CVE-2022-50434

In the Linux kernel, the following vulnerability has been resolved:

blk-mq: fix possible memleak when register hctx failed

Theres issue as follows when do fault injection test: unreferenced object 0xffff888132a9f400 (size 512): comm insmod, pid 308021, jiffies 4324277909 (age 509.733s) hex dump (first 32 bytes): 00 00 00 00 00 00 00 00 08 f4 a9 32 81 88 ff ff ………..2…. 08 f4 a9 32 81 88 ff ff 00 00 00 00 00 00 00 00 …2………… backtrace: [<00000000e8952bb4>] kmalloc_node_trace+0x22/0xa0 [<00000000f9980e0f>] blk_mq_alloc_and_init_hctx+0x3f1/0x7e0 [<000000002e719efa>] blk_mq_realloc_hw_ctxs+0x1e6/0x230 [<000000004f1fda40>] blk_mq_init_allocated_queue+0x27e/0x910 [<00000000287123ec>] __blk_mq_alloc_disk+0x67/0xf0 [<00000000a2a34657>] 0xffffffffa2ad310f [<00000000b173f718>] 0xffffffffa2af824a [<0000000095a1dabb>] do_one_initcall+0x87/0x2a0 [<00000000f32fdf93>] do_init_module+0xdf/0x320 [<00000000cbe8541e>] load_module+0x3006/0x3390 [<0000000069ed1bdb>] __do_sys_finit_module+0x113/0x1b0 [<00000000a1a29ae8>] do_syscall_64+0x35/0x80 [<000000009cd878b0>] entry_SYSCALL_64_after_hwframe+0x46/0xb0

Fault injection context as follows: kobject_add blk_mq_register_hctx blk_mq_sysfs_register blk_register_queue device_add_disk null_add_dev.part.0 [null_blk]

As blk_mq_register_hctx may already add some objects when failed halfway, but there isnt do fallback, caller dont know which objects add failed. To solve above issue just do fallback when add objects failed halfway in blk_mq_register_hctx.

Affected Software

References

• https://git.kernel.org/stable/c/02bc8bc6eab03c84373281b85cb6e98747172ff7
• https://git.kernel.org/stable/c/33e8a3f61814ea30615d0fafaf50477975d6c1ca
• https://git.kernel.org/stable/c/4b7a21c57b14fbcd0e1729150189e5933f5088e9
• https://git.kernel.org/stable/c/4b7fafa5f39b15c3a6ca3b95e534d05d6904cc95
• https://git.kernel.org/stable/c/654870789c3c1b9763316ef1c71d7a449127b175
• https://git.kernel.org/stable/c/87fd18016a47ea8ae12641377a390172c4aa97a7
• https://git.kernel.org/stable/c/cb186eb47fb9dd327bdefa15f0c5fc55c53a40dd
• https://git.kernel.org/stable/c/e8022da1fa2fdf2fa204b445dd3354e7a66d085a
• https://git.kernel.org/stable/c/eff45bfbc25a2509a6362dea6e699e14083c693c