CVE-2026-45961: gfs2: fix memory leaks in gfs2_fill_super error path

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: 2026-05-27 · updated 2026-10-30
Weakness: CWE-401

Description

In the Linux kernel, the following vulnerability has been resolved: gfs2: fix memory leaks in gfs2_fill_super error path Fix two memory leaks in the gfs2_fill_super() error handling path when transitioning a filesystem to read-write mode fails. First leak: kthread objects (thread_struct, task_struct, etc.) When gfs2_freeze_lock_shared() fails after init_threads() succeeds, the created kernel threads (logd and quotad) are never destroyed. This occurs because the fail_per_node label doesn't call gfs2_destroy_threads(). Second leak: quota bitmap buffer (8192 bytes) When gfs2_make_fs_rw() fails after gfs2_quota_init() succeeds but before other operations complete, the allocated quota bitmap is never freed. The fix moves thread cleanup to the fail_per_node label to handle all error paths uniformly. gfs2_destroy_threads() is safe to call unconditionally as it checks for NULL pointers. Quota cleanup is added in gfs2_make_fs_rw() to properly handle the withdrawal case where quota initialization succeeds but the filesystem is then withdrawn. Thread leak backtrace (gfs2_freeze_lock_shared failure): unreferenced object 0xffff88801d7bca80 (size 4480): copy_process+0x3a1/0x4670 kernel/fork.c:2422 kernel_clone+0xf3/0x6e0 kernel/fork.c:2779 kthread_create_on_node+0x100/0x150 kernel/kthread.c:478 init_threads+0xab/0x350 fs/gfs2/ops_fstype.c:611 gfs2_fill_super+0xe5c/0x1240 fs/gfs2/ops_fstype.c:1265 Quota leak backtrace (gfs2_make_fs_rw failure): unreferenced object 0xffff88812de7c000 (size 8192): gfs2_quota_init+0xe5/0x820 fs/gfs2/quota.c:1409 gfs2_make_fs_rw+0x7a/0xe0 fs/gfs2/super.c:149 gfs2_fill_super+0xfbb/0x1240 fs/gfs2/ops_fstype.c:1275

Affected products

Linux kernel: from 5.10.173 before 5.11; from 5.15.99 before 5.16; from 6.1.16 before 6.2; from 6.2.3 before 6.19.4 — fixed in 5.11, 5.16, 6.2, 6.19.4
Linux: from 6.1.16 before 6.1.191; from 5.10.173 before 5.11; from 5.15.99 before 5.16; from 6.2.3 before 6.3 — fixed in 6.1.191, 5.11, 5.16, 6.3

How to fix

Upgrade to a fixed version: Linux kernel 5.11, 5.16, 6.2, 6.19.4; Linux 6.1.191, 5.11, 5.16, 6.3. Check the vendor advisory for mitigations.

References

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