CVE-2026-45961 PUBLISHED

gfs2: fix memory leaks in gfs2_fill_super error path

Assigner: Linux
Reserved: 13.05.2026 Published: 27.05.2026 Updated: 27.05.2026

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gfs2_make_fs_rw() to properly handle the withdrawal case where quota initialization succeeds but the filesystem is then withdrawn.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

Product Status

Vendor Linux
Product Linux
Versions Default: unaffected
  • affected from b66f723bb552ad59c2acb5d45ea45c890f84498b to e54229ecf49add8451d5f765a32c86ab4446e06c (excl.)
  • affected from b66f723bb552ad59c2acb5d45ea45c890f84498b to da6f5bbc2e7902f578b503f2a4c3d8d09ca4b102 (excl.)
  • Version 2f8623377f3e0cfaa80558631b8694d02a492b4c is affected
  • Version c713ebf2fe3f469e4af4de60a3427689ffb7c5d7 is affected
  • Version c2191e507147b1a22e9170ebb2aaa0f2902fcbfa is affected
  • Version 9fc32dad3cdba18669c71893f3e6d96905b39b3f is affected
  • affected from 5.10.173 to 5.11 (excl.)
  • affected from 5.15.99 to 5.16 (excl.)
  • affected from 6.1.16 to 6.2 (excl.)
  • affected from 6.2.3 to 6.3 (excl.)
Vendor Linux
Product Linux
Versions Default: affected
  • Version 6.3 is affected
  • unaffected from 0 to 6.3 (excl.)
  • unaffected from 6.19.4 to 6.19.* (incl.)
  • unaffected from 7.0 to * (incl.)

References