CVE-2026-64383

smb: client: fix double-free in SMB2_flush() replay

State: Published
Severity: 9.8 Critical
Published: Jul 25, 2026
Updated: Oct 19, 2026
Reserved: Jul 19, 2026

Description

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

smb: client: fix double-free in SMB2_flush() replay

SMB2_flush() keeps its response buffer bookkeeping across replay attempts. If a replayable flush response is received and the retry then fails before cifs_send_recv() stores a replacement response, flush_exit will free the stale response pointer a second time.

Reinitialize resp_buftype and rsp_iov at the top of the replay loop so cleanup only acts on response state produced by the current attempt. This fixes a double-free without changing replay handling for successful requests.

Scores

CVSS	Score	Vector	Source
3.1	9.8 Critical	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H	Linux

Weaknesses

CWE-415 Double Free

Affected Products

Product	Versions
LinuxLinux	433042a91f9373241307725b52de573933ffedbf to before 6e27f40b682a5e42a2daae3ce6d96f0e0e16dedbAffected 4f1fffa2376922f3d1d506e49c0fd445b023a28e to before 878757163eea684750107a31ea134c103863515dAffected 4f1fffa2376922f3d1d506e49c0fd445b023a28e to before 3407240cde132a4b72d6429a2625a09a2f78adafAffected 4f1fffa2376922f3d1d506e49c0fd445b023a28e to before 013a9a3da46c5dabcf18f65ea6a47874ba12a15dAffected 4f1fffa2376922f3d1d506e49c0fd445b023a28e to before 4be31c943a3a27a5a0251dbb8f5cb89059ec3d5aAffected 6.6.32 to before 6.6.145Affected
LinuxLinux	6.8Affected before 6.8Not affected 6.6.145 through 6.6.Not affected 6.12.96 through 6.12.Not affected 6.18.39 through 6.18.Not affected 7.1.4 through 7.1.Not affected 7.2 and laterNot affected

Product

Versions

LinuxLinux

433042a91f9373241307725b52de573933ffedbf to before 6e27f40b682a5e42a2daae3ce6d96f0e0e16dedbAffected
4f1fffa2376922f3d1d506e49c0fd445b023a28e to before 878757163eea684750107a31ea134c103863515dAffected
4f1fffa2376922f3d1d506e49c0fd445b023a28e to before 3407240cde132a4b72d6429a2625a09a2f78adafAffected
4f1fffa2376922f3d1d506e49c0fd445b023a28e to before 013a9a3da46c5dabcf18f65ea6a47874ba12a15dAffected
4f1fffa2376922f3d1d506e49c0fd445b023a28e to before 4be31c943a3a27a5a0251dbb8f5cb89059ec3d5aAffected
6.6.32 to before 6.6.145Affected

LinuxLinux

6.8Affected
before 6.8Not affected
6.6.145 through 6.6.*Not affected
6.12.96 through 6.12.*Not affected
6.18.39 through 6.18.*Not affected
7.1.4 through 7.1.*Not affected
7.2 and laterNot affected

References

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