmvscsi_probe(struct vio_dev
+ static int ibmvscsi_remove(struct vio_dev *vdev)
+ {
+       struct ibmvscsi_host_data *hostdata = dev_get_drvdata(&vdev->dev);
+-      spin_lock(&ibmvscsi_driver_lock);
+-      list_del(&hostdata->host_list);
+-      spin_unlock(&ibmvscsi_driver_lock);
+-      unmap_persist_bufs(hostdata);
++      unsigned long flags;
++
++      srp_remove_host(hostdata->host);
++      scsi_remove_host(hostdata->host);
++
++      purge_requests(hostdata, DID_ERROR);
++
++      spin_lock_irqsave(hostdata->host->host_lock, flags);
+       release_event_pool(&hostdata->pool, hostdata);
++      spin_unlock_irqrestore(hostdata->host->host_lock, flags);
++
+       ibmvscsi_release_crq_queue(&hostdata->queue, hostdata,
+                                       max_events);
+       kthread_stop(hostdata->work_thread);
+-      srp_remove_host(hostdata->host);
+-      scsi_remove_host(hostdata->host);
++      unmap_persist_bufs(hostdata);
++
++      spin_lock(&ibmvscsi_driver_lock);
++      list_del(&hostdata->host_list);
++      spin_unlock(&ibmvscsi_driver_lock);
++
+       scsi_host_put(hostdata->host);
+       return 0;
diff --git a/queue-4.19/scsi-ibmvscsi-protect-ibmvscsi_head-from-concurrent-modificaiton.patch b/queue-4.19/scsi-ibmvscsi-protect-ibmvscsi_head-from-concurrent-modificaiton.patch
new file mode 100644 (file)
index 0000000..9d358fe
--- /dev/null
@@ -0,0 +1,57 @@
+From 7205981e045e752ccf96cf6ddd703a98c59d4339 Mon Sep 17 00:00:00 2001
+From: Tyrel Datwyler <tyreld@linux.vnet.ibm.com>
+Date: Wed, 20 Mar 2019 13:41:50 -0500
+Subject: scsi: ibmvscsi: Protect ibmvscsi_head from concurrent modificaiton
+
+From: Tyrel Datwyler <tyreld@linux.vnet.ibm.com>
+
+commit 7205981e045e752ccf96cf6ddd703a98c59d4339 upstream.
+
+For each ibmvscsi host created during a probe or destroyed during a remove
+we either add or remove that host to/from the global ibmvscsi_head
+list. This runs the risk of concurrent modification.
+
+This patch adds a simple spinlock around the list modification calls to
+prevent concurrent updates as is done similarly in the ibmvfc driver and
+ipr driver.
+
+Fixes: 32d6e4b6e4ea ("scsi: ibmvscsi: add vscsi hosts to global list_head")
+Cc: <stable@vger.kernel.org> # v4.10+
+Signed-off-by: Tyrel Datwyler <tyreld@linux.vnet.ibm.com>
+Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+---
+ drivers/scsi/ibmvscsi/ibmvscsi.c |    5 +++++
+ 1 file changed, 5 insertions(+)
+
+--- a/drivers/scsi/ibmvscsi/ibmvscsi.c
++++ b/drivers/scsi/ibmvscsi/ibmvscsi.c
+@@ -96,6 +96,7 @@ static int client_reserve = 1;
+ static char partition_name[96] = "UNKNOWN";
+ static unsigned int partition_number = -1;
+ static LIST_HEAD(ibmvscsi_head);
++static DEFINE_SPINLOCK(ibmvscsi_driver_lock);
+ static struct scsi_transport_template *ibmvscsi_transport_template;
+@@ -2271,7 +2272,9 @@ static int ibmvscsi_probe(struct vio_dev
+       }
+       dev_set_drvdata(&vdev->dev, hostdata);
++      spin_lock(&ibmvscsi_driver_lock);
+       list_add_tail(&hostdata->host_list, &ibmvscsi_head);
++      spin_unlock(&ibmvscsi_driver_lock);
+       return 0;
+       add_srp_port_failed:
+@@ -2293,7 +2296,9 @@ static int ibmvscsi_probe(struct vio_dev
+ static int ibmvscsi_remove(struct vio_dev *vdev)
+ {
+       struct ibmvscsi_host_data *hostdata = dev_get_drvdata(&vdev->dev);
++      spin_lock(&ibmvscsi_driver_lock);
+       list_del(&hostdata->host_list);
++      spin_unlock(&ibmvscsi_driver_lock);
+       unmap_persist_bufs(hostdata);
+       release_event_pool(&hostdata->pool, hostdata);
+       ibmvscsi_release_crq_queue(&hostdata->queue, hostdata,
index 35bda590e84815623b90e859659ae1e4c8f0c0da..b0f9cb020b7d2237dfc16ca6cc7eb53e10b9911d 100644 (file)
@@ -12,3 +12,11 @@ mips-loongson64-lemote-2f-add-irqf_no_suspend-to-cascade-irqaction.patch
 mips-ensure-elf-appended-dtb-is-relocated.patch
 mips-fix-kernel-crash-for-r6-in-jump-label-branch-function.patch
 powerpc-vdso64-fix-clock_monotonic-inconsistencies-across-y2038.patch
+scsi-ibmvscsi-protect-ibmvscsi_head-from-concurrent-modificaiton.patch
+scsi-ibmvscsi-fix-empty-event-pool-access-during-host-removal.patch
+futex-ensure-that-futex-address-is-aligned-in-handle_futex_death.patch
+cifs-allow-guest-mounts-to-work-for-smb3.11.patch
+perf-probe-fix-getting-the-kernel-map.patch
+objtool-move-objtool_file-struct-off-the-stack.patch
+irqchip-gic-v3-its-fix-comparison-logic-in-lpi_range_cmp.patch
+smb3-fix-smb3.1.1-guest-mounts-to-samba.patch
diff --git a/queue-4.19/smb3-fix-smb3.1.1-guest-mounts-to-samba.patch b/queue-4.19/smb3-fix-smb3.1.1-guest-mounts-to-samba.patch
new file mode 100644 (file)
index 0000000..2c484e7
--- /dev/null
@@ -0,0 +1,56 @@
+From 8c11a607d1d9cd6e7f01fd6b03923597fb0ef95a Mon Sep 17 00:00:00 2001
+From: Steve French <stfrench@microsoft.com>
+Date: Fri, 22 Mar 2019 22:31:17 -0500
+Subject: SMB3: Fix SMB3.1.1 guest mounts to Samba
+
+From: Steve French <stfrench@microsoft.com>
+
+commit 8c11a607d1d9cd6e7f01fd6b03923597fb0ef95a upstream.
+
+Workaround problem with Samba responses to SMB3.1.1
+null user (guest) mounts.  The server doesn't set the
+expected flag in the session setup response so we have
+to do a similar check to what is done in smb3_validate_negotiate
+where we also check if the user is a null user (but not sec=krb5
+since username might not be passed in on mount for Kerberos case).
+
+Note that the commit below tightened the conditions and forced signing
+for the SMB2-TreeConnect commands as per MS-SMB2.
+However, this should only apply to normal user sessions and not for
+cases where there is no user (even if server forgets to set the flag
+in the response) since we don't have anything useful to sign with.
+This is especially important now that the more secure SMB3.1.1 protocol
+is in the default dialect list.
+
+An earlier patch ("cifs: allow guest mounts to work for smb3.11") fixed
+the guest mounts to Windows.
+
+    Fixes: 6188f28bf608 ("Tree connect for SMB3.1.1 must be signed for non-encrypted shares")
+
+Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
+Reviewed-by: Paulo Alcantara <palcantara@suse.de>
+CC: Stable <stable@vger.kernel.org>
+Signed-off-by: Steve French <stfrench@microsoft.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+---
+ fs/cifs/smb2pdu.c |    5 ++++-
+ 1 file changed, 4 insertions(+), 1 deletion(-)
+
+--- a/fs/cifs/smb2pdu.c
++++ b/fs/cifs/smb2pdu.c
+@@ -1503,10 +1503,13 @@ SMB2_tcon(const unsigned int xid, struct
+       /*
+        * 3.11 tcon req must be signed if not encrypted. See MS-SMB2 3.2.4.1.1
+        * unless it is guest or anonymous user. See MS-SMB2 3.2.5.3.1
++       * (Samba servers don't always set the flag so also check if null user)
+        */
+       if ((ses->server->dialect == SMB311_PROT_ID) &&
+           !smb3_encryption_required(tcon) &&
+-          !(ses->session_flags & (SMB2_SESSION_FLAG_IS_GUEST|SMB2_SESSION_FLAG_IS_NULL)))
++          !(ses->session_flags &
++                  (SMB2_SESSION_FLAG_IS_GUEST|SMB2_SESSION_FLAG_IS_NULL)) &&
++          ((ses->user_name != NULL) || (ses->sectype == Kerberos)))
+               req->sync_hdr.Flags |= SMB2_FLAGS_SIGNED;
+       memset(&rqst, 0, sizeof(struct smb_rqst));