ghsa-3m73-m9xc-48pv
Vulnerability from github
In the Linux kernel, the following vulnerability has been resolved:
dm-raid456, md/raid456: fix a deadlock for dm-raid456 while io concurrent with reshape
For raid456, if reshape is still in progress, then IO across reshape position will wait for reshape to make progress. However, for dm-raid, in following cases reshape will never make progress hence IO will hang:
1) the array is read-only; 2) MD_RECOVERY_WAIT is set; 3) MD_RECOVERY_FROZEN is set;
After commit c467e97f079f ("md/raid6: use valid sector values to determine if an I/O should wait on the reshape") fix the problem that IO across reshape position doesn't wait for reshape, the dm-raid test shell/lvconvert-raid-reshape.sh start to hang:
[root@fedora ~]# cat /proc/979/stack [<0>] wait_woken+0x7d/0x90 [<0>] raid5_make_request+0x929/0x1d70 [raid456] [<0>] md_handle_request+0xc2/0x3b0 [md_mod] [<0>] raid_map+0x2c/0x50 [dm_raid] [<0>] __map_bio+0x251/0x380 [dm_mod] [<0>] dm_submit_bio+0x1f0/0x760 [dm_mod] [<0>] __submit_bio+0xc2/0x1c0 [<0>] submit_bio_noacct_nocheck+0x17f/0x450 [<0>] submit_bio_noacct+0x2bc/0x780 [<0>] submit_bio+0x70/0xc0 [<0>] mpage_readahead+0x169/0x1f0 [<0>] blkdev_readahead+0x18/0x30 [<0>] read_pages+0x7c/0x3b0 [<0>] page_cache_ra_unbounded+0x1ab/0x280 [<0>] force_page_cache_ra+0x9e/0x130 [<0>] page_cache_sync_ra+0x3b/0x110 [<0>] filemap_get_pages+0x143/0xa30 [<0>] filemap_read+0xdc/0x4b0 [<0>] blkdev_read_iter+0x75/0x200 [<0>] vfs_read+0x272/0x460 [<0>] ksys_read+0x7a/0x170 [<0>] __x64_sys_read+0x1c/0x30 [<0>] do_syscall_64+0xc6/0x230 [<0>] entry_SYSCALL_64_after_hwframe+0x6c/0x74
This is because reshape can't make progress.
For md/raid, the problem doesn't exist because register new sync_thread doesn't rely on the IO to be done any more:
1) If array is read-only, it can switch to read-write by ioctl/sysfs; 2) md/raid never set MD_RECOVERY_WAIT; 3) If MD_RECOVERY_FROZEN is set, mddev_suspend() doesn't hold 'reconfig_mutex', hence it can be cleared and reshape can continue by sysfs api 'sync_action'.
However, I'm not sure yet how to avoid the problem in dm-raid yet. This patch on the one hand make sure raid_message() can't change sync_thread() through raid_message() after presuspend(), on the other hand detect the above 3 cases before wait for IO do be done in dm_suspend(), and let dm-raid requeue those IO.
{
"affected": [],
"aliases": [
"CVE-2024-26962"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2024-05-01T06:15:12Z",
"severity": null
},
"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\u0027t 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\u0027t make progress.\n\nFor md/raid, the problem doesn\u0027t exist because register new sync_thread\ndoesn\u0027t 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\u0027t hold\n \u0027reconfig_mutex\u0027, hence it can be cleared and reshape can continue by\n sysfs api \u0027sync_action\u0027.\n\nHowever, I\u0027m not sure yet how to avoid the problem in dm-raid yet. This\npatch on the one hand make sure raid_message() can\u0027t 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.",
"id": "GHSA-3m73-m9xc-48pv",
"modified": "2024-05-01T06:31:42Z",
"published": "2024-05-01T06:31:42Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2024-26962"
},
{
"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"
}
],
"schema_version": "1.4.0",
"severity": []
}