Description
In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix OOB write in QUERY_INFO for compound requests When a compound request such as READ + QUERY_INFO(Security) is received, and the first command (READ) consumes most of the response buffer, ksmbd could write beyond the allocated buffer while building a security descriptor. The root cause was that smb2_get_info_sec() checked buffer space using ppntsd_size from xattr, while build_sec_desc() often synthesized a significantly larger descriptor from POSIX ACLs. This patch introduces smb_acl_sec_desc_scratch_len() to accurately compute the final descriptor size beforehand, performs proper buffer checking with smb2_calc_max_out_buf_len(), and uses exact-sized allocation + iov pinning.
Affected products
linux: linux kernel
References6
- git.kernel.org/stable/c/075ea208c648cc2bcd616295b711d3637c61de45 Patch
- git.kernel.org/stable/c/515c2daab46021221bdf406bef19bc90a44ec617 Patch
- git.kernel.org/stable/c/d48c64fb80ad78b3dd29fb7d79b6ec7bd72bfc09 Patch
- git.kernel.org/stable/c/fda9522ed6afaec45cabc198d8492270c394c7bc Patch
- git.kernel.org/stable/c/533f84264e28c54a79257ea87d2f94a0fcc9a611
- git.kernel.org/stable/c/850452af77f55d185f9445e1f7a1db53c5e4aad4
Metrics
- CVSS 3.1
-
8.8
HIGH
Score source: CNA
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H - EPSS — exploit probability
- 1% percentile: 46 · as of 13 November 2026
- CWE
- CWE-787
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