From a5dcb73b96a9d21431048bdaac02d9e96f386da3 Mon Sep 17 00:00:00 2001 From: Davide Caratti Date: Wed, 28 Feb 2018 12:44:09 +0100 Subject: net/smc: fix NULL pointer dereference on sock_create_kern() error path when sock_create_kern(..., a) returns an error, 'a' might not be a valid pointer, so it shouldn't be dereferenced to read a->sk->sk_sndbuf and and a->sk->sk_rcvbuf; not doing that caused the following crash: general protection fault: 0000 [#1] SMP KASAN Dumping ftrace buffer: (ftrace buffer empty) Modules linked in: CPU: 0 PID: 4254 Comm: syzkaller919713 Not tainted 4.16.0-rc1+ #18 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:smc_create+0x14e/0x300 net/smc/af_smc.c:1410 RSP: 0018:ffff8801b06afbc8 EFLAGS: 00010202 RAX: dffffc0000000000 RBX: ffff8801b63457c0 RCX: ffffffff85a3e746 RDX: 0000000000000004 RSI: 00000000ffffffff RDI: 0000000000000020 RBP: ffff8801b06afbf0 R08: 00000000000007c0 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: ffff8801b6345c08 R14: 00000000ffffffe9 R15: ffffffff8695ced0 FS: 0000000001afb880(0000) GS:ffff8801db200000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020000040 CR3: 00000001b0721004 CR4: 00000000001606f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __sock_create+0x4d4/0x850 net/socket.c:1285 sock_create net/socket.c:1325 [inline] SYSC_socketpair net/socket.c:1409 [inline] SyS_socketpair+0x1c0/0x6f0 net/socket.c:1366 do_syscall_64+0x282/0x940 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x26/0x9b RIP: 0033:0x4404b9 RSP: 002b:00007fff44ab6908 EFLAGS: 00000246 ORIG_RAX: 0000000000000035 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00000000004404b9 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 000000000000002b RBP: 00007fff44ab6910 R08: 0000000000000002 R09: 00007fff44003031 R10: 0000000020000040 R11: 0000000000000246 R12: ffffffffffffffff R13: 0000000000000006 R14: 0000000000000000 R15: 0000000000000000 Code: 48 c1 ea 03 80 3c 02 00 0f 85 b3 01 00 00 4c 8b a3 48 04 00 00 48 b8 00 00 00 00 00 fc ff df 49 8d 7c 24 20 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 82 01 00 00 4d 8b 7c 24 20 48 b8 00 00 00 00 RIP: smc_create+0x14e/0x300 net/smc/af_smc.c:1410 RSP: ffff8801b06afbc8 Fixes: cd6851f30386 smc: remote memory buffers (RMBs) Reported-and-tested-by: syzbot+aa0227369be2dcc26ebe@syzkaller.appspotmail.com Signed-off-by: Davide Caratti Signed-off-by: Ursula Braun Signed-off-by: David S. Miller --- net/smc/af_smc.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'net/smc/af_smc.c') diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c index da1a5cdefd13..8cc97834d4f6 100644 --- a/net/smc/af_smc.c +++ b/net/smc/af_smc.c @@ -1406,8 +1406,10 @@ static int smc_create(struct net *net, struct socket *sock, int protocol, smc->use_fallback = false; /* assume rdma capability first */ rc = sock_create_kern(net, PF_INET, SOCK_STREAM, IPPROTO_TCP, &smc->clcsock); - if (rc) + if (rc) { sk_common_release(sk); + goto out; + } smc->sk.sk_sndbuf = max(smc->clcsock->sk->sk_sndbuf, SMC_BUF_MIN_SIZE); smc->sk.sk_rcvbuf = max(smc->clcsock->sk->sk_rcvbuf, SMC_BUF_MIN_SIZE); -- cgit v1.2.3-55-g7522 From 3d502067599f0db12e74e6646aee8728efe3e5be Mon Sep 17 00:00:00 2001 From: Ursula Braun Date: Tue, 13 Mar 2018 10:41:54 +0100 Subject: net/smc: simplify wait when closing listen socket Closing of a listen socket wakes up kernel_accept() of smc_tcp_listen_worker(), and then has to wait till smc_tcp_listen_worker() gives up the internal clcsock. The wait logic introduced with commit 127f49705823 ("net/smc: release clcsock from tcp_listen_worker") might wait longer than necessary. This patch implements the idea to implement the wait just with flush_work(), and gets rid of the extra smc_close_wait_listen_clcsock() function. Fixes: 127f49705823 ("net/smc: release clcsock from tcp_listen_worker") Reported-by: Hans Wippel Signed-off-by: Ursula Braun Signed-off-by: David S. Miller --- net/smc/af_smc.c | 4 ---- net/smc/smc_close.c | 25 +++---------------------- 2 files changed, 3 insertions(+), 26 deletions(-) (limited to 'net/smc/af_smc.c') diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c index 8cc97834d4f6..1e0d780855c3 100644 --- a/net/smc/af_smc.c +++ b/net/smc/af_smc.c @@ -978,10 +978,6 @@ out: lsmc->clcsock = NULL; } release_sock(lsk); - /* no more listening, wake up smc_close_wait_listen_clcsock and - * accept - */ - lsk->sk_state_change(lsk); sock_put(&lsmc->sk); /* sock_hold in smc_listen */ } diff --git a/net/smc/smc_close.c b/net/smc/smc_close.c index e339c0186dcf..fa41d9881741 100644 --- a/net/smc/smc_close.c +++ b/net/smc/smc_close.c @@ -30,27 +30,6 @@ static void smc_close_cleanup_listen(struct sock *parent) smc_close_non_accepted(sk); } -static void smc_close_wait_listen_clcsock(struct smc_sock *smc) -{ - DEFINE_WAIT_FUNC(wait, woken_wake_function); - struct sock *sk = &smc->sk; - signed long timeout; - - timeout = SMC_CLOSE_WAIT_LISTEN_CLCSOCK_TIME; - add_wait_queue(sk_sleep(sk), &wait); - do { - release_sock(sk); - if (smc->clcsock) - timeout = wait_woken(&wait, TASK_UNINTERRUPTIBLE, - timeout); - sched_annotate_sleep(); - lock_sock(sk); - if (!smc->clcsock) - break; - } while (timeout); - remove_wait_queue(sk_sleep(sk), &wait); -} - /* wait for sndbuf data being transmitted */ static void smc_close_stream_wait(struct smc_sock *smc, long timeout) { @@ -204,9 +183,11 @@ again: rc = kernel_sock_shutdown(smc->clcsock, SHUT_RDWR); /* wake up kernel_accept of smc_tcp_listen_worker */ smc->clcsock->sk->sk_data_ready(smc->clcsock->sk); - smc_close_wait_listen_clcsock(smc); } smc_close_cleanup_listen(sk); + release_sock(sk); + flush_work(&smc->tcp_listen_work); + lock_sock(sk); break; case SMC_ACTIVE: smc_close_stream_wait(smc, timeout); -- cgit v1.2.3-55-g7522