CVE-2024-26757

CVE Details

Release Date:

2024-04-03

Description

In the Linux kernel, the following vulnerability has been resolved:\nmd: Don't ignore read-only array in md_check_recovery()\nUsually if the array is not read-write, md_check_recovery() won't\nregister new sync_thread in the first place. And if the array is\nread-write and sync_thread is registered, md_set_readonly() will\nunregister sync_thread before setting the array read-only. md/raid\nfollow this behavior hence there is no problem.\nAfter commit f52f5c71f3d4 ('md: fix stopping sync thread'), following\nhang can be triggered by test shell/integrity-caching.sh:\n1) array is read-only. dm-raid update super block:\nrs_update_sbs\nro = mddev->ro\nmddev->ro = 0\n-> set array read-write\nmd_update_sb\n2) register new sync thread concurrently.\n3) dm-raid set array back to read-only:\nrs_update_sbs\nmddev->ro = ro\n4) stop the array:\nraid_dtr\nmd_stop\nstop_sync_thread\nset_bit(MD_RECOVERY_INTR, &mddev->recovery);\nmd_wakeup_thread_directly(mddev->sync_thread);\nwait_event(..., !test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))\n5) sync thread done:\nmd_do_sync\nset_bit(MD_RECOVERY_DONE, &mddev->recovery);\nmd_wakeup_thread(mddev->thread);\n6) daemon thread can't unregister sync thread:\nmd_check_recovery\nif (!md_is_rdwr(mddev) &&\n!test_bit(MD_RECOVERY_NEEDED, &mddev->recovery))\nreturn;\n-> -> MD_RECOVERY_RUNNING can't be cleared, hence step 4 hang;\nThe root cause is that dm-raid manipulate 'mddev->ro' by itself,\nhowever, dm-raid really should stop sync thread before setting the\narray read-only. Unfortunately, I need to read more code before I\ncan refacter the handler of 'mddev->ro' in dm-raid, hence let's fix\nthe problem the easy way for now to prevent dm-raid regression.

See more information about CVE-2024-26757 from MITRE CVE dictionary and NIST NVD

CVSS Scoring

NOTE: The following CVSS v3.1 metrics and score provided are preliminary and subject to review.

Base Score:	4.4	CVSS Vector:	CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H
Attack Vector:	Local network	Attack Complexity:	Low
Privileges Required:	High	User Interaction:	None
Scope:	Unchanged	Confidentiality Impact:	None
Integrity Impact:	None	Availability Impact:	High

Errata information

Platform	Errata	Release Date
Oracle Linux version 9 (kernel)	ELSA-2024-9315	2024-11-14