MEDIUM · 5.5

CVE-2024-35795

In the Linux kernel, the following vulnerability has been resolved: drm/amdgpu: fix deadlock while reading mqd from debugfs An errant disk backup on my desktop got into debugfs and triggered the fol...

Vulnerability Description

In the Linux kernel, the following vulnerability has been resolved: drm/amdgpu: fix deadlock while reading mqd from debugfs An errant disk backup on my desktop got into debugfs and triggered the following deadlock scenario in the amdgpu debugfs files. The machine also hard-resets immediately after those lines are printed (although I wasn't able to reproduce that part when reading by hand): [ 1318.016074][ T1082] ====================================================== [ 1318.016607][ T1082] WARNING: possible circular locking dependency detected [ 1318.017107][ T1082] 6.8.0-rc7-00015-ge0c8221b72c0 #17 Not tainted [ 1318.017598][ T1082] ------------------------------------------------------ [ 1318.018096][ T1082] tar/1082 is trying to acquire lock: [ 1318.018585][ T1082] ffff98c44175d6a0 (&mm->mmap_lock){++++}-{3:3}, at: __might_fault+0x40/0x80 [ 1318.019084][ T1082] [ 1318.019084][ T1082] but task is already holding lock: [ 1318.020052][ T1082] ffff98c4c13f55f8 (reservation_ww_class_mutex){+.+.}-{3:3}, at: amdgpu_debugfs_mqd_read+0x6a/0x250 [amdgpu] [ 1318.020607][ T1082] [ 1318.020607][ T1082] which lock already depends on the new lock. [ 1318.020607][ T1082] [ 1318.022081][ T1082] [ 1318.022081][ T1082] the existing dependency chain (in reverse order) is: [ 1318.023083][ T1082] [ 1318.023083][ T1082] -> #2 (reservation_ww_class_mutex){+.+.}-{3:3}: [ 1318.024114][ T1082] __ww_mutex_lock.constprop.0+0xe0/0x12f0 [ 1318.024639][ T1082] ww_mutex_lock+0x32/0x90 [ 1318.025161][ T1082] dma_resv_lockdep+0x18a/0x330 [ 1318.025683][ T1082] do_one_initcall+0x6a/0x350 [ 1318.026210][ T1082] kernel_init_freeable+0x1a3/0x310 [ 1318.026728][ T1082] kernel_init+0x15/0x1a0 [ 1318.027242][ T1082] ret_from_fork+0x2c/0x40 [ 1318.027759][ T1082] ret_from_fork_asm+0x11/0x20 [ 1318.028281][ T1082] [ 1318.028281][ T1082] -> #1 (reservation_ww_class_acquire){+.+.}-{0:0}: [ 1318.029297][ T1082] dma_resv_lockdep+0x16c/0x330 [ 1318.029790][ T1082] do_one_initcall+0x6a/0x350 [ 1318.030263][ T1082] kernel_init_freeable+0x1a3/0x310 [ 1318.030722][ T1082] kernel_init+0x15/0x1a0 [ 1318.031168][ T1082] ret_from_fork+0x2c/0x40 [ 1318.031598][ T1082] ret_from_fork_asm+0x11/0x20 [ 1318.032011][ T1082] [ 1318.032011][ T1082] -> #0 (&mm->mmap_lock){++++}-{3:3}: [ 1318.032778][ T1082] __lock_acquire+0x14bf/0x2680 [ 1318.033141][ T1082] lock_acquire+0xcd/0x2c0 [ 1318.033487][ T1082] __might_fault+0x58/0x80 [ 1318.033814][ T1082] amdgpu_debugfs_mqd_read+0x103/0x250 [amdgpu] [ 1318.034181][ T1082] full_proxy_read+0x55/0x80 [ 1318.034487][ T1082] vfs_read+0xa7/0x360 [ 1318.034788][ T1082] ksys_read+0x70/0xf0 [ 1318.035085][ T1082] do_syscall_64+0x94/0x180 [ 1318.035375][ T1082] entry_SYSCALL_64_after_hwframe+0x46/0x4e [ 1318.035664][ T1082] [ 1318.035664][ T1082] other info that might help us debug this: [ 1318.035664][ T1082] [ 1318.036487][ T1082] Chain exists of: [ 1318.036487][ T1082] &mm->mmap_lock --> reservation_ww_class_acquire --> reservation_ww_class_mutex [ 1318.036487][ T1082] [ 1318.037310][ T1082] Possible unsafe locking scenario: [ 1318.037310][ T1082] [ 1318.037838][ T1082] CPU0 CPU1 [ 1318.038101][ T1082] ---- ---- [ 1318.038350][ T1082] lock(reservation_ww_class_mutex); [ 1318.038590][ T1082] lock(reservation_ww_class_acquire); [ 1318.038839][ T1082] lock(reservation_ww_class_mutex); [ 1318.039083][ T1082] rlock(&mm->mmap_lock); [ 1318.039328][ T1082] [ 1318.039328][ T1082] *** DEADLOCK *** [ 1318.039328][ T1082] [ 1318.040029][ T1082] 1 lock held by tar/1082: [ 1318.040259][ T1082] #0: ffff98c4c13f55f8 (reservation_ww_class_mutex){+.+.}-{3:3}, at: amdgpu_debugfs_mqd_read+0x6a/0x250 [amdgpu] [ 1318.040560][ T1082] [ 1318.040560][ T1082] stack backtrace: [ ---truncated---

CVSS Score

5.5

MEDIUM

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Attack Vector
LOCAL
Attack Complexity
LOW
Privileges Required
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH

Affected Products

VendorProductVersions
LinuxLinux Kernel>= 6.5, < 6.6.24

Related Weaknesses (CWE)

References

FAQ

What is CVE-2024-35795?

CVE-2024-35795 is a vulnerability with a CVSS score of 5.5 (MEDIUM). In the Linux kernel, the following vulnerability has been resolved: drm/amdgpu: fix deadlock while reading mqd from debugfs An errant disk backup on my desktop got into debugfs and triggered the fol...

How severe is CVE-2024-35795?

CVE-2024-35795 has been rated MEDIUM with a CVSS base score of 5.5/10. Review the CVSS metrics above for detailed severity breakdown.

Is there a patch for CVE-2024-35795?

Check the references section above for vendor advisories and patch information. Affected products include: Linux Linux Kernel.