Hello, syzbot found the following issue on: HEAD commit: d012a719 Linux 5.9-rc2 git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=15aa650e900000 kernel config: https://syzkaller.appspot.com/x/.config?x=891ca5711a9f1650 dashboard link: https://syzkaller.appspot.com/bug?extid=c92c93d1f1aaaacdb9db compiler: clang version 10.0.0 (https://github.com/llvm/llvm-project/ c2443155a0fb245c8f17f2c1c72b6ea391e86e81) syz repro: https://syzkaller.appspot.com/x/repro.syz?x=12ecb939900000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=140a19a9900000 The issue was bisected to: commit a9ed4a6560b8562b7e2e2bed9527e88001f7b682 Author: Marc Zyngier <maz@xxxxxxxxxx> Date: Wed Aug 19 16:12:17 2020 +0000 epoll: Keep a reference on files added to the check list bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=16a50519900000 final oops: https://syzkaller.appspot.com/x/report.txt?x=15a50519900000 console output: https://syzkaller.appspot.com/x/log.txt?x=11a50519900000 IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+c92c93d1f1aaaacdb9db@xxxxxxxxxxxxxxxxxxxxxxxxx Fixes: a9ed4a6560b8 ("epoll: Keep a reference on files added to the check list") ------------[ cut here ]------------ kernel BUG at fs/inode.c:1668! invalid opcode: 0000 [#1] PREEMPT SMP KASAN CPU: 0 PID: 29571 Comm: syz-executor709 Not tainted 5.9.0-rc2-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:iput+0x6d8/0x6e0 fs/inode.c:1668 Code: ef ff e9 1a fc ff ff 44 89 e9 80 e1 07 80 c1 03 38 c1 0f 8c c8 fe ff ff 4c 89 ef e8 a2 51 ef ff e9 bb fe ff ff e8 68 77 af ff <0f> 0b 66 0f 1f 44 00 00 55 41 57 41 56 53 48 89 f5 48 89 fb 49 bf RSP: 0018:ffffc9000e25fda8 EFLAGS: 00010293 RAX: ffffffff81c580b8 RBX: ffff888085112600 RCX: ffff8880a6eea200 RDX: 0000000000000000 RSI: 0000000000000040 RDI: 0000000000000000 RBP: 0000000000000040 R08: ffffffff81c57a40 R09: ffffed10116fe44d R10: ffffed10116fe44d R11: 0000000000000000 R12: 1ffff11010a224ac R13: dffffc0000000000 R14: ffff888085112600 R15: ffff888085112560 FS: 0000000001665880(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020000000 CR3: 000000008f752000 CR4: 00000000001506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __sock_release net/socket.c:608 [inline] sock_close+0x1c3/0x260 net/socket.c:1277 __fput+0x34f/0x7b0 fs/file_table.c:281 task_work_run+0x137/0x1c0 kernel/task_work.c:141 tracehook_notify_resume include/linux/tracehook.h:188 [inline] exit_to_user_mode_loop kernel/entry/common.c:140 [inline] exit_to_user_mode_prepare+0xfa/0x1b0 kernel/entry/common.c:167 syscall_exit_to_user_mode+0x5e/0x1a0 kernel/entry/common.c:242 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x4058e1 Code: 75 14 b8 03 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 04 19 00 00 c3 48 83 ec 08 e8 6a fc ff ff 48 89 04 24 b8 03 00 00 00 0f 05 <48> 8b 3c 24 48 89 c2 e8 b3 fc ff ff 48 89 d0 48 83 c4 08 48 3d 01 RSP: 002b:00007ffc7ca575a0 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000006 RCX: 00000000004058e1 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000005 RBP: 0000000000000007 R08: 0000000120080522 R09: 0000000120080522 R10: 0000000120080522 R11: 0000000000000293 R12: 00000000006dbc5c R13: 0000000000000001 R14: 00000000006dbc50 R15: 0000000000000064 Modules linked in: ---[ end trace 35240c511479d576 ]--- RIP: 0010:iput+0x6d8/0x6e0 fs/inode.c:1668 Code: ef ff e9 1a fc ff ff 44 89 e9 80 e1 07 80 c1 03 38 c1 0f 8c c8 fe ff ff 4c 89 ef e8 a2 51 ef ff e9 bb fe ff ff e8 68 77 af ff <0f> 0b 66 0f 1f 44 00 00 55 41 57 41 56 53 48 89 f5 48 89 fb 49 bf RSP: 0018:ffffc9000e25fda8 EFLAGS: 00010293 RAX: ffffffff81c580b8 RBX: ffff888085112600 RCX: ffff8880a6eea200 RDX: 0000000000000000 RSI: 0000000000000040 RDI: 0000000000000000 RBP: 0000000000000040 R08: ffffffff81c57a40 R09: ffffed10116fe44d R10: ffffed10116fe44d R11: 0000000000000000 R12: 1ffff11010a224ac R13: dffffc0000000000 R14: ffff888085112600 R15: ffff888085112560 FS: 0000000001665880(0000) GS:ffff8880ae900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020000000 CR3: 000000008f752000 CR4: 00000000001506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 --- This report 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 issue. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot. For information about bisection process see: https://goo.gl/tpsmEJ#bisection syzbot can test patches for this issue, for details see: https://goo.gl/tpsmEJ#testing-patches
