CVE-2022-49830

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

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.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.