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authorMatthieu Baerts (NGI0) <matttbe@kernel.org>2024-08-28 08:14:33 +0200
committerPaolo Abeni <pabeni@redhat.com>2024-08-29 10:39:50 +0200
commit9366922adc6a71378ca01f898c41be295309f044 (patch)
tree74dfbdc8023acc3c5b1b8485d0e2561fd7bd9341 /net/mptcp
parent58e1b66b4e4b8a602d3f2843e8eba00a969ecce2 (diff)
mptcp: pm: fix ID 0 endp usage after multiple re-creations
'local_addr_used' and 'add_addr_accepted' are decremented for addresses not related to the initial subflow (ID0), because the source and destination addresses of the initial subflows are known from the beginning: they don't count as "additional local address being used" or "ADD_ADDR being accepted". It is then required not to increment them when the entrypoint used by the initial subflow is removed and re-added during a connection. Without this modification, this entrypoint cannot be removed and re-added more than once. Reported-by: Arınç ÜNAL <arinc.unal@arinc9.com> Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/512 Fixes: 3ad14f54bd74 ("mptcp: more accurate MPC endpoint tracking") Reported-by: syzbot+455d38ecd5f655fc45cf@syzkaller.appspotmail.com Closes: https://lore.kernel.org/00000000000049861306209237f4@google.com Cc: stable@vger.kernel.org Tested-by: Arınç ÜNAL <arinc.unal@arinc9.com> Reviewed-by: Mat Martineau <martineau@kernel.org> Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Diffstat (limited to 'net/mptcp')
-rw-r--r--net/mptcp/pm_netlink.c7
1 files changed, 5 insertions, 2 deletions
diff --git a/net/mptcp/pm_netlink.c b/net/mptcp/pm_netlink.c
index 3ff273e219f2..a93450ded50a 100644
--- a/net/mptcp/pm_netlink.c
+++ b/net/mptcp/pm_netlink.c
@@ -615,12 +615,13 @@ subflow:
fullmesh = !!(local.flags & MPTCP_PM_ADDR_FLAG_FULLMESH);
- msk->pm.local_addr_used++;
__clear_bit(local.addr.id, msk->pm.id_avail_bitmap);
/* Special case for ID0: set the correct ID */
if (local.addr.id == msk->mpc_endpoint_id)
local.addr.id = 0;
+ else /* local_addr_used is not decr for ID 0 */
+ msk->pm.local_addr_used++;
nr = fill_remote_addresses_vec(msk, &local.addr, fullmesh, addrs);
if (nr == 0)
@@ -750,7 +751,9 @@ static void mptcp_pm_nl_add_addr_received(struct mptcp_sock *msk)
spin_lock_bh(&msk->pm.lock);
if (sf_created) {
- msk->pm.add_addr_accepted++;
+ /* add_addr_accepted is not decr for ID 0 */
+ if (remote.id)
+ msk->pm.add_addr_accepted++;
if (msk->pm.add_addr_accepted >= add_addr_accept_max ||
msk->pm.subflows >= subflows_max)
WRITE_ONCE(msk->pm.accept_addr, false);