CVE-2023-52817

Published May 21, 2024

Last updated 9 months ago

Overview

Description
In the Linux kernel, the following vulnerability has been resolved: drm/amdgpu: Fix a null pointer access when the smc_rreg pointer is NULL In certain types of chips, such as VEGA20, reading the amdgpu_regs_smc file could result in an abnormal null pointer access when the smc_rreg pointer is NULL. Below are the steps to reproduce this issue and the corresponding exception log: 1. Navigate to the directory: /sys/kernel/debug/dri/0 2. Execute command: cat amdgpu_regs_smc 3. Exception Log:: [4005007.702554] BUG: kernel NULL pointer dereference, address: 0000000000000000 [4005007.702562] #PF: supervisor instruction fetch in kernel mode [4005007.702567] #PF: error_code(0x0010) - not-present page [4005007.702570] PGD 0 P4D 0 [4005007.702576] Oops: 0010 [#1] SMP NOPTI [4005007.702581] CPU: 4 PID: 62563 Comm: cat Tainted: G OE 5.15.0-43-generic #46-Ubunt u [4005007.702590] RIP: 0010:0x0 [4005007.702598] Code: Unable to access opcode bytes at RIP 0xffffffffffffffd6. [4005007.702600] RSP: 0018:ffffa82b46d27da0 EFLAGS: 00010206 [4005007.702605] RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffa82b46d27e68 [4005007.702609] RDX: 0000000000000001 RSI: 0000000000000000 RDI: ffff9940656e0000 [4005007.702612] RBP: ffffa82b46d27dd8 R08: 0000000000000000 R09: ffff994060c07980 [4005007.702615] R10: 0000000000020000 R11: 0000000000000000 R12: 00007f5e06753000 [4005007.702618] R13: ffff9940656e0000 R14: ffffa82b46d27e68 R15: 00007f5e06753000 [4005007.702622] FS: 00007f5e0755b740(0000) GS:ffff99479d300000(0000) knlGS:0000000000000000 [4005007.702626] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [4005007.702629] CR2: ffffffffffffffd6 CR3: 00000003253fc000 CR4: 00000000003506e0 [4005007.702633] Call Trace: [4005007.702636] <TASK> [4005007.702640] amdgpu_debugfs_regs_smc_read+0xb0/0x120 [amdgpu] [4005007.703002] full_proxy_read+0x5c/0x80 [4005007.703011] vfs_read+0x9f/0x1a0 [4005007.703019] ksys_read+0x67/0xe0 [4005007.703023] __x64_sys_read+0x19/0x20 [4005007.703028] do_syscall_64+0x5c/0xc0 [4005007.703034] ? do_user_addr_fault+0x1e3/0x670 [4005007.703040] ? exit_to_user_mode_prepare+0x37/0xb0 [4005007.703047] ? irqentry_exit_to_user_mode+0x9/0x20 [4005007.703052] ? irqentry_exit+0x19/0x30 [4005007.703057] ? exc_page_fault+0x89/0x160 [4005007.703062] ? asm_exc_page_fault+0x8/0x30 [4005007.703068] entry_SYSCALL_64_after_hwframe+0x44/0xae [4005007.703075] RIP: 0033:0x7f5e07672992 [4005007.703079] Code: c0 e9 b2 fe ff ff 50 48 8d 3d fa b2 0c 00 e8 c5 1d 02 00 0f 1f 44 00 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 0f 05 <48> 3d 00 f0 ff ff 77 56 c3 0f 1f 44 00 00 48 83 e c 28 48 89 54 24 [4005007.703083] RSP: 002b:00007ffe03097898 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 [4005007.703088] RAX: ffffffffffffffda RBX: 0000000000020000 RCX: 00007f5e07672992 [4005007.703091] RDX: 0000000000020000 RSI: 00007f5e06753000 RDI: 0000000000000003 [4005007.703094] RBP: 00007f5e06753000 R08: 00007f5e06752010 R09: 00007f5e06752010 [4005007.703096] R10: 0000000000000022 R11: 0000000000000246 R12: 0000000000022000 [4005007.703099] R13: 0000000000000003 R14: 0000000000020000 R15: 0000000000020000 [4005007.703105] </TASK> [4005007.703107] Modules linked in: nf_tables libcrc32c nfnetlink algif_hash af_alg binfmt_misc nls_ iso8859_1 ipmi_ssif ast intel_rapl_msr intel_rapl_common drm_vram_helper drm_ttm_helper amd64_edac t tm edac_mce_amd kvm_amd ccp mac_hid k10temp kvm acpi_ipmi ipmi_si rapl sch_fq_codel ipmi_devintf ipm i_msghandler msr parport_pc ppdev lp parport mtd pstore_blk efi_pstore ramoops pstore_zone reed_solo mon ip_tables x_tables autofs4 ib_uverbs ib_core amdgpu(OE) amddrm_ttm_helper(OE) amdttm(OE) iommu_v 2 amd_sched(OE) amdkcl(OE) drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops cec rc_core drm igb ahci xhci_pci libahci i2c_piix4 i2c_algo_bit xhci_pci_renesas dca [4005007.703184] CR2: 0000000000000000 [4005007.703188] ---[ en ---truncated---
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
CWE-476
134c704f-9b21-4f2e-91b3-4a467353bcc0
CWE-476

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