{"cve":"CVE-2024-35795","nvd":{"published":"2024-05-17T14:15:11.440","modified":"2026-06-17T07:35:23.717","status":"Analyzed","description":"In the Linux kernel, the following vulnerability has been resolved:\n\ndrm/amdgpu: fix deadlock while reading mqd from debugfs\n\nAn errant disk backup on my desktop got into debugfs and triggered the\nfollowing deadlock scenario in the amdgpu debugfs files. The machine\nalso hard-resets immediately after those lines are printed (although I\nwasn't able to reproduce that part when reading by hand):\n\n[ 1318.016074][ T1082] ======================================================\n[ 1318.016607][ T1082] WARNING: possible circular locking dependency detected\n[ 1318.017107][ T1082] 6.8.0-rc7-00015-ge0c8221b72c0 #17 Not tainted\n[ 1318.017598][ T1082] ------------------------------------------------------\n[ 1318.018096][ T1082] tar/1082 is trying to acquire lock:\n[ 1318.018585][ T1082] ffff98c44175d6a0 (&mm->mmap_lock){++++}-{3:3}, at: __might_fault+0x40/0x80\n[ 1318.019084][ T1082]\n[ 1318.019084][ T1082] but task is already holding lock:\n[ 1318.020052][ T1082] ffff98c4c13f55f8 (reservation_ww_class_mutex){+.+.}-{3:3}, at: amdgpu_debugfs_mqd_read+0x6a/0x250 [amdgpu]\n[ 1318.020607][ T1082]\n[ 1318.020607][ T1082] which lock already depends on the new lock.\n[ 1318.020607][ T1082]\n[ 1318.022081][ T1082]\n[ 1318.022081][ T1082] the existing dependency chain (in reverse order) is:\n[ 1318.023083][ T1082]\n[ 1318.023083][ T1082] -> #2 (reservation_ww_class_mutex){+.+.}-{3:3}:\n[ 1318.024114][ T1082]        __ww_mutex_lock.constprop.0+0xe0/0x12f0\n[ 1318.024639][ T1082]        ww_mutex_lock+0x32/0x90\n[ 1318.025161][ T1082]        dma_resv_lockdep+0x18a/0x330\n[ 1318.025683][ T1082]        do_one_initcall+0x6a/0x350\n[ 1318.026210][ T1082]        kernel_init_freeable+0x1a3/0x310\n[ 1318.026728][ T1082]        kernel_init+0x15/0x1a0\n[ 1318.027242][ T1082]        ret_from_fork+0x2c/0x40\n[ 1318.027759][ T1082]        ret_from_fork_asm+0x11/0x20\n[ 1318.028281][ T1082]\n[ 1318.028281][ T1082] -> #1 (reservation_ww_class_acquire){+.+.}-{0:0}:\n[ 1318.029297][ T1082]        dma_resv_lockdep+0x16c/0x330\n[ 1318.029790][ T1082]        do_one_initcall+0x6a/0x350\n[ 1318.030263][ T1082]        kernel_init_freeable+0x1a3/0x310\n[ 1318.030722][ T1082]        kernel_init+0x15/0x1a0\n[ 1318.031168][ T1082]        ret_from_fork+0x2c/0x40\n[ 1318.031598][ T1082]        ret_from_fork_asm+0x11/0x20\n[ 1318.032011][ T1082]\n[ 1318.032011][ T1082] -> #0 (&mm->mmap_lock){++++}-{3:3}:\n[ 1318.032778][ T1082]        __lock_acquire+0x14bf/0x2680\n[ 1318.033141][ T1082]        lock_acquire+0xcd/0x2c0\n[ 1318.033487][ T1082]        __might_fault+0x58/0x80\n[ 1318.033814][ T1082]        amdgpu_debugfs_mqd_read+0x103/0x250 [amdgpu]\n[ 1318.034181][ T1082]        full_proxy_read+0x55/0x80\n[ 1318.034487][ T1082]        vfs_read+0xa7/0x360\n[ 1318.034788][ T1082]        ksys_read+0x70/0xf0\n[ 1318.035085][ T1082]        do_syscall_64+0x94/0x180\n[ 1318.035375][ T1082]        entry_SYSCALL_64_after_hwframe+0x46/0x4e\n[ 1318.035664][ T1082]\n[ 1318.035664][ T1082] other info that might help us debug this:\n[ 1318.035664][ T1082]\n[ 1318.036487][ T1082] Chain exists of:\n[ 1318.036487][ T1082]   &mm->mmap_lock --> reservation_ww_class_acquire --> reservation_ww_class_mutex\n[ 1318.036487][ T1082]\n[ 1318.037310][ T1082]  Possible unsafe locking scenario:\n[ 1318.037310][ T1082]\n[ 1318.037838][ T1082]        CPU0                    CPU1\n[ 1318.038101][ T1082]        ----                    ----\n[ 1318.038350][ T1082]   lock(reservation_ww_class_mutex);\n[ 1318.038590][ T1082]                                lock(reservation_ww_class_acquire);\n[ 1318.038839][ T1082]                                lock(reservation_ww_class_mutex);\n[ 1318.039083][ T1082]   rlock(&mm->mmap_lock);\n[ 1318.039328][ T1082]\n[ 1318.039328][ T1082]  *** DEADLOCK ***\n[ 1318.039328][ T1082]\n[ 1318.040029][ T1082] 1 lock held by tar/1082:\n[ 1318.040259][ T1082]  #0: ffff98c4c13f55f8 (reservation_ww_class_mutex){+.+.}-{3:3}, at: amdgpu_debugfs_mqd_read+0x6a/0x250 [amdgpu]\n[ 1318.040560][ T1082]\n[ 1318.040560][ T1082] stack backtrace:\n[\n---truncated---","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","score":5.5},"cwes":["CWE-667"],"references":["https://git.kernel.org/stable/c/197f6d6987c55860f6eea1c93e4f800c59078874","https://git.kernel.org/stable/c/4687e3c6ee877ee25e57b984eca00be53b9a8db5","https://git.kernel.org/stable/c/8678b1060ae2b75feb60b87e5b75e17374e3c1c5","https://git.kernel.org/stable/c/8b03556da6e576c62664b6cd01809e4a09d53b5b","https://git.kernel.org/stable/c/197f6d6987c55860f6eea1c93e4f800c59078874"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T21:50:30.954589733+00:00"},"epss":{"cve":"CVE-2024-35795","score":0.00174,"percentile":0.06802,"date":"2026-10-31"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}