syzbot has found a reproducer for the following issue on: HEAD commit: 3dd0130f Merge branch 'akpm' (patches from Andrew) git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=1107d078500000 kernel config: https://syzkaller.appspot.com/x/.config?x=c06bcf3cc963d91c dashboard link: https://syzkaller.appspot.com/bug?extid=1541a3226994c0781b29 compiler: gcc (GCC) 10.1.0-syz 20200507 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=134aa19f900000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=149f6fbf900000 IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+1541a3226994c0781b29@xxxxxxxxxxxxxxxxxxxxxxxxx REISERFS panic (device loop0): journal-2332 do_journal_end: Trying to log block 8211, which is a log block ------------[ cut here ]------------ kernel BUG at fs/reiserfs/prints.c:390! invalid opcode: 0000 [#1] PREEMPT SMP KASAN CPU: 1 PID: 6887 Comm: syz-executor832 Not tainted 5.9.0-rc8-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:__reiserfs_panic.cold+0x37/0x8a fs/reiserfs/prints.c:390 Code: 9c 88 74 6d e8 cf 7c 7a ff 4c 89 e9 4c 89 f2 4c 89 e6 49 c7 c0 60 f2 4f 8d 48 c7 c7 20 b7 9c 88 e8 b2 85 63 ff e8 ae 7c 7a ff <0f> 0b e8 a7 7c 7a ff 4d 85 e4 49 c7 c6 60 b5 9c 88 75 0a 49 c7 c6 RSP: 0018:ffffc90000f07b00 EFLAGS: 00010293 RAX: 0000000000000000 RBX: ffff88809dd2c000 RCX: 0000000000000000 RDX: ffff8880a6a7e080 RSI: ffffffff81fbc262 RDI: fffff520001e0f52 RBP: ffffc90000f07bd0 R08: 000000000000006a R09: ffff8880ae5318e7 R10: 0000000000000000 R11: 0000000000000000 R12: ffffffff889d1d60 R13: ffffffff889d2560 R14: ffffffff889cb560 R15: 0000000000002016 FS: 0000000001815880(0000) GS:ffff8880ae500000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000000181e8b8 CR3: 00000000a26de000 CR4: 00000000001506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: do_journal_end+0x3d85/0x4950 fs/reiserfs/journal.c:4135 reiserfs_sync_fs+0xf8/0x120 fs/reiserfs/super.c:78 __sync_filesystem fs/sync.c:39 [inline] sync_filesystem fs/sync.c:64 [inline] sync_filesystem+0x105/0x260 fs/sync.c:48 generic_shutdown_super+0x70/0x370 fs/super.c:448 kill_block_super+0x97/0xf0 fs/super.c:1444 deactivate_locked_super+0x94/0x160 fs/super.c:335 deactivate_super+0xad/0xd0 fs/super.c:366 cleanup_mnt+0x3a3/0x530 fs/namespace.c:1118 task_work_run+0xdd/0x190 kernel/task_work.c:141 tracehook_notify_resume include/linux/tracehook.h:188 [inline] exit_to_user_mode_loop kernel/entry/common.c:165 [inline] exit_to_user_mode_prepare+0x1e1/0x200 kernel/entry/common.c:192 syscall_exit_to_user_mode+0x7e/0x2e0 kernel/entry/common.c:267 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x448177 Code: 00 00 00 b8 08 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 8d a2 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 b8 a6 00 00 00 0f 05 <48> 3d 01 f0 ff ff 0f 83 6d a2 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fff2be25a58 EFLAGS: 00000206 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 00007fff2be26bd0 RCX: 0000000000448177 RDX: 0000000000400cf7 RSI: 0000000000000002 RDI: 00007fff2be25b00 RBP: 00000000000211c2 R08: 0000000000000000 R09: 0000000000000009 R10: 0000000000000005 R11: 0000000000000206 R12: 00007fff2be26b70 R13: 0000000001816880 R14: 0000000000000000 R15: 0000000000000000 Modules linked in: ---[ end trace c00fc6b0fe3e7e74 ]--- RIP: 0010:__reiserfs_panic.cold+0x37/0x8a fs/reiserfs/prints.c:390 Code: 9c 88 74 6d e8 cf 7c 7a ff 4c 89 e9 4c 89 f2 4c 89 e6 49 c7 c0 60 f2 4f 8d 48 c7 c7 20 b7 9c 88 e8 b2 85 63 ff e8 ae 7c 7a ff <0f> 0b e8 a7 7c 7a ff 4d 85 e4 49 c7 c6 60 b5 9c 88 75 0a 49 c7 c6 RSP: 0018:ffffc90000f07b00 EFLAGS: 00010293 RAX: 0000000000000000 RBX: ffff88809dd2c000 RCX: 0000000000000000 RDX: ffff8880a6a7e080 RSI: ffffffff81fbc262 RDI: fffff520001e0f52 RBP: ffffc90000f07bd0 R08: 000000000000006a R09: ffff8880ae5318e7 R10: 0000000000000000 R11: 0000000000000000 R12: ffffffff889d1d60 R13: ffffffff889d2560 R14: ffffffff889cb560 R15: 0000000000002016 FS: 0000000001815880(0000) GS:ffff8880ae500000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000000181e8b8 CR3: 00000000a26de000 CR4: 00000000001506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400