CVE-2026-43362

HIGH

smb: client: fix in-place encryption corruption in SMB2_write()

Title source: cna
STIX 2.1

Description

In the Linux kernel, the following vulnerability has been resolved: smb: client: fix in-place encryption corruption in SMB2_write() SMB2_write() places write payload in iov[1..n] as part of rq_iov. smb3_init_transform_rq() pointer-shares rq_iov, so crypt_message() encrypts iov[1] in-place, replacing the original plaintext with ciphertext. On a replayable error, the retry sends the same iov[1] which now contains ciphertext instead of the original data, resulting in corruption. The corruption is most likely to be observed when connections are unstable, as reconnects trigger write retries that re-send the already-encrypted data. This affects SFU mknod, MF symlinks, etc. On kernels before 6.10 (prior to the netfs conversion), sync writes also used this path and were similarly affected. The async write path wasn't unaffected as it uses rq_iter which gets deep-copied. Fix by moving the write payload into rq_iter via iov_iter_kvec(), so smb3_init_transform_rq() deep-copies it before encryption.

Scores

CVSS v3 8.1
EPSS 0.0022
EPSS Percentile 12.1%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:H

Details

CWE
CWE-787
Status published
Products (23)
linux/Kernel 4.11.0 - 6.6.130linux
linux/Kernel 6.13.0 - 6.18.19linux
linux/Kernel 6.19.0 - 6.19.9linux
linux/Kernel 6.7.0 - 6.12.78linux
Linux/Linux < 4.11
Linux/Linux 026e93dc0a3eefb0be060bcb9ecd8d7a7fd5c398 - 438e77435aee2894d5edf90be5c87004a57f6258
Linux/Linux 026e93dc0a3eefb0be060bcb9ecd8d7a7fd5c398 - 52327268224fb9ccc7ecfbbdfdfff54b6e93c518
Linux/Linux 026e93dc0a3eefb0be060bcb9ecd8d7a7fd5c398 - 92e64f1852f455f57d0850989e57c30d7fac7d95
Linux/Linux 026e93dc0a3eefb0be060bcb9ecd8d7a7fd5c398 - aea5e37388a080361110ab5790f57ae0af383650
Linux/Linux 026e93dc0a3eefb0be060bcb9ecd8d7a7fd5c398 - d78840a6a38d312dc1a51a65317bb67e46f0b929
... and 13 more
Published May 08, 2026
Tracked Since May 08, 2026