On Sat, Mar 31, 2018 at 04:01:02PM -0700, syzbot wrote: > Hello, > > syzbot hit the following crash on bpf-next commit > 7828f20e3779e4e85e55371e0e43f5006a15fb41 (Sat Mar 31 00:17:57 2018 +0000) > Merge branch 'bpf-cgroup-bind-connect' > syzbot dashboard link: > https://syzkaller.appspot.com/bug?extid=f3bd89a5ab3266b10540 > > So far this crash happened 22 times on bpf-next, upstream. > C reproducer: https://syzkaller.appspot.com/x/repro.c?id=6290970458980352 > syzkaller reproducer: > https://syzkaller.appspot.com/x/repro.syz?id=6577156880596992 > Raw console output: > https://syzkaller.appspot.com/x/log.txt?id=5107570603720704 > Kernel config: > https://syzkaller.appspot.com/x/.config?id=5909223872832634926 > compiler: gcc (GCC) 7.1.1 20170620 > > IMPORTANT: if you fix the bug, please add the following tag to the commit: > Reported-by: syzbot+f3bd89a5ab3266b10540@xxxxxxxxxxxxxxxxxxxxxxxxx > It will help syzbot understand when the bug is fixed. See footer for > details. > If you forward the report, please keep this part and the footer. > > RBP: 00007ffd1bbb3ae0 R08: 0000000020000200 R09: 0000000300000000 > R10: 0000000000000000 R11: 0000000000000246 R12: ffffffffffffffff > R13: 0000000000000003 R14: 0000000000001380 R15: 00007ffd1bbb3378 > list_del corruption. prev->next should be 00000000a8104008, but was > 00000000081c6144 > ------------[ cut here ]------------ > kernel BUG at lib/list_debug.c:53! > invalid opcode: 0000 [#1] SMP KASAN > Dumping ftrace buffer: > (ftrace buffer empty) > Modules linked in: > CPU: 0 PID: 4448 Comm: syzkaller853443 Not tainted 4.16.0-rc6+ #43 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS > Google 01/01/2011 > RIP: 0010:__list_del_entry_valid+0xef/0x150 lib/list_debug.c:51 > RSP: 0018:ffff8801b8f977a0 EFLAGS: 00010282 > RAX: 0000000000000054 RBX: ffff8801b0c1cf60 RCX: 0000000000000000 > RDX: 0000000000000054 RSI: 1ffff100371f2ea9 RDI: ffffed00371f2ee8 > RBP: ffff8801b8f977b8 R08: 1ffff100371f2e40 R09: 0000000000000000 > R10: ffff8801b8f97778 R11: 0000000000000000 R12: ffff8801b0c1cde0 > R13: 1ffff100371f2efd R14: ffff8801b0c1cc70 R15: dffffc0000000000 > FS: 00000000023a5880(0000) GS:ffff8801db000000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 00000000004b6fbc CR3: 00000001c85a6004 CR4: 00000000001606f0 > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > Call Trace: > __list_del_entry include/linux/list.h:117 [inline] > dentry_unlist fs/dcache.c:518 [inline] > __dentry_kill+0x260/0x700 fs/dcache.c:571 > dentry_kill fs/dcache.c:616 [inline] > dput.part.20+0x5a0/0x830 fs/dcache.c:831 > dput+0x1f/0x30 fs/dcache.c:795 > rpc_gssd_dummy_depopulate net/sunrpc/rpc_pipe.c:1381 [inline] > rpc_fill_super+0x628/0xae0 net/sunrpc/rpc_pipe.c:1426 > mount_ns+0xc4/0x190 fs/super.c:1036 > rpc_mount+0x9e/0xd0 net/sunrpc/rpc_pipe.c:1451 > mount_fs+0x66/0x2d0 fs/super.c:1222 > vfs_kern_mount.part.26+0xc6/0x4a0 fs/namespace.c:1037 > vfs_kern_mount fs/namespace.c:2509 [inline] > do_new_mount fs/namespace.c:2512 [inline] > do_mount+0xea4/0x2bb0 fs/namespace.c:2842 > SYSC_mount fs/namespace.c:3058 [inline] > SyS_mount+0xab/0x120 fs/namespace.c:3035 > do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287 > entry_SYSCALL_64_after_hwframe+0x42/0xb7 > RIP: 0033:0x442759 > RSP: 002b:00007ffd1bbb3238 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 > RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000442759 > RDX: 00000000200002c0 RSI: 0000000020000140 RDI: 0000000020000300 > RBP: 00007ffd1bbb3ae0 R08: 0000000020000200 R09: 0000000300000000 > R10: 0000000000000000 R11: 0000000000000246 R12: ffffffffffffffff > R13: 0000000000000003 R14: 0000000000001380 R15: 00007ffd1bbb3378 > Code: 4c 89 e2 48 c7 c7 c0 bf 75 87 e8 35 c1 46 fe 0f 0b 48 c7 c7 20 c0 75 > 87 e8 27 c1 46 fe 0f 0b 48 c7 c7 80 c0 75 87 e8 19 c1 46 fe <0f> 0b 48 c7 c7 > e0 c0 75 87 e8 0b c1 46 fe 0f 0b 48 89 df 48 89 > RIP: __list_del_entry_valid+0xef/0x150 lib/list_debug.c:51 RSP: > ffff8801b8f977a0 > ---[ end trace e1b9954cded9aca7 ]--- > > > --- > This bug is generated by a dumb bot. It may contain errors. > See https://goo.gl/tpsmEJ for details. > Direct all questions to syzkaller@xxxxxxxxxxxxxxxx. > > syzbot will keep track of this bug report. > If you forgot to add the Reported-by tag, once the fix for this bug is > merged > into any tree, please reply to this email with: > #syz fix: exact-commit-title #syz fix: rpc_pipefs: fix double-dput() Al, it would be helpful if for syzbot-reported bugs you used the Reported-by line suggested in the bug report. That allows the bug to be automatically closed, and it's also useful for people who are looking for syzbot bug fixes. Thanks! Eric
