CVE-2022-49400

Published Feb 26, 2025

Last updated 8 months ago

Overview

Description
In the Linux kernel, the following vulnerability has been resolved: md: Don't set mddev private to NULL in raid0 pers->free In normal stop process, it does like this: do_md_stop | __md_stop (pers->free(); mddev->private=NULL) | md_free (free mddev) __md_stop sets mddev->private to NULL after pers->free. The raid device will be stopped and mddev memory is free. But in reshape, it doesn't free the mddev and mddev will still be used in new raid. In reshape, it first sets mddev->private to new_pers and then runs old_pers->free(). Now raid0 sets mddev->private to NULL in raid0_free. The new raid can't work anymore. It will panic when dereference mddev->private because of NULL pointer dereference. It can panic like this: [63010.814972] kernel BUG at drivers/md/raid10.c:928! [63010.819778] invalid opcode: 0000 [#1] PREEMPT SMP NOPTI [63010.825011] CPU: 3 PID: 44437 Comm: md0_resync Kdump: loaded Not tainted 5.14.0-86.el9.x86_64 #1 [63010.833789] Hardware name: Dell Inc. PowerEdge R6415/07YXFK, BIOS 1.15.0 09/11/2020 [63010.841440] RIP: 0010:raise_barrier+0x161/0x170 [raid10] [63010.865508] RSP: 0018:ffffc312408bbc10 EFLAGS: 00010246 [63010.870734] RAX: 0000000000000000 RBX: ffffa00bf7d39800 RCX: 0000000000000000 [63010.877866] RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffffa00bf7d39800 [63010.884999] RBP: 0000000000000000 R08: fffffa4945e74400 R09: 0000000000000000 [63010.892132] R10: ffffa00eed02f798 R11: 0000000000000000 R12: ffffa00bbc435200 [63010.899266] R13: ffffa00bf7d39800 R14: 0000000000000400 R15: 0000000000000003 [63010.906399] FS: 0000000000000000(0000) GS:ffffa00eed000000(0000) knlGS:0000000000000000 [63010.914485] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [63010.920229] CR2: 00007f5cfbe99828 CR3: 0000000105efe000 CR4: 00000000003506e0 [63010.927363] Call Trace: [63010.929822] ? bio_reset+0xe/0x40 [63010.933144] ? raid10_alloc_init_r10buf+0x60/0xa0 [raid10] [63010.938629] raid10_sync_request+0x756/0x1610 [raid10] [63010.943770] md_do_sync.cold+0x3e4/0x94c [63010.947698] md_thread+0xab/0x160 [63010.951024] ? md_write_inc+0x50/0x50 [63010.954688] kthread+0x149/0x170 [63010.957923] ? set_kthread_struct+0x40/0x40 [63010.962107] ret_from_fork+0x22/0x30 Removing the code that sets mddev->private to NULL in raid0 can fix problem.
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