CVE-2022-49256
MediumIn 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
CVSS 3.1 score
5.5
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Weakness type
CWE-401CVE-2022-49256 is a Memory Leak vulnerability
What is Memory Leak?
The product does not release memory after use, causing gradual resource exhaustion. Learn more on MITRE CWE
Affected versions
Linux kernel versions
5.8
and later are affected. Fixed in
5.10.110,
5.15.33,
5.16.19,
5.17.2,
5.18
and their respective stable series.
References
The following references provide additional information about CVE-2022-49256 including vendor advisories, patch commits, exploit details, and third-party analysis. Links are sourced from the NIST NVD database.
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PatchKernel patch commithttps://git.kernel.org/stable/c/31824613a42aacdcbeb325bf07a1c8247a11ebe2
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PatchKernel patch commithttps://git.kernel.org/stable/c/3d8dcf278b1ee1eff1e90be848fa2237db4c07a7
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PatchKernel patch commithttps://git.kernel.org/stable/c/7e8c9b0df07a77f0d072603b8ced2677e30e1893
Frequently asked questions
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What is CVE-2022-49256?
CVE-2022-49256 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10 , classified as a Memory Leak flaw (CWE-401) . It affects Linux kernel versions from 5.8 onward and has been patched in 5.10.110, 5.15.33, 5.16.19 and others. CVE-2022-49256 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
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What is the CVSS score for CVE-2022-49256?
CVE-2022-49256 has a CVSS score of 5.5 out of 10, rated Medium severity (CVSS 3.1). The vector string is
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H. -
Is there a patch available for CVE-2022-49256?
Yes — CVE-2022-49256 has been patched. Fixed versions include 5.10.110, 5.15.33, 5.16.19 and others. If you are running Linux kernel 5.8 or later up to the fix versions, apply the relevant patch for your kernel branch.
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Is CVE-2022-49256 actively exploited?
No — CVE-2022-49256 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.
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What is Memory Leak (CWE-401)?
The product does not release memory after use, causing gradual resource exhaustion. View CWE-401 on MITRE CWE →