CVE-2022-49830
Description
From CVE.org
In the Linux kernel, the following vulnerability has been resolved: drm/drv: Fix potential memory leak in drm_dev_init() drm_dev_init() will add drm_dev_init_release() as a callback. When drmm_add_action() failed, the release function won't be added. As the result, the ref cnt added by device_get() in drm_dev_init() won't be put by drm_dev_init_release(), which leads to the memleak. Use drmm_add_action_or_reset() instead of drmm_add_action() to prevent memleak. unreferenced object 0xffff88810bc0c800 (size 2048): comm "modprobe", pid 8322, jiffies 4305809845 (age 15.292s) hex dump (first 32 bytes): e8 cc c0 0b 81 88 ff ff ff ff ff ff 00 00 00 00 ................ 20 24 3c 0c 81 88 ff ff 18 c8 c0 0b 81 88 ff ff $<............. backtrace: [<000000007251f72d>] __kmalloc+0x4b/0x1c0 [<0000000045f21f26>] platform_device_alloc+0x2d/0xe0 [<000000004452a479>] platform_device_register_full+0x24/0x1c0 [<0000000089f4ea61>] 0xffffffffa0736051 [<00000000235b2441>] do_one_initcall+0x7a/0x380 [<0000000001a4a177>] do_init_module+0x5c/0x230 [<000000002bf8a8e2>] load_module+0x227d/0x2420 [<00000000637d6d0a>] __do_sys_finit_module+0xd5/0x140 [<00000000c99fc324>] do_syscall_64+0x3f/0x90 [<000000004d85aa77>] entry_SYSCALL_64_after_hwframe+0x63/0xcd
Statement
This patch fixes a potential memory leak in drm_dev_init() caused by failure in drmm_add_action(). If this call fails, the release function is not registered, and the reference count incremented by device_get() is never released — leading to a memory leak. Replacing drmm_add_action() with drmm_add_action_or_reset() ensures cleanup is triggered correctly on failure. Without the fix, failing to register a cleanup handler can result in unreferenced memory being leaked during device initialization, especially during module load via modprobe.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 2.3 | 5.5 | N/A |
| Attack Vector | Local | Local | N/A |
| Attack Complexity | Low | Low | N/A |
| Privileges Required | High | Low | N/A |
| User Interaction | None | None | N/A |
| Scope | Unchanged | Unchanged | N/A |
| Confidentiality | None | None | N/A |
| Integrity Impact | None | None | N/A |
| Availability Impact | Low | High | N/A |
Vector
Red Hat: CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:L
NVD: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Frequently Asked Questions
Not sure what something means? Check out our Security Glossary.
Want to get errata notifications? Sign up here.
