cifs: Fix memory leak when build ntlmssp negotiate blob failed

Summary

In the Linux kernel, the following vulnerability has been resolved: cifs: Fix memory leak when build ntlmssp negotiate blob failed There is a memory leak when mount cifs: unreferenced object 0xffff888166059600 (size 448): comm "mount.cifs", pid 51391, jiffies 4295596373 (age 330.596s) hex dump (first 32 bytes): fe 53 4d 42 40 00 00 00 00 00 00 00 01 00 82 00 .SMB@........... 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ backtrace: [<0000000060609a61>] mempool_alloc+0xe1/0x260 [<00000000adfa6c63>] cifs_small_buf_get+0x24/0x60 [<00000000ebb404c7>] __smb2_plain_req_init+0x32/0x460 [<00000000bcf875b4>] SMB2_sess_alloc_buffer+0xa4/0x3f0 [<00000000753a2987>] SMB2_sess_auth_rawntlmssp_negotiate+0xf5/0x480 [<00000000f0c1f4f9>] SMB2_sess_setup+0x253/0x410 [<00000000a8b83303>] cifs_setup_session+0x18f/0x4c0 [<00000000854bd16d>] cifs_get_smb_ses+0xae7/0x13c0 [<000000006cbc43d9>] mount_get_conns+0x7a/0x730 [<000000005922d816>] cifs_mount+0x103/0xd10 [<00000000e33def3b>] cifs_smb3_do_mount+0x1dd/0xc90 [<0000000078034979>] smb3_get_tree+0x1d5/0x300 [<000000004371f980>] vfs_get_tree+0x41/0xf0 [<00000000b670d8a7>] path_mount+0x9b3/0xdd0 [<000000005e839a7d>] __x64_sys_mount+0x190/0x1d0 [<000000009404c3b9>] do_syscall_64+0x35/0x80 When build ntlmssp negotiate blob failed, the session setup request should be freed.

Timeline

1. Sep 17, 2025, 2:56 PM UTCCVE published
2. Jan 14, 2026, 6:36 PM UTCCISA SSVC assessment

   Exploitation: none · Automatable: no · Technical impact: partial

3. May 11, 2026, 7:18 PM UTCRecord last updated

Affected versions

• Linux Linux

  Version range not reported

• Linux Linux

  5.16

References 2