From: Greg Kroah-Hartman Date: Sun, 24 Jul 2022 15:49:56 +0000 (+0200) Subject: 4.9-stable patches X-Git-Tag: v5.10.133~18 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=c1760561ccf2adb20c5dcdb924c875b5c194411f;p=thirdparty%2Fkernel%2Fstable-queue.git 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 index 00000000000..2906cbcbfc3 --- /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 +Date: Thu, 19 May 2022 14:08:54 -0700 +Subject: mm/mempolicy: fix uninit-value in mpol_rebind_policy() + +From: Wang Cheng + +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 +Reported-by: +Tested-by: +Cc: David Rientjes +Cc: Vlastimil Babka +Signed-off-by: Andrew Morton +Signed-off-by: Greg Kroah-Hartman +--- + 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 9b406a6f9ec..8cecf2e0354 100644 --- 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