CVE-2022-49401
Published: 26 February 2025
Summary
CVE-2022-49401 is a high-severity Out-of-bounds Read (CWE-125) vulnerability in Linux Linux Kernel. Its CVSS base score is 7.1 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Application or System Exploitation (T1499.004); ranked at the 36.4th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified are NIST 800-53 SI-2 (Flaw Remediation) and RA-5 (Vulnerability Monitoring and Scanning).
Deeper analysis
CVE-2022-49401 is a vulnerability in the Linux kernel's memory management subsystem, specifically in the mm/page_owner.c component. The issue arises from the use of strlcpy() to copy the current process's comm[] field (current->comm[]), which is not guaranteed to be null-terminated. This leads strlcpy() to invoke strlen() on the source buffer, potentially causing an out-of-bounds read and buffer overflow, as detected by syzbot. The flaw triggers a kernel BUG in __fortify_strlen during page allocation operations, such as in __set_page_owner_handle(), and is classified under CWE-125 (Out-of-bounds Read) with a CVSS v3.1 base score of 7.1 (AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H).
A local attacker with low privileges (PR:L) can exploit this vulnerability by triggering memory allocation paths, such as slab allocations via alloc_pages() and related functions like get_page_from_freelist() or dst_alloc(). This results in a kernel panic due to the fortify_panic() invocation, enabling a denial-of-service (A:H). The high confidentiality impact (C:H) stems from potential information disclosure during the out-of-bounds access before the crash.
Kernel stable patches address the issue by replacing strlcpy() with strscpy(), which safely copies without relying on strlen() for non-null-terminated sources. Relevant commits include 5cd9900a1ac8b0a4ff3cd97d4d77b7711be435bf and cd8c1fd8cdd14158f2d8bea2d1bfe8015dccfa3a, available via git.kernel.org/stable.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2022-54828
Vulnerability details
In the Linux kernel, the following vulnerability has been resolved: mm/page_owner: use strscpy() instead of strlcpy() current->comm[] is not a string (no guarantee for a zero byte in it). strlcpy(s1, s2, l) is calling strlen(s2), potentially causing out-of-bound access, as…
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reported by syzbot: detected buffer overflow in __fortify_strlen ------------[ cut here ]------------ kernel BUG at lib/string_helpers.c:980! invalid opcode: 0000 [#1] PREEMPT SMP KASAN CPU: 0 PID: 4087 Comm: dhcpcd-run-hooks Not tainted 5.18.0-rc3-syzkaller-01537-g20b87e7c29df #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:fortify_panic+0x18/0x1a lib/string_helpers.c:980 Code: 8c e8 c5 ba e1 fa e9 23 0f bf fa e8 0b 5d 8c f8 eb db 55 48 89 fd e8 e0 49 40 f8 48 89 ee 48 c7 c7 80 f5 26 8a e8 99 09 f1 ff <0f> 0b e8 ca 49 40 f8 48 8b 54 24 18 4c 89 f1 48 c7 c7 00 00 27 8a RSP: 0018:ffffc900000074a8 EFLAGS: 00010286 RAX: 000000000000002c RBX: ffff88801226b728 RCX: 0000000000000000 RDX: ffff8880198e0000 RSI: ffffffff81600458 RDI: fffff52000000e87 RBP: ffffffff89da2aa0 R08: 000000000000002c R09: 0000000000000000 R10: ffffffff815fae2e R11: 0000000000000000 R12: ffff88801226b700 R13: ffff8880198e0830 R14: 0000000000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f5876ad6ff8 CR3: 000000001a48c000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600 Call Trace: <IRQ> __fortify_strlen include/linux/fortify-string.h:128 [inline] strlcpy include/linux/fortify-string.h:143 [inline] __set_page_owner_handle+0x2b1/0x3e0 mm/page_owner.c:171 __set_page_owner+0x3e/0x50 mm/page_owner.c:190 prep_new_page mm/page_alloc.c:2441 [inline] get_page_from_freelist+0xba2/0x3e00 mm/page_alloc.c:4182 __alloc_pages+0x1b2/0x500 mm/page_alloc.c:5408 alloc_pages+0x1aa/0x310 mm/mempolicy.c:2272 alloc_slab_page mm/slub.c:1799 [inline] allocate_slab+0x26c/0x3c0 mm/slub.c:1944 new_slab mm/slub.c:2004 [inline] ___slab_alloc+0x8df/0xf20 mm/slub.c:3005 __slab_alloc.constprop.0+0x4d/0xa0 mm/slub.c:3092 slab_alloc_node mm/slub.c:3183 [inline] slab_alloc mm/slub.c:3225 [inline] __kmem_cache_alloc_lru mm/slub.c:3232 [inline] kmem_cache_alloc+0x360/0x3b0 mm/slub.c:3242 dst_alloc+0x146/0x1f0 net/core/dst.c:92
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
Local kernel OOB read triggers fortify_panic during page allocation, directly enabling system exploitation for DoS (kernel panic) with secondary info disclosure.
CVEs Like This One
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
Directly requires timely remediation of the kernel flaw by patching the unsafe strlcpy() usage in mm/page_owner.c with strscpy().
Enables identification of systems running vulnerable kernel versions affected by CVE-2022-49401 through vulnerability scanning.
Provides memory protections that mitigate or detect out-of-bounds reads triggered by strlen() on non-null-terminated current->comm[] during page allocation.