CVE-2024-36966

erofs: reliably distinguish block based and fscache mode

MEDIUM
5.5
CVSS Score
Published: June 8, 2024 at 12:52 PM UTC
Updated: June 17, 2026 at 07:37 AM UTC
1 product affected across 1 vendorLinux Kernel

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Severity
MEDIUM5.5
Exploit prediction
EPSS 0.2%
SSVC
No known exploit

Description

In the Linux kernel, the following vulnerability has been resolved: erofs: reliably distinguish block based and fscache mode When erofs_kill_sb() is called in block dev based mode, s_bdev may not have been initialised yet, and if CONFIG_EROFS_FS_ONDEMAND is enabled, it will be mistaken for fscache mode, and then attempt to free an anon_dev that has never been allocated, triggering the following warning: ============================================ ida_free called for id=0 which is not allocated. WARNING: CPU: 14 PID: 926 at lib/idr.c:525 ida_free+0x134/0x140 Modules linked in: CPU: 14 PID: 926 Comm: mount Not tainted 6.9.0-rc3-dirty #630 RIP: 0010:ida_free+0x134/0x140 Call Trace: <TASK> erofs_kill_sb+0x81/0x90 deactivate_locked_super+0x35/0x80 get_tree_bdev+0x136/0x1e0 vfs_get_tree+0x2c/0xf0 do_new_mount+0x190/0x2f0 [...] ============================================ Now when erofs_kill_sb() is called, erofs_sb_info must have been initialised, so use sbi->fsid to distinguish between the two modes.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

6.6 ≤ v < 6.6.326.6 ≤ v < 6.8.116.6 ≤ v < 6.96.7 ≤ v < 6.8.116.66.9 rc16.9 rc26.9 rc36.9 rc46.9 rc56.9 rc6aca740cecbe57b12bd9c1fc632092af5ebacda0c
Vendor states this is fixed in 7af2ae1b1531feab5d38ec9c8f472dc6cceb4606 (fixed)
Vendor states this is fixed in dcdd49701e429c55b3644fd70fc58d85745f8cfe (fixed)
Vendor states this is fixed in f9b877a7ee312ec8ce17598a7ef85cb820d7c371 (fixed)
Vendor states this is fixed in 6.6 (unaffected)
Vendor states this is fixed in 6.6.32 (unaffected)
Vendor states this is fixed in 6.8.11 (unaffected)
Vendor states this is fixed in 6.9 (unaffected)

References (3)

Patch
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/7af2ae1b1531feab5d38ec9c8f472dc6cceb4606
Patch
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/dcdd49701e429c55b3644fd70fc58d85745f8cfe
Patch
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/f9b877a7ee312ec8ce17598a7ef85cb820d7c371

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

Attack Vector
LOCAL
Complexity
LOW
Privileges
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusANALYZED
CWE
CWE-824

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