CVE-2026-98171

Summary

In the Linux kernel, the following vulnerability has been resolved:

smb: client: fix next_buffer UAF and NextCommand bounds in compound PDUs

Fix several related bounds checking and pointer lifecycle issues in receive_encrypted_standard()'s handling of compound encrypted frames:

  • Clear next_buffer after assigning it to server->bigbuf. A stale next_buffer pointer can lead to a use-after-free on subsequent error paths.
  • Update pdu_length to the decrypted plaintext size (buf_size). Using the pre-decryption length allows NextCommand to point into stale ciphertext residue.
  • Reject next_cmd values smaller than MID_HEADER_SIZE(server).
  • Fix an integer overflow in the upper bound check by verifying pdu_length - next_cmd < MID_HEADER_SIZE(server), ensuring the trailing slice is large enough for a header.

Affected Software

VendorProductVersion RangeStatus
LinuxLinuxb24df3e30cbf48255db866720fb71f14bf9d2f39 < 72eaef1f37a3b6bec11c342736834dc3707be3e4affected
LinuxLinuxb24df3e30cbf48255db866720fb71f14bf9d2f39 < 491e33144dee872cffda207f6fcb09260728f803affected
LinuxLinuxb24df3e30cbf48255db866720fb71f14bf9d2f39 < 8749946579708ea0d339034bb7f423a67dbe89cfaffected
LinuxLinuxb24df3e30cbf48255db866720fb71f14bf9d2f39 < 96c436e4b010711452b2872558938f4ef276492aaffected
LinuxLinuxb24df3e30cbf48255db866720fb71f14bf9d2f39 < 858d5ac22cb889266993e7670f9f0c4f4aeedd78affected
LinuxLinuxb24df3e30cbf48255db866720fb71f14bf9d2f39 < 05762c5bc1cfdcac36747994fde2c04387a457f1affected
LinuxLinux4.19affected
LinuxLinux0 < 4.19unaffected
LinuxLinux6.1.189 <= 6.1.*unaffected
LinuxLinux6.6.158 <= 6.6.*unaffected
LinuxLinux6.12.112 <= 6.12.*unaffected
LinuxLinux6.18.54 <= 6.18.*unaffected
LinuxLinux7.2.8 <= 7.2.*unaffected
LinuxLinux7.3-rc4 <= *unaffected

Weaknesses

References