In the Linux kernel, the following vulnerability has been resolved: md: fix resync softlockup when bitmap size is less than array size Is is reported that for dm-raid10, lvextend + lvchange --syncaction will trigger following softlockup: kernel:watchdog: BUG: soft lockup - CPU#3 stuck for 26s! [mdX_resync:6976] CPU: 7 PID: 3588 Comm: mdX_resync Kdump: loaded Not tainted 6.9.0-rc4-next-20240419 #1 RIP: 0010:_raw_spin_unlock_irq+0x13/0x30 Call Trace: <TASK> md_bitmap_start_sync+0x6b/0xf0 raid10_sync_request+0x25c/0x1b40 [raid10] md_do_sync+0x64b/0x1020 md_thread+0xa7/0x170 kthread+0xcf/0x100 ret_from_fork+0x30/0x50 ret_from_fork_asm+0x1a/0x30 And the detailed process is as follows: md_do_sync j = mddev->resync_min while (j < max_sectors) sectors = raid10_sync_request(mddev, j, &skipped) if (!md_bitmap_start_sync(…, &sync_blocks)) // md_bitmap_start_sync set sync_blocks to 0 return sync_blocks + sectors_skippe; // sectors = 0; j += sectors; // j never change Root cause is that commit 301867b1c168 (“md/raid10: check slab-out-of-bounds in md_bitmap_get_counter”) return early from md_bitmap_get_counter(), without setting returned blocks. Fix this problem by always set returned blocks from md_bitmap_get_counter"(), as it used to be. Noted that this patch just fix the softlockup problem in kernel, the case that bitmap size doesn’t match array size still need to be fixed.
OS | Version | Architecture | Package | Version | Filename |
---|---|---|---|---|---|
Debian | 12 | all | linux | <= 6.1.76-1 | linux_6.1.76-1_all.deb |
Debian | 11 | all | linux | <= 5.10.209-2 | linux_5.10.209-2_all.deb |
Debian | 10 | all | linux | < 4.19.316-1 | linux_4.19.316-1_all.deb |
Debian | 999 | all | linux | < 6.8.12-1 | linux_6.8.12-1_all.deb |
Debian | 13 | all | linux | < 6.8.12-1 | linux_6.8.12-1_all.deb |