CVE-2022-50838

Description

In the Linux kernel, the following vulnerability has been resolved: net: stream: purge sk_error_queue in sk_stream_kill_queues() Changheon Lee reported TCP socket leaks, with a nice repro. It seems we leak TCP sockets with the following sequence: 1) SOF_TIMESTAMPING_TX_ACK is enabled on the socket. Each ACK will cook an skb put in error queue, from __skb_tstamp_tx(). __skb_tstamp_tx() is using skb_clone(), unless SOF_TIMESTAMPING_OPT_TSONLY was also requested. 2) If the application is also using MSG_ZEROCOPY, then we put in the error queue cloned skbs that had a struct ubuf_info attached to them. Whenever an struct ubuf_info is allocated, sock_zerocopy_alloc() does a sock_hold(). As long as the cloned skbs are still in sk_error_queue, socket refcount is kept elevated. 3) Application closes the socket, while error queue is not empty. Since tcp_close() no longer purges the socket error queue, we might end up with a TCP socket with at least one skb in error queue keeping the socket alive forever. This bug can be (ab)used to consume all kernel memory and freeze the host. We need to purge the error queue, with proper synchronization against concurrent writers.

PUBLISHED Reserved 2025-12-30 | Published 2025-12-30 | Updated 2025-12-30 | Assigner Linux

Product status

References

git.kernel.org/...c/c8c1eec578a9ae2dc8f14a1846942a0b7bf29d1d

git.kernel.org/...c/bab542cf56fc174c8447c00b73be99ffd66d2d39

git.kernel.org/...c/6f00bd0402a1e3d2d556afba57c045bd7931e4d3

git.kernel.org/...c/4f1d37ff4226eb99d6b69e9f4518e279e1a851bf

git.kernel.org/...c/9062493811676ee0efe6c74d98f00ca38c4e17d4

git.kernel.org/...c/9da204cd67c4fe97e8aa465d10d5c2e7076f7f42

git.kernel.org/...c/8c330c36b3970d0917f48827fa6c7a9c75aa4602

git.kernel.org/...c/b458d349f8753f666233828ebd30df6f100cf7d5

git.kernel.org/...c/e0c8bccd40fc1c19e1d246c39bcf79e357e1ada3

cve.org (CVE-2022-50838)

nvd.nist.gov (CVE-2022-50838)

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