In the Linux kernel, the following vulnerability has been resolved:
ksmbd: fix out-of-bounds write in smb2_get_ea() EA alignment
smb2_get_ea() applies 4-byte alignment padding via memset() after
writing each EA entry. The bounds check on buf_free_len is performed
before the value memcpy, but the alignment memset fires unconditionally
afterward with no check on remaining space.
When the EA value exactly fills the remaining buffer (buf_free_len == 0
after value subtraction), the alignment memset writes 1-3 NUL bytes
past the buf_free_len boundary. In compound requests where the response
buffer is shared across commands, the first command (e.g., READ) can
consume most of the buffer, leaving a tight remainder for the QUERY_INFO
EA response. The alignment memset then overwrites past the physical
kvmalloc allocation into adjacent kernel heap memory.
Add a bounds check before the alignment memset to ensure buf_free_len
can accommodate the padding bytes.
This is the same bug pattern fixed by commit beef2634f81f ("ksmbd: fix
potencial OOB in get_file_all_info() for compound requests") and
commit fda9522ed6af ("ksmbd: fix OOB write in QUERY_INFO for compound
requests"), both of which added bounds checks before unconditional
writes in QUERY_INFO response handlers.
Published: 2026-05-01
CVSS: 9.8
CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Download CVE-2026-31705 POC (Proof-of-Concept) here:
Tip: Download official Tor Browser at https://www.torproject.org/download/ to access .onion links.
https://hokyo.gr/poc-333-cve-2026-3359/
https://hokyo.gr/poc-592-cve-2026-7927/
https://hokyo.gr/poc-746-cve-2026-42214/
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