On 01/02/2019 12:29 PM, Eric Dumazet wrote: > > > On 01/02/2019 02:41 AM, syzbot wrote: >> Hello, >> >> syzbot found the following crash on: >> >> HEAD commit: 28e8c4bc8eb4 Merge tag 'rtc-4.21' of git://git.kernel.org/.. >> git tree: upstream >> console output: https://syzkaller.appspot.com/x/log.txt?x=10c040d3400000 >> kernel config: https://syzkaller.appspot.com/x/.config?x=c2ab9708c613a224 >> dashboard link: https://syzkaller.appspot.com/bug?extid=5dd1f9327a9ee760048c >> compiler: gcc (GCC) 9.0.0 20181231 (experimental) >> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=15d17880c00000 >> >> IMPORTANT: if you fix the bug, please add the following tag to the commit: >> Reported-by: syzbot+5dd1f9327a9ee760048c@xxxxxxxxxxxxxxxxxxxxxxxxx >> >> IPv6: ADDRCONF(NETDEV_CHANGE): team0: link becomes ready >> IPv6: ADDRCONF(NETDEV_UP): vxcan1: link is not ready >> 8021q: adding VLAN 0 to HW filter on device batadv0 >> kasan: CONFIG_KASAN_INLINE enabled >> kasan: GPF could be caused by NULL-ptr deref or user memory access >> general protection fault: 0000 [#1] PREEMPT SMP KASAN >> CPU: 1 PID: 7982 Comm: syz-executor0 Not tainted 4.20.0+ #4 >> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 >> RIP: 0010:smc_diag_msg_common_fill net/smc/smc_diag.c:43 [inline] >> RIP: 0010:__smc_diag_dump.isra.0+0x32a/0x2ba0 net/smc/smc_diag.c:93 >> Code: 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 26 25 00 00 48 b8 00 00 00 00 00 fc ff df 4d 8b 7f 20 49 8d 7f 0e 48 89 fa 48 c1 ea 03 <0f> b6 14 02 48 89 f8 83 e0 07 83 c0 01 38 d0 7c 08 84 d2 0f 85 d2 >> RSP: 0018:ffff88808a29f120 EFLAGS: 00010203 >> RAX: dffffc0000000000 RBX: ffff88807f4d7240 RCX: 0000000000000000 >> RDX: 0000000000000001 RSI: ffffffff87b4e7c2 RDI: 000000000000000e >> RBP: ffff88808a29f3e8 R08: ffff88808d5721c0 R09: ffff888098960e90 >> R10: fffffbfff14a0020 R11: ffffffff8a500103 R12: ffff88808878d760 >> R13: ffff888098960e40 R14: ffff88807f4d76a0 R15: 0000000000000000 >> FS: 00007f6b83b40700(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000 >> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 >> CR2: 0000000000000000 CR3: 0000000095561000 CR4: 00000000001406e0 >> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 >> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 >> Call Trace: >> smc_diag_dump_proto.isra.0+0x2e7/0x3c0 net/smc/smc_diag.c:211 >> smc_diag_dump+0x27/0x80 net/smc/smc_diag.c:225 >> netlink_dump+0x5f2/0x1070 net/netlink/af_netlink.c:2244 >> __netlink_dump_start+0x5b4/0x7e0 net/netlink/af_netlink.c:2352 >> netlink_dump_start include/linux/netlink.h:225 [inline] >> smc_diag_handler_dump+0x2a7/0x350 net/smc/smc_diag.c:242 >> __sock_diag_cmd net/core/sock_diag.c:232 [inline] >> sock_diag_rcv_msg+0x322/0x410 net/core/sock_diag.c:263 >> netlink_rcv_skb+0x17d/0x410 net/netlink/af_netlink.c:2477 >> sock_diag_rcv+0x2b/0x40 net/core/sock_diag.c:274 >> netlink_unicast_kernel net/netlink/af_netlink.c:1310 [inline] >> netlink_unicast+0x574/0x770 net/netlink/af_netlink.c:1336 >> netlink_sendmsg+0xa05/0xf90 net/netlink/af_netlink.c:1917 >> sock_sendmsg_nosec net/socket.c:621 [inline] >> sock_sendmsg+0xdd/0x130 net/socket.c:631 >> ___sys_sendmsg+0x7ec/0x910 net/socket.c:2116 >> __sys_sendmsg+0x112/0x270 net/socket.c:2154 >> __do_sys_sendmsg net/socket.c:2163 [inline] >> __se_sys_sendmsg net/socket.c:2161 [inline] >> __x64_sys_sendmsg+0x78/0xb0 net/socket.c:2161 >> do_syscall_64+0x1a3/0x800 arch/x86/entry/common.c:290 >> entry_SYSCALL_64_after_hwframe+0x49/0xbe >> RIP: 0033:0x457ec9 >> Code: 6d b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 3b b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 >> RSP: 002b:00007f6b83b3fc78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e >> RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000457ec9 >> RDX: 0000000000000000 RSI: 0000000020000040 RDI: 0000000000000006 >> RBP: 000000000073bf00 R08: 0000000000000000 R09: 0000000000000000 >> R10: 0000000000000000 R11: 0000000000000246 R12: 00007f6b83b406d4 >> R13: 00000000004c5188 R14: 00000000004d8a10 R15: 00000000ffffffff >> Modules linked in: >> ---[ end trace db4e074cdaa51579 ]--- >> RIP: 0010:smc_diag_msg_common_fill net/smc/smc_diag.c:43 [inline] >> RIP: 0010:__smc_diag_dump.isra.0+0x32a/0x2ba0 net/smc/smc_diag.c:93 >> Code: 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 26 25 00 00 48 b8 00 00 00 00 00 fc ff df 4d 8b 7f 20 49 8d 7f 0e 48 89 fa 48 c1 ea 03 <0f> b6 14 02 48 89 f8 83 e0 07 83 c0 01 38 d0 7c 08 84 d2 0f 85 d2 >> RSP: 0018:ffff88808a29f120 EFLAGS: 00010203 >> RAX: dffffc0000000000 RBX: ffff88807f4d7240 RCX: 0000000000000000 >> RDX: 0000000000000001 RSI: ffffffff87b4e7c2 RDI: 000000000000000e >> RBP: ffff88808a29f3e8 R08: ffff88808d5721c0 R09: ffff888098960e90 >> R10: fffffbfff14a0020 R11: ffffffff8a500103 R12: ffff88808878d760 >> R13: ffff888098960e40 R14: ffff88807f4d76a0 R15: 0000000000000000 >> FS: 00007f6b83b40700(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000 >> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 >> CR2: 0000000000000000 CR3: 0000000095561000 CR4: 00000000001406e0 >> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 >> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 >> >> >> --- >> This bug is generated by a bot. It may contain errors. >> See https://goo.gl/tpsmEJ for more information about syzbot. >> syzbot engineers can be reached at syzkaller@xxxxxxxxxxxxxxxx. >> >> syzbot will keep track of this bug report. See: >> https://goo.gl/tpsmEJ#bug-status-tracking for how to communicate with syzbot. >> syzbot can test patches for this bug, for details see: >> https://goo.gl/tpsmEJ#testing-patches > > > Probable fix would be : > > diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c > index c4da4a78d369e359f237772090ff0890a1782c5b..afa1e24fb935281219016c339b15939312f2c89c 100644 > --- a/net/smc/af_smc.c > +++ b/net/smc/af_smc.c > @@ -165,12 +165,12 @@ static int smc_release(struct socket *sock) > > /* detach socket */ > sock_orphan(sk); > - sock->sk = NULL; > if (!smc->use_fallback && sk->sk_state == SMC_CLOSED) > smc_conn_free(&smc->conn); > release_sock(sk); > > sk->sk_prot->unhash(sk); > + sock->sk = NULL; > sock_put(sk); /* final sock_put */ > out: > return rc; > Cong Wang now comes up with a different patch proposal, which makes sense in my eyes.
