| commit | b1b40873b95a40789a541ebf0fc9b1ff42d90903 | [log] [tgz] |
|---|---|---|
| author | Davide Caratti <[email protected]> | Tue May 16 22:00:40 2023 +0300 |
| committer | Arnav Kansal <[email protected]> | Fri Jun 09 22:59:52 2023 +0000 |
| tree | 9dc719ad72c6985a8f5a25f73d55c9f11a030c3a | |
| parent | 03b0bcab25e4b4da8647c53f1a851d8eac95dda5 [diff] |
act_mirred: use the backlog for nested calls to mirred ingress [ Upstream commit ca22da2fbd693b54dc8e3b7b54ccc9f7e9ba3640 ] William reports kernel soft-lockups on some OVS topologies when TC mirred egress->ingress action is hit by local TCP traffic [1]. The same can also be reproduced with SCTP (thanks Xin for verifying), when client and server reach themselves through mirred egress to ingress, and one of the two peers sends a "heartbeat" packet (from within a timer). Enqueueing to backlog proved to fix this soft lockup; however, as Cong noticed [2], we should preserve - when possible - the current mirred behavior that counts as "overlimits" any eventual packet drop subsequent to the mirred forwarding action [3]. A compromise solution might use the backlog only when tcf_mirred_act() has a nest level greater than one: change tcf_mirred_forward() accordingly. Also, add a kselftest that can reproduce the lockup and verifies TC mirred ability to account for further packet drops after TC mirred egress->ingress (when the nest level is 1). [1] https://lore.kernel.org/netdev/33dc43f587ec1388ba456b4915c75f02a8aae226.1663945716.git.dcaratti@redhat.com/ [2] https://lore.kernel.org/netdev/Y0w%[email protected]/ [3] such behavior is not guaranteed: for example, if RPS or skb RX timestamping is enabled on the mirred target device, the kernel can defer receiving the skb and return NET_RX_SUCCESS inside tcf_mirred_forward(). BUG=b/261837566 RELEASE_NOTE=Fixed CVE-2022-4269 in the Linux kernel. Reported-by: William Zhao <[email protected]> CC: Xin Long <[email protected]> Change-Id: Id9ca648d87513b96a6ca2a1dfe939e04a0dd4c24 Signed-off-by: Davide Caratti <[email protected]> Reviewed-by: Marcelo Ricardo Leitner <[email protected]> Acked-by: Jamal Hadi Salim <[email protected]> Signed-off-by: Paolo Abeni <[email protected]> [DP: adjusted context for linux-5.10.y] Signed-off-by: Dragos-Marian Panait <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> Reviewed-on: https://cos-review.googlesource.com/c/third_party/kernel/+/50520 Tested-by: Cusky Presubmit Bot <[email protected]> Reviewed-by: Meena Shanmugam <[email protected]>