diff mbox series

[net,1/2] mptcp: more strict state checking for acks

Message ID 5566ba1c4409a652440d84ff49b99e58ca998a0e.1610471474.git.pabeni@redhat.com (mailing list archive)
State Accepted
Commit 20bc80b6f582ad1151c52ca09ab66b472768c9c8
Delegated to: Netdev Maintainers
Headers show
Series mptcp: a couple of fixes | expand

Checks

Context Check Description
netdev/cover_letter success Link
netdev/fixes_present success Link
netdev/patch_count success Link
netdev/tree_selection success Clearly marked for net
netdev/subject_prefix success Link
netdev/cc_maintainers warning 2 maintainers not CCed: matthieu.baerts@tessares.net mathew.j.martineau@linux.intel.com
netdev/source_inline success Was 0 now: 0
netdev/verify_signedoff success Link
netdev/module_param success Was 0 now: 0
netdev/build_32bit success Errors and warnings before: 2 this patch: 2
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/verify_fixes success Link
netdev/checkpatch warning WARNING: line length of 92 exceeds 80 columns
netdev/build_allmodconfig_warn success Errors and warnings before: 2 this patch: 2
netdev/header_inline success Link
netdev/stable success Stable not CCed

Commit Message

Paolo Abeni Jan. 12, 2021, 5:25 p.m. UTC
Syzkaller found a way to trigger division by zero
in mptcp_subflow_cleanup_rbuf().

The current checks implemented into tcp_can_send_ack()
are too week, let's be more accurate.

Reported-by: Christoph Paasch <cpaasch@apple.com>
Fixes: ea4ca586b16f ("mptcp: refine MPTCP-level ack scheduling")
Fixes: fd8976790a6c ("mptcp: be careful on MPTCP-level ack.")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
---
 net/mptcp/protocol.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Mat Martineau Jan. 12, 2021, 9:37 p.m. UTC | #1
On Tue, 12 Jan 2021, Paolo Abeni wrote:

> Syzkaller found a way to trigger division by zero
> in mptcp_subflow_cleanup_rbuf().
>
> The current checks implemented into tcp_can_send_ack()
> are too week, let's be more accurate.
>
> Reported-by: Christoph Paasch <cpaasch@apple.com>
> Fixes: ea4ca586b16f ("mptcp: refine MPTCP-level ack scheduling")
> Fixes: fd8976790a6c ("mptcp: be careful on MPTCP-level ack.")
> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
> ---
> net/mptcp/protocol.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>

Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>

--
Mat Martineau
Intel
diff mbox series

Patch

diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
index 6628d8d74203..2ff8c7caf74f 100644
--- a/net/mptcp/protocol.c
+++ b/net/mptcp/protocol.c
@@ -427,7 +427,7 @@  static bool mptcp_subflow_active(struct mptcp_subflow_context *subflow)
 static bool tcp_can_send_ack(const struct sock *ssk)
 {
 	return !((1 << inet_sk_state_load(ssk)) &
-	       (TCPF_SYN_SENT | TCPF_SYN_RECV | TCPF_TIME_WAIT | TCPF_CLOSE));
+	       (TCPF_SYN_SENT | TCPF_SYN_RECV | TCPF_TIME_WAIT | TCPF_CLOSE | TCPF_LISTEN));
 }
 
 static void mptcp_send_ack(struct mptcp_sock *msk)