bisecting fixing commit since 1bab61d3e8cd96f2badf515dcb06e4e1029bc017 building syzkaller on 4afdfa205b55633e7eb9db03a9d099d7aa324801 testing commit 1bab61d3e8cd96f2badf515dcb06e4e1029bc017 with gcc (GCC) 8.1.0 kernel signature: 53e35ac50d8212a49c8d9380639d0eea18dff2433b2c7eea97cb699bf5378901 run #0: crashed: WARNING in inc_nlink run #1: crashed: WARNING in inc_nlink run #2: crashed: WARNING in corrupted run #3: crashed: WARNING in inc_nlink run #4: crashed: WARNING in inc_nlink run #5: crashed: WARNING in inc_nlink run #6: crashed: WARNING in inc_nlink run #7: crashed: WARNING in inc_nlink run #8: crashed: WARNING in inc_nlink run #9: crashed: WARNING in inc_nlink testing current HEAD 17a87580a8856170d59aab302226811a4ae69149 testing commit 17a87580a8856170d59aab302226811a4ae69149 with gcc (GCC) 8.1.0 kernel signature: 86868eb36d9ece21a9a15fa1db6e22c0f5e7d4b397513f684d9d220b42b2a280 run #0: crashed: WARNING in corrupted run #1: crashed: WARNING in inc_nlink run #2: crashed: WARNING in inc_nlink run #3: crashed: WARNING in inc_nlink run #4: crashed: WARNING in inc_nlink run #5: crashed: WARNING in inc_nlink run #6: crashed: WARNING in inc_nlink run #7: crashed: WARNING in inc_nlink run #8: crashed: WARNING in inc_nlink run #9: crashed: WARNING in corrupted revisions tested: 2, total time: 26m57.51183072s (build: 20m1.690414141s, test: 5m57.119935929s) the crash still happens on HEAD commit msg: Linux 4.19.133 crash: WARNING in corrupted IPv6: ADDRCONF(NETDEV_CHANGE): veth1_to_batadv: link becomes ready MINIX-fs: mounting unchecked file system, running fsck is recommended MINIX-fs: mounting unchecked file system, running fsck is recommended ------------[ cut here ]------------ ------------[ cut here ]------------ WARNING: CPU: 0 PID: 7872 at fs/inode.c:343 inc_nlink.cold.15+0xc/0x13 fs/inode.c:343 WARNING: CPU: 1 PID: 7879 at fs/inode.c:343 inc_nlink.cold.15+0xc/0x13 fs/inode.c:343 Kernel panic - not syncing: panic_on_warn set ... Modules linked in: CPU: 0 PID: 7872 Comm: syz-executor.0 Not tainted 4.19.133-syzkaller #0 CPU: 1 PID: 7879 Comm: syz-executor.1 Not tainted 4.19.133-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: RIP: 0010:inc_nlink.cold.15+0xc/0x13 fs/inode.c:343 __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x17c/0x22a lib/dump_stack.c:118 Code: 10 75 08 48 89 df e8 3a c9 ff ff 5b 41 5c 5d c3 e8 60 cd f0 ff eb e2 e8 79 cd f0 ff eb ac 48 c7 c7 80 b4 33 87 e8 cb 7f ad ff <0f> 0b e9 f2 96 ff ff 48 8d 7b 40 b8 ff ff 37 00 48 89 fa 48 c1 e0 RSP: 0018:ffff888084917d40 EFLAGS: 00010286 panic+0x1cd/0x375 kernel/panic.c:186 RAX: 0000000000000024 RBX: ffff88807602e9a0 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff87677ce0 RDI: ffffffff8a196a60 __warn.cold.7+0x1b/0x3e kernel/panic.c:541 RBP: ffff888084917d60 R08: ffffed1015d65081 R09: ffffed1015d65080 R10: ffffed1015d65080 R11: ffff8880aeb28407 R12: ffff88807602e9e8 report_bug+0x1a4/0x200 lib/bug.c:186 R13: 1ffff11010922fae R14: ffff8880824b4e40 R15: ffff8880824b4e98 FS: 00007f0bc6e64700(0000) GS:ffff8880aeb00000(0000) knlGS:0000000000000000 fixup_bug arch/x86/kernel/traps.c:178 [inline] do_error_trap+0x200/0x350 arch/x86/kernel/traps.c:296 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000000043e2e0 CR3: 000000008b3a9000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: inode_inc_link_count include/linux/fs.h:2098 [inline] minix_mkdir+0x68/0x160 fs/minix/namei.c:117 do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:316 invalid_op+0x14/0x20 arch/x86/entry/entry_64.S:1038 RIP: 0010:inc_nlink.cold.15+0xc/0x13 fs/inode.c:343 vfs_mkdir+0x37f/0x620 fs/namei.c:3819 Code: 10 75 08 48 89 df e8 3a c9 ff ff 5b 41 5c 5d c3 e8 60 cd f0 ff eb e2 e8 79 cd f0 ff eb ac 48 c7 c7 80 b4 33 87 e8 cb 7f ad ff <0f> 0b e9 f2 96 ff ff 48 8d 7b 40 b8 ff ff 37 00 48 89 fa 48 c1 e0 do_mkdirat+0x1c2/0x220 fs/namei.c:3842 RSP: 0018:ffff8880822e7d40 EFLAGS: 00010286 RAX: 0000000000000024 RBX: ffff88807d3fe960 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff87677ce0 RDI: ffffffff8a196a60 RBP: ffff8880822e7d60 R08: ffffed1015d45081 R09: ffffed1015d45080 R10: ffffed1015d45080 R11: ffff8880aea28407 R12: ffff88807d3fe9a8 R13: 1ffff1101045cfae R14: ffff8880824ad9e0 R15: ffff8880824ada38 inode_inc_link_count include/linux/fs.h:2098 [inline] minix_mkdir+0x68/0x160 fs/minix/namei.c:117 __do_sys_mkdir fs/namei.c:3858 [inline] __se_sys_mkdir fs/namei.c:3856 [inline] __x64_sys_mkdir+0x57/0x80 fs/namei.c:3856 do_syscall_64+0xd0/0x4e0 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45caa9 vfs_mkdir+0x37f/0x620 fs/namei.c:3819 Code: 8d b6 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 5b b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 do_mkdirat+0x1c2/0x220 fs/namei.c:3842 RSP: 002b:00007f0bc6e63c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000053 RAX: ffffffffffffffda RBX: 00000000004f5bc0 RCX: 000000000045caa9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020000240 RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000000000000734 R14: 00000000004c2580 R15: 00007f0bc6e646d4 irq event stamp: 2260 __do_sys_mkdir fs/namei.c:3858 [inline] __se_sys_mkdir fs/namei.c:3856 [inline] __x64_sys_mkdir+0x57/0x80 fs/namei.c:3856 hardirqs last enabled at (2259): [] __raw_spin_unlock_irq include/linux/spinlock_api_smp.h:168 [inline] hardirqs last enabled at (2259): [] _raw_spin_unlock_irq+0x27/0x90 kernel/locking/spinlock.c:192 do_syscall_64+0xd0/0x4e0 arch/x86/entry/common.c:293 hardirqs last disabled at (2260): [] trace_hardirqs_off_thunk+0x1a/0x1c entry_SYSCALL_64_after_hwframe+0x49/0xbe softirqs last enabled at (2108): [] __do_softirq+0x643/0x92d kernel/softirq.c:318 RIP: 0033:0x45caa9 softirqs last disabled at (1989): [] invoke_softirq kernel/softirq.c:372 [inline] softirqs last disabled at (1989): [] irq_exit+0x17f/0x1c0 kernel/softirq.c:412 Code: 8d b6 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 5b b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 ---[ end trace 0a4c5a392d1c88c7 ]--- RSP: 002b:00007fb7bbdd6c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000053 MINIX-fs: mounting unchecked file system, running fsck is recommended RAX: ffffffffffffffda RBX: 00000000004f5bc0 RCX: 000000000045caa9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020000240 RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000000000000734 R14: 00000000004c2580 R15: 00007fb7bbdd76d4 Kernel Offset: disabled Rebooting in 86400 seconds..