Description
In the Linux kernel, the following vulnerability has been resolved: sctp: drop a chunk if its transport was removed sctp_rcv() resolves the transport once per packet and leaves it in chunk->transport. The lookup reference, or the one sctp_add_backlog() takes if the socket is owned by userspace, keeps it around until the chunk has been processed. An authenticated ASCONF DEL-IP can remove it in the meantime. sctp_assoc_rm_peer() takes the transport out of the association and calls sctp_transport_free(), which tags it dead and drops the reference the association held. There is a window on both paths: the packet can sit on the socket backlog, and on the direct path the lookup completes before bh_lock_sock(). The DATA chunk in that packet puts the removed transport back into asoc->peer.last_data_from. Once the packet is done that reference goes away and the transport is freed by RCU, so the next delayed SACK carries the pointer into the SACK chunk and sctp_outq_select_transport() reads the freed transport's state. Drop the chunk in sctp_inq_push(), next to the existing rcvr->dead check. Both paths reach it with the association's socket lock held. The peer retransmits it.
Affected products
Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.
Linux Linux
Default version status: unaffected
1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to < 3fc072e7cb4a0ff251d13cfc2d24f62489cd9386affected1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to < d7cb5ad832095dc4becfdb2a36007ffd50e49fb0affected1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to < 0422b092a3d43ca462932ff9f747731ca078d1d4affected1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to < 928fd7920ba37cc5637a211b9be979083413a2faaffected1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to < c6c86a5e62a4fec36692ddd64b9144b660f71f96affected1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to < 1035bdef1efb9b1076d1a57b81e08c637ff08eccaffected1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to < 3537961df2163258bddc230db0e18dc14e925ea6affected1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to < 03a9d10ecf71f54b2af8020935f2033d4a132be5affected
Linux Linux
Default version status: affected
2.6.12affected0 to < 2.6.12unaffected5.10.270 to ≤ 5.10.*unaffected5.15.221 to ≤ 5.15.*unaffected6.1.188 to ≤ 6.1.*unaffected6.6.157 to ≤ 6.6.*unaffected6.12.109 to ≤ 6.12.*unaffected6.18.50 to ≤ 6.18.*unaffected7.2.4 to ≤ 7.2.*unaffected7.3 to ≤ *unaffected
References
- https://git.kernel.org/stable/c/3fc072e7cb4a0ff251d13cfc2d24f62489cd9386 ↗
- https://git.kernel.org/stable/c/d7cb5ad832095dc4becfdb2a36007ffd50e49fb0 ↗
- https://git.kernel.org/stable/c/0422b092a3d43ca462932ff9f747731ca078d1d4 ↗
- https://git.kernel.org/stable/c/928fd7920ba37cc5637a211b9be979083413a2fa ↗
- https://git.kernel.org/stable/c/c6c86a5e62a4fec36692ddd64b9144b660f71f96 ↗
- https://git.kernel.org/stable/c/1035bdef1efb9b1076d1a57b81e08c637ff08ecc ↗
- https://git.kernel.org/stable/c/3537961df2163258bddc230db0e18dc14e925ea6 ↗
- https://git.kernel.org/stable/c/03a9d10ecf71f54b2af8020935f2033d4a132be5 ↗