CVE-2024-35995

Published May 20, 2024

Last updated 9 months ago

Overview

Description
In the Linux kernel, the following vulnerability has been resolved: ACPI: CPPC: Use access_width over bit_width for system memory accesses To align with ACPI 6.3+, since bit_width can be any 8-bit value, it cannot be depended on to be always on a clean 8b boundary. This was uncovered on the Cobalt 100 platform. SError Interrupt on CPU26, code 0xbe000011 -- SError CPU: 26 PID: 1510 Comm: systemd-udevd Not tainted 5.15.2.1-13 #1 Hardware name: MICROSOFT CORPORATION, BIOS MICROSOFT CORPORATION pstate: 62400009 (nZCv daif +PAN -UAO +TCO -DIT -SSBS BTYPE=--) pc : cppc_get_perf_caps+0xec/0x410 lr : cppc_get_perf_caps+0xe8/0x410 sp : ffff8000155ab730 x29: ffff8000155ab730 x28: ffff0080139d0038 x27: ffff0080139d0078 x26: 0000000000000000 x25: ffff0080139d0058 x24: 00000000ffffffff x23: ffff0080139d0298 x22: ffff0080139d0278 x21: 0000000000000000 x20: ffff00802b251910 x19: ffff0080139d0000 x18: ffffffffffffffff x17: 0000000000000000 x16: ffffdc7e111bad04 x15: ffff00802b251008 x14: ffffffffffffffff x13: ffff013f1fd63300 x12: 0000000000000006 x11: ffffdc7e128f4420 x10: 0000000000000000 x9 : ffffdc7e111badec x8 : ffff00802b251980 x7 : 0000000000000000 x6 : ffff0080139d0028 x5 : 0000000000000000 x4 : ffff0080139d0018 x3 : 00000000ffffffff x2 : 0000000000000008 x1 : ffff8000155ab7a0 x0 : 0000000000000000 Kernel panic - not syncing: Asynchronous SError Interrupt CPU: 26 PID: 1510 Comm: systemd-udevd Not tainted 5.15.2.1-13 #1 Hardware name: MICROSOFT CORPORATION, BIOS MICROSOFT CORPORATION Call trace: dump_backtrace+0x0/0x1e0 show_stack+0x24/0x30 dump_stack_lvl+0x8c/0xb8 dump_stack+0x18/0x34 panic+0x16c/0x384 add_taint+0x0/0xc0 arm64_serror_panic+0x7c/0x90 arm64_is_fatal_ras_serror+0x34/0xa4 do_serror+0x50/0x6c el1h_64_error_handler+0x40/0x74 el1h_64_error+0x7c/0x80 cppc_get_perf_caps+0xec/0x410 cppc_cpufreq_cpu_init+0x74/0x400 [cppc_cpufreq] cpufreq_online+0x2dc/0xa30 cpufreq_add_dev+0xc0/0xd4 subsys_interface_register+0x134/0x14c cpufreq_register_driver+0x1b0/0x354 cppc_cpufreq_init+0x1a8/0x1000 [cppc_cpufreq] do_one_initcall+0x50/0x250 do_init_module+0x60/0x27c load_module+0x2300/0x2570 __do_sys_finit_module+0xa8/0x114 __arm64_sys_finit_module+0x2c/0x3c invoke_syscall+0x78/0x100 el0_svc_common.constprop.0+0x180/0x1a0 do_el0_svc+0x84/0xa0 el0_svc+0x2c/0xc0 el0t_64_sync_handler+0xa4/0x12c el0t_64_sync+0x1a4/0x1a8 Instead, use access_width to determine the size and use the offset and width to shift and mask the bits to read/write out. Make sure to add a check for system memory since pcc redefines the access_width to subspace id. If access_width is not set, then fall back to using bit_width. [ rjw: Subject and changelog edits, comment adjustments ]
Source
416baaa9-dc9f-4396-8d5f-8c081fb06d67
NVD status
Analyzed
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