{"id":"CVE-2024-26962","summary":"dm-raid456, md/raid456: fix a deadlock for dm-raid456 while io concurrent with reshape","details":"In the Linux kernel, the following vulnerability has been resolved:\n\ndm-raid456, md/raid456: fix a deadlock for dm-raid456 while io concurrent with reshape\n\nFor raid456, if reshape is still in progress, then IO across reshape\nposition will wait for reshape to make progress. However, for dm-raid,\nin following cases reshape will never make progress hence IO will hang:\n\n1) the array is read-only;\n2) MD_RECOVERY_WAIT is set;\n3) MD_RECOVERY_FROZEN is set;\n\nAfter commit c467e97f079f (\"md/raid6: use valid sector values to determine\nif an I/O should wait on the reshape\") fix the problem that IO across\nreshape position doesn't wait for reshape, the dm-raid test\nshell/lvconvert-raid-reshape.sh start to hang:\n\n[root@fedora ~]# cat /proc/979/stack\n[\u003c0\u003e] wait_woken+0x7d/0x90\n[\u003c0\u003e] raid5_make_request+0x929/0x1d70 [raid456]\n[\u003c0\u003e] md_handle_request+0xc2/0x3b0 [md_mod]\n[\u003c0\u003e] raid_map+0x2c/0x50 [dm_raid]\n[\u003c0\u003e] __map_bio+0x251/0x380 [dm_mod]\n[\u003c0\u003e] dm_submit_bio+0x1f0/0x760 [dm_mod]\n[\u003c0\u003e] __submit_bio+0xc2/0x1c0\n[\u003c0\u003e] submit_bio_noacct_nocheck+0x17f/0x450\n[\u003c0\u003e] submit_bio_noacct+0x2bc/0x780\n[\u003c0\u003e] submit_bio+0x70/0xc0\n[\u003c0\u003e] mpage_readahead+0x169/0x1f0\n[\u003c0\u003e] blkdev_readahead+0x18/0x30\n[\u003c0\u003e] read_pages+0x7c/0x3b0\n[\u003c0\u003e] page_cache_ra_unbounded+0x1ab/0x280\n[\u003c0\u003e] force_page_cache_ra+0x9e/0x130\n[\u003c0\u003e] page_cache_sync_ra+0x3b/0x110\n[\u003c0\u003e] filemap_get_pages+0x143/0xa30\n[\u003c0\u003e] filemap_read+0xdc/0x4b0\n[\u003c0\u003e] blkdev_read_iter+0x75/0x200\n[\u003c0\u003e] vfs_read+0x272/0x460\n[\u003c0\u003e] ksys_read+0x7a/0x170\n[\u003c0\u003e] __x64_sys_read+0x1c/0x30\n[\u003c0\u003e] do_syscall_64+0xc6/0x230\n[\u003c0\u003e] entry_SYSCALL_64_after_hwframe+0x6c/0x74\n\nThis is because reshape can't make progress.\n\nFor md/raid, the problem doesn't exist because register new sync_thread\ndoesn't rely on the IO to be done any more:\n\n1) If array is read-only, it can switch to read-write by ioctl/sysfs;\n2) md/raid never set MD_RECOVERY_WAIT;\n3) If MD_RECOVERY_FROZEN is set, mddev_suspend() doesn't hold\n   'reconfig_mutex', hence it can be cleared and reshape can continue by\n   sysfs api 'sync_action'.\n\nHowever, I'm not sure yet how to avoid the problem in dm-raid yet. This\npatch on the one hand make sure raid_message() can't change\nsync_thread() through raid_message() after presuspend(), on the other\nhand detect the above 3 cases before wait for IO do be done in\ndm_suspend(), and let dm-raid requeue those IO.","modified":"2026-04-02T10:06:33.821288Z","published":"2024-05-01T05:19:20.579Z","related":["SUSE-SU-2024:2135-1","SUSE-SU-2024:2203-1","SUSE-SU-2024:2973-1","SUSE-SU-2025:20008-1","SUSE-SU-2025:20028-1","SUSE-SU-2025:20166-1","SUSE-SU-2025:20249-1"],"database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2024/26xxx/CVE-2024-26962.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/41425f96d7aa59bc865f60f5dda3d7697b555677"},{"type":"WEB","url":"https://git.kernel.org/stable/c/5943a34bf6bab5801e08a55f63e1b8d5bc90dae1"},{"type":"WEB","url":"https://git.kernel.org/stable/c/a8d249d770cb357d16a2097b548d2e4c1c137304"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2024/26xxx/CVE-2024-26962.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2024-26962"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"c467e97f079f0019870c314996fae952cc768e82"},{"fixed":"5943a34bf6bab5801e08a55f63e1b8d5bc90dae1"},{"fixed":"a8d249d770cb357d16a2097b548d2e4c1c137304"},{"fixed":"41425f96d7aa59bc865f60f5dda3d7697b555677"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"0"},{"last_affected":"515d971cd26a40f710490d1566783f9c62b46d61"},{"last_affected":"4ce431c297558e30baa9226243a15d818320742b"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2024-26962.json"}}],"schema_version":"1.7.5"}