bisecting fixing commit since 13d2ce42de8cb98ff952f8de6307f896203854c2 building syzkaller on bca53db974f570410921f59b8c2c59a3d263cb44 testing commit 13d2ce42de8cb98ff952f8de6307f896203854c2 with gcc (GCC) 8.1.0 kernel signature: 175618543a922d67f9280e9f740033c73f8bc308ae29c57ff6f05be24840aec9 run #0: crashed: BUG: Dentry ADDR{i=0,n=/} still in use (-128) [unmount of erofs loop4] run #1: crashed: kernel BUG at fs/inode.c:LINE! run #2: crashed: kernel BUG at fs/inode.c:LINE! run #3: crashed: BUG: Dentry ADDR{i=0,n=/} still in use (-128) [unmount of erofs loop5] run #4: crashed: BUG: Dentry ADDR{i=0,n=/} still in use (-128) [unmount of erofs loop1] run #5: crashed: BUG: Dentry ADDR{i=0,n=/} still in use (-128) [unmount of erofs loop0] run #6: crashed: kernel BUG at fs/inode.c:LINE! run #7: crashed: BUG: Dentry ADDR{i=0,n=/} still in use (-128) [unmount of erofs loop0] run #8: crashed: kernel BUG at fs/inode.c:LINE! run #9: crashed: BUG: Dentry ADDR{i=0,n=/} still in use (-128) [unmount of erofs loop4] testing current HEAD 610bdbf6a174c9a91e34e276a9594114b44bef74 testing commit 610bdbf6a174c9a91e34e276a9594114b44bef74 with gcc (GCC) 8.1.0 kernel signature: 40f48d513da0445c6759933de71bc7b603a958a3d1ef60b768ad671cf1b39b30 run #0: crashed: kernel BUG at fs/inode.c:LINE! run #1: crashed: kernel BUG at fs/inode.c:LINE! run #2: crashed: kernel BUG at fs/inode.c:LINE! run #3: crashed: kernel BUG at fs/inode.c:LINE! run #4: crashed: BUG: Dentry ADDR{i=0,n=/} still in use (-128) [unmount of erofs loop2] run #5: crashed: kernel BUG at fs/inode.c:LINE! run #6: crashed: BUG: Dentry ADDR{i=0,n=/} still in use (-128) [unmount of erofs loop2] run #7: crashed: kernel BUG at fs/inode.c:LINE! run #8: crashed: kernel BUG at fs/inode.c:LINE! run #9: crashed: kernel BUG at fs/inode.c:LINE! revisions tested: 2, total time: 23m12.251937968s (build: 16m38.932224002s, test: 5m58.432161411s) the crash still happens on HEAD commit msg: Linux 4.19.166 crash: kernel BUG at fs/inode.c:LINE! R10: 0000000000000000 R11: 0000000000000246 R12: 0000000020000000 R13: 0000000020000100 R14: 0000000020000200 R15: 0000000020010a00 CPU: 1 PID: 10201 Comm: syz-executor.2 Not tainted 4.19.166-syzkaller #0 ------------[ cut here ]------------ Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 kernel BUG at fs/inode.c:1571! Call Trace: invalid opcode: 0000 [#1] PREEMPT SMP KASAN __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x17c/0x22a lib/dump_stack.c:118 CPU: 0 PID: 10182 Comm: syz-executor.0 Not tainted 4.19.166-syzkaller #0 fail_dump lib/fault-inject.c:51 [inline] should_fail.cold.2+0x5/0xb lib/fault-inject.c:149 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:iput+0x536/0x6b0 fs/inode.c:1571 __should_failslab+0xba/0xf0 mm/failslab.c:32 Code: 48 b8 00 00 00 00 00 fc ff df 48 8b 55 c8 48 c1 ea 03 80 3c 02 00 0f 84 ac fd ff ff 48 8b 7d c8 e8 6f 95 f0 ff e9 9e fd ff ff <0f> 0b 48 89 df e8 60 f9 ff ff 48 8b 7d d0 e8 b7 c4 04 06 e9 2a fe should_failslab+0x9/0x14 mm/slab_common.c:1588 RSP: 0018:ffff88807e8f7a18 EFLAGS: 00010202 slab_pre_alloc_hook mm/slab.h:424 [inline] slab_alloc mm/slab.c:3383 [inline] kmem_cache_alloc_trace+0x2a7/0x3a0 mm/slab.c:3623 RAX: dffffc0000000000 RBX: ffff88808dbf3268 RCX: 1ffff1101516fdad kmalloc include/linux/slab.h:515 [inline] kzalloc include/linux/slab.h:709 [inline] erofs_read_super drivers/staging/erofs/super.c:349 [inline] erofs_fill_super+0x15c/0x1168 drivers/staging/erofs/super.c:499 RDX: 1ffff11011b7e667 RSI: ffff8880a8b7ed48 RDI: ffff88808dbf3268 RBP: ffff88807e8f7a60 R08: ffff8880a8b7ed68 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffff88808dbf3268 R13: ffff8880910a6500 R14: 0000000000000000 R15: ffff8880910a6568 FS: 00007f16b6d5a700(0000) GS:ffff8880ba200000(0000) knlGS:0000000000000000 mount_bdev+0x26f/0x330 fs/super.c:1158 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000011980e0 CR3: 00000000a8666000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 erofs_mount+0x6a/0x90 drivers/staging/erofs/super.c:512 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: mount_fs+0x7f/0x2a2 fs/super.c:1261 erofs_read_super drivers/staging/erofs/super.c:439 [inline] erofs_fill_super+0x10b4/0x1168 drivers/staging/erofs/super.c:499 vfs_kern_mount.part.11+0x58/0x3d0 fs/namespace.c:961 vfs_kern_mount fs/namespace.c:951 [inline] do_new_mount fs/namespace.c:2469 [inline] do_mount+0x376/0x2710 fs/namespace.c:2799 mount_bdev+0x26f/0x330 fs/super.c:1158 erofs_mount+0x6a/0x90 drivers/staging/erofs/super.c:512 ksys_mount+0xba/0xe0 fs/namespace.c:3015 __do_sys_mount fs/namespace.c:3029 [inline] __se_sys_mount fs/namespace.c:3026 [inline] __x64_sys_mount+0xb9/0x150 fs/namespace.c:3026 mount_fs+0x7f/0x2a2 fs/super.c:1261 do_syscall_64+0xd0/0x4e0 arch/x86/entry/common.c:293 vfs_kern_mount.part.11+0x58/0x3d0 fs/namespace.c:961 entry_SYSCALL_64_after_hwframe+0x49/0xbe vfs_kern_mount fs/namespace.c:951 [inline] do_new_mount fs/namespace.c:2469 [inline] do_mount+0x376/0x2710 fs/namespace.c:2799 RIP: 0033:0x460baa Code: b8 a6 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 ad 89 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 0f 83 8a 89 fb ff c3 66 0f 1f 84 00 00 00 00 00 RSP: 002b:00007f649b72ca78 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007f649b72cb10 RCX: 0000000000460baa RDX: 0000000020000000 RSI: 0000000020000100 RDI: 00007f649b72cad0 RBP: 00007f649b72cad0 R08: 00007f649b72cb10 R09: 0000000020000000 ksys_mount+0xba/0xe0 fs/namespace.c:3015 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000020000000 __do_sys_mount fs/namespace.c:3029 [inline] __se_sys_mount fs/namespace.c:3026 [inline] __x64_sys_mount+0xb9/0x150 fs/namespace.c:3026 R13: 0000000020000100 R14: 0000000020000200 R15: 0000000020010a00 do_syscall_64+0xd0/0x4e0 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x460baa Code: b8 a6 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 ad 89 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 0f 83 8a 89 fb ff c3 66 0f 1f 84 00 00 00 00 00 RSP: 002b:00007f16b6d59a78 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007f16b6d59b10 RCX: 0000000000460baa RDX: 0000000020000000 RSI: 0000000020000100 RDI: 00007f16b6d59ad0 RBP: 00007f16b6d59ad0 R08: 00007f16b6d59b10 R09: 0000000020000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000020000000 R13: 0000000020000100 R14: 0000000020000200 R15: 0000000020010a00 Modules linked in: ---[ end trace d905268a515ecf86 ]--- RIP: 0010:iput+0x536/0x6b0 fs/inode.c:1571 Code: 48 b8 00 00 00 00 00 fc ff df 48 8b 55 c8 48 c1 ea 03 80 3c 02 00 0f 84 ac fd ff ff 48 8b 7d c8 e8 6f 95 f0 ff e9 9e fd ff ff <0f> 0b 48 89 df e8 60 f9 ff ff 48 8b 7d d0 e8 b7 c4 04 06 e9 2a fe RSP: 0018:ffff88807e8f7a18 EFLAGS: 00010202 erofs: read_super, device -> /dev/loop3 RAX: dffffc0000000000 RBX: ffff88808dbf3268 RCX: 1ffff1101516fdad RDX: 1ffff11011b7e667 RSI: ffff8880a8b7ed48 RDI: ffff88808dbf3268 RBP: ffff88807e8f7a60 R08: ffff8880a8b7ed68 R09: 0000000000000000 erofs: options -> R10: 0000000000000000 R11: 0000000000000000 R12: ffff88808dbf3268 FAULT_INJECTION: forcing a failure. name failslab, interval 1, probability 0, space 0, times 0 R13: ffff8880910a6500 R14: 0000000000000000 R15: ffff8880910a6568 CPU: 1 PID: 10207 Comm: syz-executor.3 Tainted: G D 4.19.166-syzkaller #0 FS: 00007f16b6d5a700(0000) GS:ffff8880ba200000(0000) knlGS:0000000000000000 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x17c/0x22a lib/dump_stack.c:118 fail_dump lib/fault-inject.c:51 [inline] should_fail.cold.2+0x5/0xb lib/fault-inject.c:149 __should_failslab+0xba/0xf0 mm/failslab.c:32 should_failslab+0x9/0x14 mm/slab_common.c:1588 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 slab_pre_alloc_hook mm/slab.h:424 [inline] slab_alloc mm/slab.c:3383 [inline] kmem_cache_alloc+0x47/0x390 mm/slab.c:3557 mempool_alloc_slab+0x3a/0x50 mm/mempool.c:505 mempool_alloc+0x118/0x320 mm/mempool.c:385 CR2: 00007f092802ef58 CR3: 00000000a8666000 CR4: 00000000001406f0 bio_alloc_bioset+0x1a5/0x520 block/bio.c:493 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 bio_alloc include/linux/bio.h:437 [inline] submit_bh_wbc+0xbe/0x6f0 fs/buffer.c:3064 submit_bh fs/buffer.c:3096 [inline] __bread_slow fs/buffer.c:1176 [inline] __bread_gfp+0xc9/0x190 fs/buffer.c:1369 sb_bread include/linux/buffer_head.h:309 [inline] superblock_read drivers/staging/erofs/super.c:102 [inline] erofs_read_super drivers/staging/erofs/super.c:356 [inline] erofs_fill_super+0x1fe/0x1168 drivers/staging/erofs/super.c:499 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 mount_bdev+0x26f/0x330 fs/super.c:1158 erofs_mount+0x6a/0x90 drivers/staging/erofs/super.c:512 mount_fs+0x7f/0x2a2 fs/super.c:1261 vfs_kern_mount.part.11+0x58/0x3d0 fs/namespace.c:961 vfs_kern_mount fs/namespace.c:951 [inline] do_new_mount fs/namespace.c:2469 [inline] do_mount+0x376/0x2710 fs/namespace.c:2799 ksys_mount+0xba/0xe0 fs/namespace.c:3015 __do_sys_mount fs/namespace.c:3029 [inline] __se_sys_mount fs/namespace.c:3026 [inline] __x64_sys_mount+0xb9/0x150 fs/namespace.c:3026 do_syscall_64+0xd0/0x4e0 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x460baa Code: b8 a6 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 ad 89 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 0f 83 8a 89 fb ff c3 66 0f 1f 84 00 00 00 00 00 RSP: 002b:00007f9078f71a78 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007f9078f71b10 RCX: 0000000000460baa RDX: 0000000020000000 RSI: 0000000020000100 RDI: 00007f9078f71ad0 RBP: 00007f9078f71ad0 R08: 00007f9078f71b10 R09: 0000000020000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000020000000 R13: 0000000020000100 R14: 0000000020000200 R15: 0000000020010a00 erofs: unmounted for /dev/loop4