diff options
| author | Paolo Abeni <pabeni@redhat.com> | 2021-05-27 16:31:37 -0700 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2021-05-28 13:51:39 -0700 |
| commit | b5941f066b4ca331db225a976dae1d6ca8cf0ae3 (patch) | |
| tree | b6fa9bcf8c7680ae478f77f611f2fcf94df7cc13 /net | |
| parent | 44991d61aa120ed3e12f75bb0e0fbd2a84df930d (diff) | |
mptcp: fix sk_forward_memory corruption on retransmission
MPTCP sk_forward_memory handling is a bit special, as such field
is protected by the msk socket spin_lock, instead of the plain
socket lock.
Currently we have a code path updating such field without handling
the relevant lock:
__mptcp_retrans() -> __mptcp_clean_una_wakeup()
Several helpers in __mptcp_clean_una_wakeup() will update
sk_forward_alloc, possibly causing such field corruption, as reported
by Matthieu.
Address the issue providing and using a new variant of blamed function
which explicitly acquires the msk spin lock.
Fixes: 64b9cea7a0af ("mptcp: fix spurious retransmissions")
Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/172
Reported-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Tested-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'net')
| -rw-r--r-- | net/mptcp/protocol.c | 16 |
1 files changed, 15 insertions, 1 deletions
diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index 2bc199549a88..5edc686faff1 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -947,6 +947,10 @@ static void __mptcp_update_wmem(struct sock *sk) { struct mptcp_sock *msk = mptcp_sk(sk); +#ifdef CONFIG_LOCKDEP + WARN_ON_ONCE(!lockdep_is_held(&sk->sk_lock.slock)); +#endif + if (!msk->wmem_reserved) return; @@ -1085,10 +1089,20 @@ out: static void __mptcp_clean_una_wakeup(struct sock *sk) { +#ifdef CONFIG_LOCKDEP + WARN_ON_ONCE(!lockdep_is_held(&sk->sk_lock.slock)); +#endif __mptcp_clean_una(sk); mptcp_write_space(sk); } +static void mptcp_clean_una_wakeup(struct sock *sk) +{ + mptcp_data_lock(sk); + __mptcp_clean_una_wakeup(sk); + mptcp_data_unlock(sk); +} + static void mptcp_enter_memory_pressure(struct sock *sk) { struct mptcp_subflow_context *subflow; @@ -2299,7 +2313,7 @@ static void __mptcp_retrans(struct sock *sk) struct sock *ssk; int ret; - __mptcp_clean_una_wakeup(sk); + mptcp_clean_una_wakeup(sk); dfrag = mptcp_rtx_head(sk); if (!dfrag) { if (mptcp_data_fin_enabled(msk)) { |