CVE-2022-50076: cifs: Fix memory leak on the deferred close

Severity: medium (CVSS 5.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2025-06-18 · updated 2026-06-17
Weakness: CWE-401

Description

In the Linux kernel, the following vulnerability has been resolved: cifs: Fix memory leak on the deferred close xfstests on smb21 report kmemleak as below: unreferenced object 0xffff8881767d6200 (size 64): comm "xfs_io", pid 1284, jiffies 4294777434 (age 20.789s) hex dump (first 32 bytes): 80 5a d0 11 81 88 ff ff 78 8a aa 63 81 88 ff ff .Z......x..c.... 00 71 99 76 81 88 ff ff 00 00 00 00 00 00 00 00 .q.v............ backtrace: [<00000000ad04e6ea>] cifs_close+0x92/0x2c0 [<0000000028b93c82>] __fput+0xff/0x3f0 [<00000000d8116851>] task_work_run+0x85/0xc0 [<0000000027e14f9e>] do_exit+0x5e5/0x1240 [<00000000fb492b95>] do_group_exit+0x58/0xe0 [<00000000129a32d9>] __x64_sys_exit_group+0x28/0x30 [<00000000e3f7d8e9>] do_syscall_64+0x35/0x80 [<00000000102e8a0b>] entry_SYSCALL_64_after_hwframe+0x46/0xb0 When cancel the deferred close work, we should also cleanup the struct cifs_deferred_close.

Affected products

Linux kernel: from 5.13.12 before 5.14; from 5.14.1 before 5.15.63; from 5.16 before 5.19.4; 5.14, 5.14-rc6, 5.14-rc7, 6.0-rc1 — fixed in 5.14, 5.15.63, 5.19.4

How to fix

Upgrade to a fixed version: Linux kernel 5.14, 5.15.63, 5.19.4. Check the vendor advisory for mitigations.

References

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