4.9-stable patches

added patches:
	mm-mempolicy-fix-uninit-value-in-mpol_rebind_policy.patch

diff --git a/queue-4.9/mm-mempolicy-fix-uninit-value-in-mpol_rebind_policy.patch b/queue-4.9/mm-mempolicy-fix-uninit-value-in-mpol_rebind_policy.patch
new file mode 100644 (file)
index 0000000..2906cbc
--- /dev/null
+++ b/queue-4.9/mm-mempolicy-fix-uninit-value-in-mpol_rebind_policy.patch
@@ -0,0 +1,106 @@
+From 018160ad314d75b1409129b2247b614a9f35894c Mon Sep 17 00:00:00 2001
+From: Wang Cheng <wanngchenng@gmail.com>
+Date: Thu, 19 May 2022 14:08:54 -0700
+Subject: mm/mempolicy: fix uninit-value in mpol_rebind_policy()
+
+From: Wang Cheng <wanngchenng@gmail.com>
+
+commit 018160ad314d75b1409129b2247b614a9f35894c upstream.
+
+mpol_set_nodemask()(mm/mempolicy.c) does not set up nodemask when
+pol->mode is MPOL_LOCAL.  Check pol->mode before access
+pol->w.cpuset_mems_allowed in mpol_rebind_policy()(mm/mempolicy.c).
+
+BUG: KMSAN: uninit-value in mpol_rebind_policy mm/mempolicy.c:352 [inline]
+BUG: KMSAN: uninit-value in mpol_rebind_task+0x2ac/0x2c0 mm/mempolicy.c:368
+ mpol_rebind_policy mm/mempolicy.c:352 [inline]
+ mpol_rebind_task+0x2ac/0x2c0 mm/mempolicy.c:368
+ cpuset_change_task_nodemask kernel/cgroup/cpuset.c:1711 [inline]
+ cpuset_attach+0x787/0x15e0 kernel/cgroup/cpuset.c:2278
+ cgroup_migrate_execute+0x1023/0x1d20 kernel/cgroup/cgroup.c:2515
+ cgroup_migrate kernel/cgroup/cgroup.c:2771 [inline]
+ cgroup_attach_task+0x540/0x8b0 kernel/cgroup/cgroup.c:2804
+ __cgroup1_procs_write+0x5cc/0x7a0 kernel/cgroup/cgroup-v1.c:520
+ cgroup1_tasks_write+0x94/0xb0 kernel/cgroup/cgroup-v1.c:539
+ cgroup_file_write+0x4c2/0x9e0 kernel/cgroup/cgroup.c:3852
+ kernfs_fop_write_iter+0x66a/0x9f0 fs/kernfs/file.c:296
+ call_write_iter include/linux/fs.h:2162 [inline]
+ new_sync_write fs/read_write.c:503 [inline]
+ vfs_write+0x1318/0x2030 fs/read_write.c:590
+ ksys_write+0x28b/0x510 fs/read_write.c:643
+ __do_sys_write fs/read_write.c:655 [inline]
+ __se_sys_write fs/read_write.c:652 [inline]
+ __x64_sys_write+0xdb/0x120 fs/read_write.c:652
+ do_syscall_x64 arch/x86/entry/common.c:51 [inline]
+ do_syscall_64+0x54/0xd0 arch/x86/entry/common.c:82
+ entry_SYSCALL_64_after_hwframe+0x44/0xae
+
+Uninit was created at:
+ slab_post_alloc_hook mm/slab.h:524 [inline]
+ slab_alloc_node mm/slub.c:3251 [inline]
+ slab_alloc mm/slub.c:3259 [inline]
+ kmem_cache_alloc+0x902/0x11c0 mm/slub.c:3264
+ mpol_new mm/mempolicy.c:293 [inline]
+ do_set_mempolicy+0x421/0xb70 mm/mempolicy.c:853
+ kernel_set_mempolicy mm/mempolicy.c:1504 [inline]
+ __do_sys_set_mempolicy mm/mempolicy.c:1510 [inline]
+ __se_sys_set_mempolicy+0x44c/0xb60 mm/mempolicy.c:1507
+ __x64_sys_set_mempolicy+0xd8/0x110 mm/mempolicy.c:1507
+ do_syscall_x64 arch/x86/entry/common.c:51 [inline]
+ do_syscall_64+0x54/0xd0 arch/x86/entry/common.c:82
+ entry_SYSCALL_64_after_hwframe+0x44/0xae
+
+KMSAN: uninit-value in mpol_rebind_task (2)
+https://syzkaller.appspot.com/bug?id=d6eb90f952c2a5de9ea718a1b873c55cb13b59dc
+
+This patch seems to fix below bug too.
+KMSAN: uninit-value in mpol_rebind_mm (2)
+https://syzkaller.appspot.com/bug?id=f2fecd0d7013f54ec4162f60743a2b28df40926b
+
+The uninit-value is pol->w.cpuset_mems_allowed in mpol_rebind_policy().
+When syzkaller reproducer runs to the beginning of mpol_new(),
+
+           mpol_new() mm/mempolicy.c
+         do_mbind() mm/mempolicy.c
+       kernel_mbind() mm/mempolicy.c
+
+`mode` is 1(MPOL_PREFERRED), nodes_empty(*nodes) is `true` and `flags`
+is 0. Then
+
+       mode = MPOL_LOCAL;
+       ...
+       policy->mode = mode;
+       policy->flags = flags;
+
+will be executed. So in mpol_set_nodemask(),
+
+           mpol_set_nodemask() mm/mempolicy.c
+         do_mbind()
+       kernel_mbind()
+
+pol->mode is 4 (MPOL_LOCAL), that `nodemask` in `pol` is not initialized,
+which will be accessed in mpol_rebind_policy().
+
+Link: https://lkml.kernel.org/r/20220512123428.fq3wofedp6oiotd4@ppc.localdomain
+Signed-off-by: Wang Cheng <wanngchenng@gmail.com>
+Reported-by: <syzbot+217f792c92599518a2ab@syzkaller.appspotmail.com>
+Tested-by: <syzbot+217f792c92599518a2ab@syzkaller.appspotmail.com>
+Cc: David Rientjes <rientjes@google.com>
+Cc: Vlastimil Babka <vbabka@suse.cz>
+Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ mm/mempolicy.c |    2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+--- a/mm/mempolicy.c
++++ b/mm/mempolicy.c
+@@ -396,7 +396,7 @@ static void mpol_rebind_preferred(struct
+ static void mpol_rebind_policy(struct mempolicy *pol, const nodemask_t *newmask,
+                               enum mpol_rebind_step step)
+ {
+-      if (!pol)
++      if (!pol || pol->mode == MPOL_LOCAL)
+               return;
+       if (!mpol_store_user_nodemask(pol) && step == MPOL_REBIND_ONCE &&
+           nodes_equal(pol->w.cpuset_mems_allowed, *newmask))

diff --git a/queue-4.9/series b/queue-4.9/series
index 9b406a6f9ec4e195edab47855c35555d3d71fa66..8cecf2e0354a18d220f0795be61345cbeae82753 100644 (file)
--- a/queue-4.9/series
+++ b/queue-4.9/series
@@ -15,3 +15,4 @@ igmp-fix-a-data-race-around-sysctl_igmp_max_membersh.patch
 tcp-fix-a-data-race-around-sysctl_tcp_notsent_lowat.patch
 be2net-fix-buffer-overflow-in-be_get_module_eeprom.patch
 revert-revert-char-random-silence-a-lockdep-splat-with-printk.patch
+mm-mempolicy-fix-uninit-value-in-mpol_rebind_policy.patch