Linux vulnerability

What happened

In the Linux kernel, the following vulnerability has been resolved: fs/smb/client: fix out-of-bounds read in cifs_sanitize_prepath When cifs_sanitize_prepath is called with an empty string or a string containing only delimiters (e.g., "/"), the current logic attempts to check *(cursor2 - 1) before cursor2 has advanced. This results in an out-of-bounds read. This patch adds an early exit check after stripping prepended delimiters. If no path content remains, the function returns NULL. The bug was identified via manual audit and verified using a standalone test case compiled with AddressSanitizer, which triggered a SEGV on affected inputs.

Affected versions

Linux: c63433a09d6ae4c226fcbc66da4c58fc189fd746 through before a2ba20c17de8eb028f96b1d85f119d3d25655bd9 (git); a31080899d5fdafcccf7f39dd214a814a2c82626 through before fbced33599653471b4581dfe1abc7b467031f126 (git); a31080899d5fdafcccf7f39dd214a814a2c82626 through before 5d4fe469fe7dbff7d874c196bb680a82f2625d95 (git); a31080899d5fdafcccf7f39dd214a814a2c82626 through before 2d29214448ec0f4e7e18bb1c14dd4a6c07f1c439 (git); a31080899d5fdafcccf7f39dd214a814a2c82626 through before 86f9c23e0814cfdffda9eedf0c591c51ba209010 (git); a31080899d5fdafcccf7f39dd214a814a2c82626 through before 49b1ce6d7cfb6c5a49f68bf5ccfcfb6ba14e63c3 (git); a31080899d5fdafcccf7f39dd214a814a2c82626 through before 78ec5bf2f589ec7fd8f169394bfeca541b077317 (git); 5.15.11 through before 5.15.209 (semver); 5.16 Fixed: See vendor advisory.

Why it matters

Review the vendor advisory and exposure of the affected product to determine operational impact.

Detection & mitigation

• Apply vendor-provided updates or mitigations.
• Review affected product exposure and access logs.