CVE Published: 03/04/2024 |
CVE Updated: 05/11/2024 |
CVE Year: 2024 Source: Linux |
Vendor: Linux |
Product: Linux Status : PUBLISHED
CVE-2024-26758 Description
In the Linux kernel, the following vulnerability has been resolved:
md: Don\'t ignore suspended array in md_check_recovery()
mddev_suspend() never stop sync_thread, hence it doesn\'t make sense to
ignore suspended array in md_check_recovery(), which might cause
sync_thread can\'t be unregistered.
After commit f52f5c71f3d4 ("md: fix stopping sync thread"), following
hang can be triggered by test shell/integrity-caching.sh:
1) suspend the array:
raid_postsuspend
mddev_suspend
2) stop the array:
raid_dtr
md_stop
__md_stop_writes
stop_sync_thread
set_bit(MD_RECOVERY_INTR, &mddev->recovery);
md_wakeup_thread_directly(mddev->sync_thread);
wait_event(..., !test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
3) sync thread done:
md_do_sync
set_bit(MD_RECOVERY_DONE, &mddev->recovery);
md_wakeup_thread(mddev->thread);
4) daemon thread can\'t unregister sync thread:
md_check_recovery
if (mddev->suspended)
return; -> return directly
md_read_sync_thread
clear_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
-> MD_RECOVERY_RUNNING can\'t be cleared, hence step 2 hang;
This problem is not just related to dm-raid, fix it by ignoring
suspended array in md_check_recovery(). And follow up patches will
improve dm-raid better to frozen sync thread during suspend.