Bug 2425197 (CVE-2022-50746)

Summary: CVE-2022-50746 kernel: erofs: validate the extent length for uncompressed pclusters
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
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OS: Linux   
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Description OSIDB Bzimport 2025-12-24 14:10:13 UTC 
In the Linux kernel, the following vulnerability has been resolved:

erofs: validate the extent length for uncompressed pclusters

syzkaller reported a KASAN use-after-free:
https://syzkaller.appspot.com/bug?extid=2ae90e873e97f1faf6f2

The referenced fuzzed image actually has two issues:
 - m_pa == 0 as a non-inlined pcluster;
 - The logical length is longer than its physical length.

The first issue has already been addressed.  This patch addresses
the second issue by checking the extent length validity.
Comment 1 Alexander B 2025-12-24 19:23:48 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2025122450-CVE-2022-50746-7cbf@gregkh/T