CVE-2022-49567

What it is

In the Linux kernel, the following vulnerability has been resolved: mm/mempolicy: fix uninit-value in mpol_rebind_policy() 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().

At a glance

Exploitability

Can be exploited locally on the machine with a low-privilege account. High risk of service disruption.

Exploit odds

0.3% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2025-02-26 07:01 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-06-17 05:18 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: no, CISA does not list it.
• Exploit odds: 0.3% in the next 30 days (EPSS).
• Severity: 5.5 MEDIUM (CVSS).
• Fix: a patch or advisory is linked.

Details

Published

2025-02-26 07:01 UTC

Last modified

2026-06-17 05:18 UTC

Exploit probability

0.3% · EPSS, next 30 days

Weakness

CWE-908

Record status

Modified

Affected

• Linux Kernel < 4.9.325
• Linux Kernel < 4.14.290
• Linux Kernel < 4.19.254
• Linux Kernel < 5.4.208
• Linux Kernel < 5.10.134
• Linux Kernel < 5.15.58
• Linux Kernel < 5.18.15

Attack profile CVSS 3.1 · 5.5

Attack vector

Local

Complexity

Low

Privileges needed

Low

User interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

None

Availability

High

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2022-49567.md and follow it. Check whether this project is affected by CVE-2022-49567. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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