CVE-2022-50240
HighIn the Linux kernel, the following vulnerability has been resolved: android: binder: stop saving a pointer to the VMA Do not record a pointer to a VMA outside of the mmap_lock for later use. This is unsafe and there are a number of failure paths *after* the recorded VMA pointer may be freed during setup. There is no callback to the driver to clear the saved pointer from generic mm code. Furthermore, the VMA pointer may become stale if any number of VMA operations end up freeing the VMA so saving it was fragile to being with. Instead, change the binder_alloc struct to record the start address of the VMA and use vma_lookup() to get the vma when needed. Add lockdep mmap_lock checks on updates to the vma pointer to ensure the lock is held and depend on that lock for synchronization of readers and writers - which was already the case anyways, so the smp_wmb()/smp_rmb() was not necessary. [[email protected]: fix drivers/android/binder_alloc_selftest.c]
CVSS 3.1 score
7.8
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Weakness type
CWE-416CVE-2022-50240 is a Use After Free vulnerability
What is Use After Free?
The product references memory after it has been freed, which may cause it to crash, use unexpected values, or execute code. Learn more on MITRE CWE
Affected versions
Linux kernel versions
4.20
and later are affected. Fixed in
5.4.224,
5.10.154,
5.15.61,
5.18.18,
5.19.2,
6.0
and their respective stable series.
References
The following references provide additional information about CVE-2022-50240 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/015ac18be7de25d17d6e5f1643cb3b60bfbe859e
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PatchKernel patch commithttps://git.kernel.org/stable/c/1ec3f76a436d750fd5023caec5da0494fc2870d2
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PatchKernel patch commithttps://git.kernel.org/stable/c/27a594bc7a7c8238d239e3cdbcf2edfa3bbe9a1b
Frequently asked questions
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What is CVE-2022-50240?
CVE-2022-50240 is a High severity Linux kernel vulnerability with a CVSS score of 7.8 out of 10 , classified as an Use After Free flaw (CWE-416) . It affects Linux kernel versions from 4.20 onward and has been patched in 5.4.224, 5.10.154, 5.15.61 and others. CVE-2022-50240 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-2022-50240?
CVE-2022-50240 has a CVSS score of 7.8 out of 10, rated High severity (CVSS 3.1). The vector string is
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. -
Is there a patch available for CVE-2022-50240?
Yes — CVE-2022-50240 has been patched. Fixed versions include 5.4.224, 5.10.154, 5.15.61 and others. If you are running Linux kernel 4.20 or later up to the fix versions, apply the relevant patch for your kernel branch.
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Is CVE-2022-50240 actively exploited?
No — CVE-2022-50240 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 Use After Free (CWE-416)?
The product references memory after it has been freed, which may cause it to crash, use unexpected values, or execute code. View CWE-416 on MITRE CWE →