io_uring/net: commit partial buffers on retry

Summary

In the Linux kernel, the following vulnerability has been resolved: io_uring/net: commit partial buffers on retry Ring provided buffers are potentially only valid within the single execution context in which they were acquired. io_uring deals with this and invalidates them on retry. But on the networking side, if MSG_WAITALL is set, or if the socket is of the streaming type and too little was processed, then it will hang on to the buffer rather than recycle or commit it. This is problematic for two reasons: 1) If someone unregisters the provided buffer ring before a later retry, then the req->buf_list will no longer be valid. 2) If multiple sockers are using the same buffer group, then multiple receives can consume the same memory. This can cause data corruption in the application, as either receive could land in the same userspace buffer. Fix this by disallowing partial retries from pinning a provided buffer across multiple executions, if ring provided buffers are used.

Timeline

1. Sep 4, 2025, 3:33 PM UTCCVE published
2. Oct 15, 2026, 9:52 PM UTCCISA SSVC assessment

   Exploitation: none · Automatable: no · Technical impact: total

3. Oct 15, 2026, 10:02 PM UTCRecord last updated

Affected versions

• Linux Linux

  From c56e022c0a27142b7b59ae6bdf45f86bf4b298a1 · fixed in 3b53dc1c641f2884d4750fc25aaf6c36b90db606; From c56e022c0a27142b7b59ae6bdf45f86bf4b298a1 · fixed in fe9da1812f8697a38f7e30991d568ec199e16059; From c56e022c0a27142b7b59ae6bdf45f86bf4b298a1 · fixed in 21a4ddb0f5e933f372808c10b9ac704505751bb1; From c56e022c0a27142b7b59ae6bdf45f86bf4b298a1 · fixed in 2eb7937b5fc7fcd90eab7bebb0181214b61b9283; From c56e022c0a27142b7b59ae6bdf45f86bf4b298a1 · fixed in 41b70df5b38bc80967d2e0ed55cc3c3896bba781

• Linux Linux

  6.4

• KernelLinux

  From 6.4.0 · fixed in 6.6.103; From 6.7.0 · fixed in 6.12.44; From 6.13.0 · fixed in 6.15.11; From 6.16.0 · fixed in 6.16.2

References 5