From c19ae2f66bf98729e9be4032a6a03874c06673a7 Mon Sep 17 00:00:00 2001 From: Xin Long Date: Sat, 10 Jun 2017 14:56:56 +0800 Subject: sctp: fix recursive locking warning in sctp_do_peeloff [ Upstream commit 6dfe4b97e08ec3d1a593fdaca099f0ef0a3a19e6 ] Dmitry got the following recursive locking report while running syzkaller fuzzer, the Call Trace: __dump_stack lib/dump_stack.c:16 [inline] dump_stack+0x2ee/0x3ef lib/dump_stack.c:52 print_deadlock_bug kernel/locking/lockdep.c:1729 [inline] check_deadlock kernel/locking/lockdep.c:1773 [inline] validate_chain kernel/locking/lockdep.c:2251 [inline] __lock_acquire+0xef2/0x3430 kernel/locking/lockdep.c:3340 lock_acquire+0x2a1/0x630 kernel/locking/lockdep.c:3755 lock_sock_nested+0xcb/0x120 net/core/sock.c:2536 lock_sock include/net/sock.h:1460 [inline] sctp_close+0xcd/0x9d0 net/sctp/socket.c:1497 inet_release+0xed/0x1c0 net/ipv4/af_inet.c:425 inet6_release+0x50/0x70 net/ipv6/af_inet6.c:432 sock_release+0x8d/0x1e0 net/socket.c:597 __sock_create+0x38b/0x870 net/socket.c:1226 sock_create+0x7f/0xa0 net/socket.c:1237 sctp_do_peeloff+0x1a2/0x440 net/sctp/socket.c:4879 sctp_getsockopt_peeloff net/sctp/socket.c:4914 [inline] sctp_getsockopt+0x111a/0x67e0 net/sctp/socket.c:6628 sock_common_getsockopt+0x95/0xd0 net/core/sock.c:2690 SYSC_getsockopt net/socket.c:1817 [inline] SyS_getsockopt+0x240/0x380 net/socket.c:1799 entry_SYSCALL_64_fastpath+0x1f/0xc2 This warning is caused by the lock held by sctp_getsockopt() is on one socket, while the other lock that sctp_close() is getting later is on the newly created (which failed) socket during peeloff operation. This patch is to avoid this warning by use lock_sock with subclass SINGLE_DEPTH_NESTING as Wang Cong and Marcelo's suggestion. Reported-by: Dmitry Vyukov Suggested-by: Marcelo Ricardo Leitner Suggested-by: Cong Wang Signed-off-by: Xin Long Acked-by: Marcelo Ricardo Leitner Signed-off-by: David S. Miller Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- net/sctp/socket.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'net/sctp/socket.c') diff --git a/net/sctp/socket.c b/net/sctp/socket.c index df6a4b2d0728..8efdf7fc1044 100644 --- a/net/sctp/socket.c +++ b/net/sctp/socket.c @@ -1518,7 +1518,7 @@ static void sctp_close(struct sock *sk, long timeout) pr_debug("%s: sk:%p, timeout:%ld\n", __func__, sk, timeout); - lock_sock(sk); + lock_sock_nested(sk, SINGLE_DEPTH_NESTING); sk->sk_shutdown = SHUTDOWN_MASK; sk->sk_state = SCTP_SS_CLOSING; @@ -1569,7 +1569,7 @@ static void sctp_close(struct sock *sk, long timeout) * held and that should be grabbed before socket lock. */ spin_lock_bh(&net->sctp.addr_wq_lock); - bh_lock_sock(sk); + bh_lock_sock_nested(sk); /* Hold the sock, since sk_common_release() will put sock_put() * and we have just a little more cleanup. -- cgit v1.2.3 From fb2f3af62b92ae3ce46b92ede2a0fbf50afdfc6c Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Sun, 8 Apr 2018 07:52:08 -0700 Subject: sctp: sctp_sockaddr_af must check minimal addr length for AF_INET6 [ Upstream commit 81e98370293afcb58340ce8bd71af7b97f925c26 ] Check must happen before call to ipv6_addr_v4mapped() syzbot report was : BUG: KMSAN: uninit-value in sctp_sockaddr_af net/sctp/socket.c:359 [inline] BUG: KMSAN: uninit-value in sctp_do_bind+0x60f/0xdc0 net/sctp/socket.c:384 CPU: 0 PID: 3576 Comm: syzkaller968804 Not tainted 4.16.0+ #82 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x185/0x1d0 lib/dump_stack.c:53 kmsan_report+0x142/0x240 mm/kmsan/kmsan.c:1067 __msan_warning_32+0x6c/0xb0 mm/kmsan/kmsan_instr.c:676 sctp_sockaddr_af net/sctp/socket.c:359 [inline] sctp_do_bind+0x60f/0xdc0 net/sctp/socket.c:384 sctp_bind+0x149/0x190 net/sctp/socket.c:332 inet6_bind+0x1fd/0x1820 net/ipv6/af_inet6.c:293 SYSC_bind+0x3f2/0x4b0 net/socket.c:1474 SyS_bind+0x54/0x80 net/socket.c:1460 do_syscall_64+0x309/0x430 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x3d/0xa2 RIP: 0033:0x43fd49 RSP: 002b:00007ffe99df3d28 EFLAGS: 00000213 ORIG_RAX: 0000000000000031 RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 000000000043fd49 RDX: 0000000000000010 RSI: 0000000020000000 RDI: 0000000000000003 RBP: 00000000006ca018 R08: 00000000004002c8 R09: 00000000004002c8 R10: 00000000004002c8 R11: 0000000000000213 R12: 0000000000401670 R13: 0000000000401700 R14: 0000000000000000 R15: 0000000000000000 Local variable description: ----address@SYSC_bind Variable was created at: SYSC_bind+0x6f/0x4b0 net/socket.c:1461 SyS_bind+0x54/0x80 net/socket.c:1460 Signed-off-by: Eric Dumazet Cc: Vlad Yasevich Cc: Neil Horman Reported-by: syzbot Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/sctp/socket.c | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-) (limited to 'net/sctp/socket.c') diff --git a/net/sctp/socket.c b/net/sctp/socket.c index 8efdf7fc1044..13c7f42b7040 100644 --- a/net/sctp/socket.c +++ b/net/sctp/socket.c @@ -335,11 +335,14 @@ static struct sctp_af *sctp_sockaddr_af(struct sctp_sock *opt, if (!opt->pf->af_supported(addr->sa.sa_family, opt)) return NULL; - /* V4 mapped address are really of AF_INET family */ - if (addr->sa.sa_family == AF_INET6 && - ipv6_addr_v4mapped(&addr->v6.sin6_addr) && - !opt->pf->af_supported(AF_INET, opt)) - return NULL; + if (addr->sa.sa_family == AF_INET6) { + if (len < SIN6_LEN_RFC2133) + return NULL; + /* V4 mapped address are really of AF_INET family */ + if (ipv6_addr_v4mapped(&addr->v6.sin6_addr) && + !opt->pf->af_supported(AF_INET, opt)) + return NULL; + } /* If we get this far, af is valid. */ af = sctp_get_af_specific(addr->sa.sa_family); -- cgit v1.2.3