This is a note to let you know that I've just added the patch titled dccp: do not send reset to already closed sockets to the 4.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: dccp-do-not-send-reset-to-already-closed-sockets.patch and it can be found in the queue-4.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From foo@baz Fri Nov 18 11:09:43 CET 2016 From: Eric Dumazet <edumazet@xxxxxxxxxx> Date: Wed, 2 Nov 2016 18:04:24 -0700 Subject: dccp: do not send reset to already closed sockets From: Eric Dumazet <edumazet@xxxxxxxxxx> [ Upstream commit 346da62cc186c4b4b1ac59f87f4482b47a047388 ] Andrey reported following warning while fuzzing with syzkaller WARNING: CPU: 1 PID: 21072 at net/dccp/proto.c:83 dccp_set_state+0x229/0x290 Kernel panic - not syncing: panic_on_warn set ... CPU: 1 PID: 21072 Comm: syz-executor Not tainted 4.9.0-rc1+ #293 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 ffff88003d4c7738 ffffffff81b474f4 0000000000000003 dffffc0000000000 ffffffff844f8b00 ffff88003d4c7804 ffff88003d4c7800 ffffffff8140c06a 0000000041b58ab3 ffffffff8479ab7d ffffffff8140beae ffffffff8140cd00 Call Trace: [< inline >] __dump_stack lib/dump_stack.c:15 [<ffffffff81b474f4>] dump_stack+0xb3/0x10f lib/dump_stack.c:51 [<ffffffff8140c06a>] panic+0x1bc/0x39d kernel/panic.c:179 [<ffffffff8111125c>] __warn+0x1cc/0x1f0 kernel/panic.c:542 [<ffffffff8111144c>] warn_slowpath_null+0x2c/0x40 kernel/panic.c:585 [<ffffffff8389e5d9>] dccp_set_state+0x229/0x290 net/dccp/proto.c:83 [<ffffffff838a0aa2>] dccp_close+0x612/0xc10 net/dccp/proto.c:1016 [<ffffffff8316bf1f>] inet_release+0xef/0x1c0 net/ipv4/af_inet.c:415 [<ffffffff82b6e89e>] sock_release+0x8e/0x1d0 net/socket.c:570 [<ffffffff82b6e9f6>] sock_close+0x16/0x20 net/socket.c:1017 [<ffffffff815256ad>] __fput+0x29d/0x720 fs/file_table.c:208 [<ffffffff81525bb5>] ____fput+0x15/0x20 fs/file_table.c:244 [<ffffffff811727d8>] task_work_run+0xf8/0x170 kernel/task_work.c:116 [< inline >] exit_task_work include/linux/task_work.h:21 [<ffffffff8111bc53>] do_exit+0x883/0x2ac0 kernel/exit.c:828 [<ffffffff811221fe>] do_group_exit+0x10e/0x340 kernel/exit.c:931 [<ffffffff81143c94>] get_signal+0x634/0x15a0 kernel/signal.c:2307 [<ffffffff81054aad>] do_signal+0x8d/0x1a30 arch/x86/kernel/signal.c:807 [<ffffffff81003a05>] exit_to_usermode_loop+0xe5/0x130 arch/x86/entry/common.c:156 [< inline >] prepare_exit_to_usermode arch/x86/entry/common.c:190 [<ffffffff81006298>] syscall_return_slowpath+0x1a8/0x1e0 arch/x86/entry/common.c:259 [<ffffffff83fc1a62>] entry_SYSCALL_64_fastpath+0xc0/0xc2 Dumping ftrace buffer: (ftrace buffer empty) Kernel Offset: disabled Fix this the same way we did for TCP in commit 565b7b2d2e63 ("tcp: do not send reset to already closed sockets") Signed-off-by: Eric Dumazet <edumazet@xxxxxxxxxx> Reported-by: Andrey Konovalov <andreyknvl@xxxxxxxxxx> Tested-by: Andrey Konovalov <andreyknvl@xxxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- net/dccp/proto.c | 4 ++++ 1 file changed, 4 insertions(+) --- a/net/dccp/proto.c +++ b/net/dccp/proto.c @@ -1009,6 +1009,10 @@ void dccp_close(struct sock *sk, long ti __kfree_skb(skb); } + /* If socket has been already reset kill it. */ + if (sk->sk_state == DCCP_CLOSED) + goto adjudge_to_death; + if (data_was_unread) { /* Unread data was tossed, send an appropriate Reset Code */ DCCP_WARN("ABORT with %u bytes unread\n", data_was_unread); Patches currently in stable-queue which might be from edumazet@xxxxxxxxxx are queue-4.4/net-__skb_flow_dissect-must-cap-its-return-value.patch queue-4.4/tcp-take-care-of-truncations-done-by-sk_filter.patch queue-4.4/net-clear-sk_err_soft-in-sk_clone_lock.patch queue-4.4/net-mangle-zero-checksum-in-skb_checksum_help.patch queue-4.4/ipv6-dccp-fix-out-of-bound-access-in-dccp_v6_err.patch queue-4.4/ipv6-dccp-add-missing-bind_conflict-to-dccp_ipv6_mapped.patch queue-4.4/tcp-fix-potential-memory-corruption.patch queue-4.4/dccp-do-not-send-reset-to-already-closed-sockets.patch queue-4.4/dccp-fix-out-of-bound-access-in-dccp_v4_err.patch queue-4.4/sock-fix-sendmmsg-for-partial-sendmsg.patch -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html