On 1/22/26 15:13, Stefano Brivio wrote:

Commit 90287c2a774e ("tcp: Register fds with epoll at flow creation") added a call to flow_epoll_set() in tcp_flow_migrate_target() without checking for the error code.

As Laurent explains, that's harmless, as tcp_flow_migrate_target_ext() will clean up the flow anyway, and we'll just uselessly call flow_hash_insert() before removing it again.

But Coverity Scan complains about the unchecked return code, so check it, skip flow_hash_insert() in that case, and explain in comments why we don't have to do anything else.

Signed-off-by: Stefano Brivio --- tcp.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/tcp.c b/tcp.c index 6a26826..0a6b7ff 100644 --- a/tcp.c +++ b/tcp.c @@ -3684,17 +3684,19 @@ int tcp_flow_migrate_target(struct ctx *c, int fd)

if ((rc = tcp_flow_repair_socket(c, conn))) { flow_err(flow, "Can't set up socket: %s, drop", strerror_(-rc)); - /* Can't leave the flow in an incomplete state */ - FLOW_ACTIVATE(conn); - return 0; + goto out; }

flow_epollid_set(&conn->f, EPOLLFD_ID_DEFAULT); - flow_epoll_set(&conn->f, EPOLL_CTL_ADD, 0, conn->sock, !TAPSIDE(conn)); + if (flow_epoll_set(&conn->f, EPOLL_CTL_ADD, 0, conn->sock, + !TAPSIDE(conn))) + goto out; /* tcp_flow_migrate_target_ext() will clean this up */

flow_hash_insert(c, TAP_SIDX(conn)); - FLOW_ACTIVATE(conn);

+out: + /* Never leave the flow in an incomplete state */ + FLOW_ACTIVATE(conn); return 0; }

Reviewed-by: Laurent Vivier