Paolo Abeni c886d70286 mptcp: do not queue data on closed subflows ... Dipanjan reported a syzbot splat at close time: WARNING: CPU: 1 PID: 10818 at net/ipv4/af_inet.c:153 inet_sock_destruct+0x6d0/0x8e0 net/ipv4/af_inet.c:153 Modules linked in: uio_ivshmem(OE) uio(E) CPU: 1 PID: 10818 Comm: kworker/1:16 Tainted: G OE 5.19.0-rc6-g2eae0556bb9d #2 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014 Workqueue: events mptcp_worker RIP: 0010:inet_sock_destruct+0x6d0/0x8e0 net/ipv4/af_inet.c:153 Code: 21 02 00 00 41 8b 9c 24 28 02 00 00 e9 07 ff ff ff e8 34 4d 91 f9 89 ee 4c 89 e7 e8 4a 47 60 ff e9 a6 fc ff ff e8 20 4d 91 f9 <0f> 0b e9 84 fe ff ff e8 14 4d 91 f9 0f 0b e9 d4 fd ff ff e8 08 4d RSP: 0018:ffffc9001b35fa78 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 00000000002879d0 RCX: ffff8881326f3b00 RDX: 0000000000000000 RSI: ffff8881326f3b00 RDI: 0000000000000002 RBP: ffff888179662674 R08: ffffffff87e983a0 R09: 0000000000000000 R10: 0000000000000005 R11: 00000000000004ea R12: ffff888179662400 R13: ffff888179662428 R14: 0000000000000001 R15: ffff88817e38e258 FS: 0000000000000000(0000) GS:ffff8881f5f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020007bc0 CR3: 0000000179592000 CR4: 0000000000150ee0 Call Trace: <TASK> __sk_destruct+0x4f/0x8e0 net/core/sock.c:2067 sk_destruct+0xbd/0xe0 net/core/sock.c:2112 __sk_free+0xef/0x3d0 net/core/sock.c:2123 sk_free+0x78/0xa0 net/core/sock.c:2134 sock_put include/net/sock.h:1927 [inline] __mptcp_close_ssk+0x50f/0x780 net/mptcp/protocol.c:2351 __mptcp_destroy_sock+0x332/0x760 net/mptcp/protocol.c:2828 mptcp_worker+0x5d2/0xc90 net/mptcp/protocol.c:2586 process_one_work+0x9cc/0x1650 kernel/workqueue.c:2289 worker_thread+0x623/0x1070 kernel/workqueue.c:2436 kthread+0x2e9/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:302 </TASK> The root cause of the problem is that an mptcp-level (re)transmit can race with mptcp_close() and the packet scheduler checks the subflow state before acquiring the socket lock: we can try to (re)transmit on an already closed ssk. Fix the issue checking again the subflow socket status under the subflow socket lock protection. Additionally add the missing check for the fallback-to-tcp case. Fixes: d5f49190de ("mptcp: allow picking different xmit subflows") Reported-by: Dipanjan Das <mail.dipanjan.das@gmail.com> Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>		2022-08-05 08:51:28 +01:00
..
Kconfig	kunit: mptcp: adhere to KUNIT formatting standard	2021-04-16 17:10:40 -07:00
Makefile	Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next	2022-05-23 16:07:14 -07:00
bpf.c	bpf: Add bpf_skc_to_mptcp_sock_proto	2022-05-20 15:29:00 -07:00
crypto.c	kunit: mptcp: adhere to KUNIT formatting standard	2021-04-16 17:10:40 -07:00
crypto_test.c	mptcp: move crypto test to KUNIT	2020-06-26 16:21:39 -07:00
ctrl.c	mptcp: Add a per-namespace sysctl to set the default path manager type	2022-04-29 17:25:14 -07:00
diag.c	mptcp: allow dumping subflow context to userspace	2020-03-29 22:14:48 -07:00
mib.c	mptcp: add more offered MIBs counter	2022-05-05 19:00:16 -07:00
mib.h	mptcp: add more offered MIBs counter	2022-05-05 19:00:16 -07:00
mptcp_diag.c	net: inet: Retire port only listening_hash	2022-05-12 16:52:18 -07:00
options.c	tcp: Fix data-races around sysctl_tcp_workaround_signed_windows.	2022-07-22 12:06:17 +01:00
pm.c	mptcp: invoke MP_FAIL response when needed	2022-06-28 20:45:42 -07:00
pm_netlink.c	mptcp: more accurate MPC endpoint tracking	2022-07-12 18:37:20 -07:00
pm_userspace.c	mptcp: update MIB_RMSUBFLOW in cmd_sf_destroy	2022-07-06 12:50:26 +01:00
protocol.c	mptcp: do not queue data on closed subflows	2022-08-05 08:51:28 +01:00
protocol.h	mptcp: do not queue data on closed subflows	2022-08-05 08:51:28 +01:00
sockopt.c	mptcp: sockopt: add TCP_DEFER_ACCEPT support	2022-05-16 13:11:31 -07:00
subflow.c	mptcp: move subflow cleanup in mptcp_destroy_common()	2022-08-05 08:51:28 +01:00
syncookies.c	mptcp: don't return sockets in foreign netns	2021-09-24 10:51:36 +01:00
token.c	mptcp: full disconnect implementation	2022-01-07 11:27:06 +00:00
token_test.c	mptcp: don't return sockets in foreign netns	2021-09-24 10:51:36 +01:00