CVE-2022-49827: linux kernel Null Dereference — Fix

Description

In the Linux kernel, the following vulnerability has been resolved: drm: Fix potential null-ptr-deref in drm_vblank_destroy_worker() drm_vblank_init() call drmm_add_action_or_reset() with drm_vblank_init_release() as action. If __drmm_add_action() failed, will directly call drm_vblank_init_release() with the vblank whose worker is NULL. As the resule, a null-ptr-deref will happen in kthread_destroy_worker(). Add the NULL check before calling drm_vblank_destroy_worker(). BUG: null-ptr-deref KASAN: null-ptr-deref in range [0x0000000000000068-0x000000000000006f] CPU: 5 PID: 961 Comm: modprobe Not tainted 6.0.0-11331-gd465bff130bf-dirty RIP: 0010:kthread_destroy_worker+0x25/0xb0 Call Trace: <TASK> drm_vblank_init_release+0x124/0x220 [drm] ? drm_crtc_vblank_restore+0x8b0/0x8b0 [drm] __drmm_add_action_or_reset+0x41/0x50 [drm] drm_vblank_init+0x282/0x310 [drm] vkms_init+0x35f/0x1000 [vkms] ? 0xffffffffc4508000 ? lock_is_held_type+0xd7/0x130 ? __kmem_cache_alloc_node+0x1c2/0x2b0 ? lock_is_held_type+0xd7/0x130 ? 0xffffffffc4508000 do_one_initcall+0xd0/0x4f0 ... do_syscall_64+0x35/0x80 entry_SYSCALL_64_after_hwframe+0x46/0xb0

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CVSS v3.1 Score

5.5

MEDIUM

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Weakness Type (CWE)

CWE-476 CWE-476

Affected Products

Vendor	Product	Versions
linux	linux_kernel	5.9 — 5.10.156
linux	linux_kernel	5.11 — 5.15.80
linux	linux_kernel	5.16 — 6.0.10
linux	linux_kernel	All
linux	linux_kernel	All
linux	linux_kernel	All
linux	linux_kernel	All
linux	linux_kernel	All

References

Advisories & Patches

https://git.kernel.org/stable/c/1d160dfb3fdf11ba9447e862c548447f91f4e74a https://git.kernel.org/stable/c/3acd2016421b2e628acad65495d15493bf7a3bc3 https://git.kernel.org/stable/c/4979524f5a2a8210e87fde2f642b0dc060860821 https://git.kernel.org/stable/c/e884a6c2d49a6c12761e5bed851e9fe93bd923a1

Frequently Asked Questions

What is CVE-2022-49827? +

In the Linux kernel, the following vulnerability has been resolved: drm: Fix potential null-ptr-deref in drm_vblank_destroy_worker() drm_vblank_init() call drmm_add_action_or_reset() with drm_vblank_init_release() as action. If __drmm_add_action() failed, will directly call drm_vblank_init_release() with the vblank whose worker is NULL. As the resule, a null-ptr-deref will happen in kthread_destroy_worker(). Add the NULL check before calling drm_vblank_destroy_worker(). BUG: null-ptr-deref KASAN: null-ptr-deref in range [0x0000000000000068-0x000000000000006f] CPU: 5 PID: 961 Comm: modprobe Not tainted 6.0.0-11331-gd465bff130bf-dirty RIP: 0010:kthread_destroy_worker+0x25/0xb0 Call Trace: <TASK> drm_vblank_init_release+0x124/0x220 [drm] ? drm_crtc_vblank_restore+0x8b0/0x8b0 [drm] __drmm_add_action_or_reset+0x41/0x50 [drm] drm_vblank_init+0x282/0x310 [drm] vkms_init+0x35f/0x1000 [vkms] ? 0xffffffffc4508000 ? lock_is_held_type+0xd7/0x130 ? __kmem_cache_alloc_node+0x1c2/0x2b0 ? lock_is_held_type+0xd7/0x130 ? 0xffffffffc4508000 do_one_initcall+0xd0/0x4f0 ... do_syscall_64+0x35/0x80 entry_SYSCALL_64_after_hwframe+0x46/0xb0 It has a CVSS v3.1 base score of 5.5 (MEDIUM).

How severe is CVE-2022-49827? +

CVE-2022-49827 has a CVSS v3.1 score of 5.5 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance.

What products are affected by CVE-2022-49827? +

CVE-2022-49827 affects products from linux, specifically: linux_kernel. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2022-49827? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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CVE-2022-49827