CVE-2024-50031

Published Oct 21, 2024

Last updated 7 months ago

Overview

Description
In the Linux kernel, the following vulnerability has been resolved: drm/v3d: Stop the active perfmon before being destroyed When running `kmscube` with one or more performance monitors enabled via `GALLIUM_HUD`, the following kernel panic can occur: [ 55.008324] Unable to handle kernel paging request at virtual address 00000000052004a4 [ 55.008368] Mem abort info: [ 55.008377] ESR = 0x0000000096000005 [ 55.008387] EC = 0x25: DABT (current EL), IL = 32 bits [ 55.008402] SET = 0, FnV = 0 [ 55.008412] EA = 0, S1PTW = 0 [ 55.008421] FSC = 0x05: level 1 translation fault [ 55.008434] Data abort info: [ 55.008442] ISV = 0, ISS = 0x00000005, ISS2 = 0x00000000 [ 55.008455] CM = 0, WnR = 0, TnD = 0, TagAccess = 0 [ 55.008467] GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0 [ 55.008481] user pgtable: 4k pages, 39-bit VAs, pgdp=00000001046c6000 [ 55.008497] [00000000052004a4] pgd=0000000000000000, p4d=0000000000000000, pud=0000000000000000 [ 55.008525] Internal error: Oops: 0000000096000005 [#1] PREEMPT SMP [ 55.008542] Modules linked in: rfcomm [...] vc4 v3d snd_soc_hdmi_codec drm_display_helper gpu_sched drm_shmem_helper cec drm_dma_helper drm_kms_helper i2c_brcmstb drm drm_panel_orientation_quirks snd_soc_core snd_compress snd_pcm_dmaengine snd_pcm snd_timer snd backlight [ 55.008799] CPU: 2 PID: 166 Comm: v3d_bin Tainted: G C 6.6.47+rpt-rpi-v8 #1 Debian 1:6.6.47-1+rpt1 [ 55.008824] Hardware name: Raspberry Pi 4 Model B Rev 1.5 (DT) [ 55.008838] pstate: 20000005 (nzCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--) [ 55.008855] pc : __mutex_lock.constprop.0+0x90/0x608 [ 55.008879] lr : __mutex_lock.constprop.0+0x58/0x608 [ 55.008895] sp : ffffffc080673cf0 [ 55.008904] x29: ffffffc080673cf0 x28: 0000000000000000 x27: ffffff8106188a28 [ 55.008926] x26: ffffff8101e78040 x25: ffffff8101baa6c0 x24: ffffffd9d989f148 [ 55.008947] x23: ffffffda1c2a4008 x22: 0000000000000002 x21: ffffffc080673d38 [ 55.008968] x20: ffffff8101238000 x19: ffffff8104f83188 x18: 0000000000000000 [ 55.008988] x17: 0000000000000000 x16: ffffffda1bd04d18 x15: 00000055bb08bc90 [ 55.009715] x14: 0000000000000000 x13: 0000000000000000 x12: ffffffda1bd4cbb0 [ 55.010433] x11: 00000000fa83b2da x10: 0000000000001a40 x9 : ffffffda1bd04d04 [ 55.011162] x8 : ffffff8102097b80 x7 : 0000000000000000 x6 : 00000000030a5857 [ 55.011880] x5 : 00ffffffffffffff x4 : 0300000005200470 x3 : 0300000005200470 [ 55.012598] x2 : ffffff8101238000 x1 : 0000000000000021 x0 : 0300000005200470 [ 55.013292] Call trace: [ 55.013959] __mutex_lock.constprop.0+0x90/0x608 [ 55.014646] __mutex_lock_slowpath+0x1c/0x30 [ 55.015317] mutex_lock+0x50/0x68 [ 55.015961] v3d_perfmon_stop+0x40/0xe0 [v3d] [ 55.016627] v3d_bin_job_run+0x10c/0x2d8 [v3d] [ 55.017282] drm_sched_main+0x178/0x3f8 [gpu_sched] [ 55.017921] kthread+0x11c/0x128 [ 55.018554] ret_from_fork+0x10/0x20 [ 55.019168] Code: f9400260 f1001c1f 54001ea9 927df000 (b9403401) [ 55.019776] ---[ end trace 0000000000000000 ]--- [ 55.020411] note: v3d_bin[166] exited with preempt_count 1 This issue arises because, upon closing the file descriptor (which happens when we interrupt `kmscube`), the active performance monitor is not stopped. Although all perfmons are destroyed in `v3d_perfmon_close_file()`, the active performance monitor's pointer (`v3d->active_perfmon`) is still retained. If `kmscube` is run again, the driver will attempt to stop the active performance monitor using the stale pointer in `v3d->active_perfmon`. However, this pointer is no longer valid because the previous process has already terminated, and all performance monitors associated with it have been destroyed and freed. To fix this, when the active performance monitor belongs to a given process, explicitly stop it before destroying and freeing it.
Source
416baaa9-dc9f-4396-8d5f-8c081fb06d67
NVD status
Modified
Products
linux_kernel

Risk scores

CVSS 3.1

Type
Primary
Base score
5.5
Impact score
3.6
Exploitability score
1.8
Vector string
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Severity
MEDIUM

Weaknesses

nvd@nist.gov
NVD-CWE-noinfo

Social media

Hype score
Not currently trending

Configurations

  1. In the Linux kernel, the following vulnerability has been resolved: coresight: tmc-etr: Fix race condition between sysfs and perf mode When trying to run perf and sysfs mode simultaneously, the WARN_ON() in tmc_etr_enable_hw() is triggered sometimes: WARNING: CPU: 42 PID: 3911571 at drivers/hwtracing/coresight/coresight-tmc-etr.c:1060 tmc_etr_enable_hw+0xc0/0xd8 [coresight_tmc] [..snip..] Call trace: tmc_etr_enable_hw+0xc0/0xd8 [coresight_tmc] (P) tmc_enable_etr_sink+0x11c/0x250 [coresight_tmc] (L) tmc_enable_etr_sink+0x11c/0x250 [coresight_tmc] coresight_enable_path+0x1c8/0x218 [coresight] coresight_enable_sysfs+0xa4/0x228 [coresight] enable_source_store+0x58/0xa8 [coresight] dev_attr_store+0x20/0x40 sysfs_kf_write+0x4c/0x68 kernfs_fop_write_iter+0x120/0x1b8 vfs_write+0x2c8/0x388 ksys_write+0x74/0x108 __arm64_sys_write+0x24/0x38 el0_svc_common.constprop.0+0x64/0x148 do_el0_svc+0x24/0x38 el0_svc+0x3c/0x130 el0t_64_sync_handler+0xc8/0xd0 el0t_64_sync+0x1ac/0x1b0 ---[ end trace 0000000000000000 ]--- Since the enablement of sysfs mode is separeted into two critical regions, one for sysfs buffer allocation and another for hardware enablement, it's possible to race with the perf mode. Fix this by double check whether the perf mode's been used before enabling the hardware in sysfs mode. mode: [sysfs mode] [perf mode] tmc_etr_get_sysfs_buffer() spin_lock(&drvdata->spinlock) [sysfs buffer allocation] spin_unlock(&drvdata->spinlock) spin_lock(&drvdata->spinlock) tmc_etr_enable_hw() drvdata->etr_buf = etr_perf->etr_buf spin_unlock(&drvdata->spinlock) spin_lock(&drvdata->spinlock) tmc_etr_enable_hw() WARN_ON(drvdata->etr_buf) // WARN sicne etr_buf initialized at the perf side spin_unlock(&drvdata->spinlock) With this fix, we retain the check for CS_MODE_PERF in get_etr_sysfs_buf. This ensures we verify whether the perf mode's already running before we actually allocate the buffer. Then we can save the time of allocating/freeing the sysfs buffer if race with the perf mode.CVE-2026-46272