CVE-2022-49256
CVE-2022-49256 is a medium-severity vulnerability in Linux Linux Kernel with a CVSS 3.x base score of 5.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-401.
Key facts
- Severity: Medium (CVSS 3.x base score 5.5)
- EPSS exploit prediction: 0% (16th percentile)
- Actively exploited: Not listed in CISA KEV
- EU (EUVD) id: EUVD-2022-54970
- Weakness: CWE-401
- Affected product: Linux Linux Kernel
- Published:
- Last modified:
Description
In the Linux kernel, the following vulnerability has been resolved: watch_queue: Actually free the watch free_watch() does everything barring actually freeing the watch object. Fix this by adding the missing kfree. kmemleak produces a report something like the following. Note that as an address can be seen in the first word, the watch would appear to have gone through call_rcu(). BUG: memory leak unreferenced object 0xffff88810ce4a200 (size 96): comm "syz-executor352", pid 3605, jiffies 4294947473 (age 13.720s) hex dump (first 32 bytes): e0 82 48 0d 81 88 ff ff 00 00 00 00 00 00 00 00 ..H............. 80 a2 e4 0c 81 88 ff ff 00 00 00 00 00 00 00 00 ................ backtrace: [<ffffffff8214e6cc>] kmalloc include/linux/slab.h:581 [inline] [<ffffffff8214e6cc>] kzalloc include/linux/slab.h:714 [inline] [<ffffffff8214e6cc>] keyctl_watch_key+0xec/0x2e0 security/keys/keyctl.c:1800 [<ffffffff8214ec84>] __do_sys_keyctl+0x3c4/0x490 security/keys/keyctl.c:2016 [<ffffffff84493a25>] do_syscall_x64 arch/x86/entry/common.c:50 [inline] [<ffffffff84493a25>] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 [<ffffffff84600068>] entry_SYSCALL_64_after_hwframe+0x44/0xae
Frequently asked questions
- What is CVE-2022-49256?
- In the Linux kernel, the following vulnerability has been resolved: watch_queue: Actually free the watch free_watch() does everything barring actually freeing the watch object. Fix this by adding the missing kfree. kmemleak produces a report something like the following. Note that as an address can be seen in the first word, the watch would appear to have gone through call_rcu(). BUG: memory leak unreferenced object 0xffff88810ce4a200 (size 96): comm "syz-executor352", pid 3605, jiffies 4294947473 (age 13.720s) hex dump (first 32 bytes): e0 82 48 0d 81 88 ff ff 00 00 00 00 00 00 00 00 ..H............. 80 a2 e4 0c 81 88 ff ff 00 00 00 00 00 00 00 00 ................ backtrace: [<ffffffff8214e6cc>] kmalloc include/linux/slab.h:581 [inline] [<ffffffff8214e6cc>] kzalloc include/linux/slab.h:714 [inline] [<ffffffff8214e6cc>] keyctl_watch_key+0xec/0x2e0 security/keys/keyctl.c:1800 [<ffffffff8214ec84>] __do_sys_keyctl+0x3c4/0x490 security/keys/keyctl.c:2016 [<ffffffff84493a25>] do_syscall_x64 arch/x86/entry/common.c:50 [inline] [<ffffffff84493a25>] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 [<ffffffff84600068>] entry_SYSCALL_64_after_hwframe+0x44/0xae
- How severe is CVE-2022-49256?
- CVE-2022-49256 has a CVSS 3.x base score of 5.5, rated medium severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
- Is CVE-2022-49256 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (16th percentile), an estimate of the probability of exploitation in the next 30 days.
- What products are affected by CVE-2022-49256?
- CVE-2022-49256 affects Linux Linux Kernel. See the affected-products list for the exact vulnerable versions.
- How do I fix CVE-2022-49256?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
- Does CVE-2022-49256 have an EU (EUVD) identifier?
- Yes. CVE-2022-49256 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2022-54970.
- When was CVE-2022-49256 published?
- CVE-2022-49256 was published on 2025-02-26 and last updated on 2026-06-17.
References
- https://git.kernel.org/stable/c/31824613a42aacdcbeb325bf07a1c8247a11ebe2
- https://git.kernel.org/stable/c/3d8dcf278b1ee1eff1e90be848fa2237db4c07a7
- https://git.kernel.org/stable/c/7e8c9b0df07a77f0d072603b8ced2677e30e1893
- https://git.kernel.org/stable/c/9d92be1a09fbb3dd65600dbfe7eedb40e7228e4b
- https://git.kernel.org/stable/c/f69aecb49968e14196366bbe896eab0a904229f5
Affected products (1)
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
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