drm/drv: Fix potential memory leak in drm_dev_init()

Overview

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

Affected

• Linux >= 2cbf7fc6718b9443ecd6261308c6348d8ffcccae < c47a823ea186263ab69cfb665327b7f72cb5e779
• Linux >= 2cbf7fc6718b9443ecd6261308c6348d8ffcccae < 07e56de8766fe5be67252596244b84ac0ec0de91
• Linux >= 2cbf7fc6718b9443ecd6261308c6348d8ffcccae < bd8d1335e6e70a396094ef98913b513140c0b86b
• Linux >= 2cbf7fc6718b9443ecd6261308c6348d8ffcccae < ff963634f7b2e0dc011349abb3fb81a0d074f443
• Linux 5.8

Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.