CVE-2026-52935xfrm: espintcp: do not reuse an in-progress partial send

Official description

In the Linux kernel, the following vulnerability has been resolved: xfrm: espintcp: do not reuse an in-progress partial send espintcp keeps a single in-flight transmit in ctx->partial. Before building a new sk_msg, espintcp_sendmsg() first tries to flush that state through espintcp_push_msgs(). For blocking callers, espintcp_push_msgs() may return success even when the previous partial send is still pending. espintcp_sendmsg() would then reinitialize emsg->skmsg and reuse ctx->partial while the old transfer still owns that state. Do not rebuild the send message when ctx->partial is still in progress. If espintcp_push_msgs() returns with emsg->len still set, fail the new send instead of overwriting the live partial state. This is a memory-safety fix: reusing the live partial-send state can leave a stale offset attached to a new sk_msg and lead to an out-of- bounds read in the send path. tcp_sendmsg_locked() already handles waiting for send buffer memory, so the fix here is just to preserve espintcp's one-message-at-a-time transmit state.

Affected packages & fixed versions

Affected products (as reported)

References

• https://git.kernel.org/stable/c/6564e9c7af7e1dc7bfe7f3093b728abe484d7630
• https://git.kernel.org/stable/c/1777ceac4bea5e568a5ad44b7f9bb219c1db21b6
• https://git.kernel.org/stable/c/8c6c691bf062dc0753a139a4ab8cb92a70fcf8f3
• https://git.kernel.org/stable/c/aa82a078f70f7ff88ba7d1017134e79d1ac140f2
• https://git.kernel.org/stable/c/ba21439302db9a82fe4edbed1e38a97271529421
• https://git.kernel.org/stable/c/f9b38a8fbfa07f1deaf7ee1eb38fa8b21ea13990
• https://git.kernel.org/stable/c/37487d55bf3300e3d2c1368da5c2bd3e3834ea4f
• https://git.kernel.org/stable/c/c381039ade2e161ab08c0eda73c4f8b9a7115928