bisecting fixing commit since 0c88e405c97ed1828443b67891e6d4bb6e56cd4e building syzkaller on a0092f9dfdd33924abe5cf5565e4ec4748217c7b testing commit 0c88e405c97ed1828443b67891e6d4bb6e56cd4e compiler: gcc version 8.4.1 20210217 (GCC) kernel signature: 493125d88416c7a9787a08bcac7eb9b9bfe993b185df0b469942e2fb61fc7b11 run #0: crashed: WARNING in inc_nlink 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 inc_nlink run #10: crashed: WARNING in inc_nlink run #11: crashed: WARNING in inc_nlink run #12: crashed: WARNING in inc_nlink run #13: crashed: WARNING in inc_nlink run #14: crashed: WARNING in corrupted run #15: crashed: WARNING in inc_nlink run #16: crashed: WARNING in inc_nlink run #17: crashed: WARNING in inc_nlink run #18: crashed: WARNING in inc_nlink run #19: crashed: WARNING in inc_nlink testing current HEAD b172b44fcb1771e083aad806fa96f3f60e2ddfac testing commit b172b44fcb1771e083aad806fa96f3f60e2ddfac compiler: gcc version 8.4.1 20210217 (GCC) kernel signature: e4d8b696210e7bb7decd87e4543f673bce1c2a34de2ddaec63d819ba9e29eec7 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 inc_nlink revisions tested: 2, total time: 26m2.962379269s (build: 18m42.746783964s, test: 6m43.682792256s) the crash still happens on HEAD commit msg: Linux 4.19.206 crash: WARNING in inc_nlink IPv6: ADDRCONF(NETDEV_UP): wlan0: link is not ready VFS: Found a V7 FS (block size = 512) on device loop2 wlan0: Created IBSS using preconfigured BSSID 50:50:50:50:50:50 wlan0: Creating new IBSS network, BSSID 50:50:50:50:50:50 ------------[ cut here ]------------ WARNING: CPU: 1 PID: 9874 at fs/inode.c:343 inc_nlink.cold.15+0xc/0x13 fs/inode.c:343 Kernel panic - not syncing: panic_on_warn set ... IPv6: ADDRCONF(NETDEV_CHANGE): wlan0: link becomes ready CPU: 1 PID: 9874 Comm: syz-executor.2 Not tainted 4.19.206-syzkaller #0 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/0x226 lib/dump_stack.c:118 IPv6: ADDRCONF(NETDEV_UP): wlan1: link is not ready panic+0x1cd/0x375 kernel/panic.c:186 __warn.cold.7+0x1b/0x36 kernel/panic.c:541 wlan1: Created IBSS using preconfigured BSSID 50:50:50:50:50:50 report_bug+0x1a1/0x200 lib/bug.c:183 fixup_bug arch/x86/kernel/traps.c:178 [inline] fixup_bug arch/x86/kernel/traps.c:173 [inline] do_error_trap+0x200/0x350 arch/x86/kernel/traps.c:296 wlan1: Creating new IBSS network, BSSID 50:50:50:50:50:50 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 Code: fb 03 ff ff 0f 0b e9 dc 04 17 fa 48 c7 c7 a0 8a 13 88 e8 e8 03 ff ff 0f 0b e9 19 05 17 fa 48 c7 c7 c0 92 13 88 e8 d5 03 ff ff <0f> 0b e9 9f 1e 17 fa 48 8d 7b 40 b8 ff ff 37 00 48 89 fa 48 c1 e0 RSP: 0018:ffff88809b907d98 EFLAGS: 00010282 RAX: 0000000000000024 RBX: ffff88808ca01948 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff885023e0 RDI: ffffffff8bad9720 RBP: ffff88809b907db8 R08: ffffed1017464ea9 R09: ffffed1017464ea8 R10: ffffed1017464ea8 R11: ffff8880ba327547 R12: ffff88808ca01990 R13: ffff88808eaeb5c0 R14: 00000000000000a8 R15: ffff88808eaeb618 IPv6: ADDRCONF(NETDEV_CHANGE): wlan1: link becomes ready inode_inc_link_count include/linux/fs.h:2101 [inline] sysv_mkdir+0x18/0x100 fs/sysv/namei.c:131 vfs_mkdir+0x37f/0x620 fs/namei.c:3819 do_mkdirat+0x1c2/0x220 fs/namei.c:3842 __do_sys_mkdirat fs/namei.c:3853 [inline] __se_sys_mkdirat fs/namei.c:3851 [inline] __x64_sys_mkdirat+0x71/0xb0 fs/namei.c:3851 do_syscall_64+0xd0/0x4e0 arch/x86/entry/common.c:293 VFS: Found a V7 FS (block size = 512) on device loop0 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x465889 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fc51fc72188 EFLAGS: 00000246 ORIG_RAX: 0000000000000102 RAX: ffffffffffffffda RBX: 000000000055bf00 RCX: 0000000000465889 RDX: 00000000000000b8 RSI: 0000000020000040 RDI: 0000000000000005 ieee80211 phy8: Selected rate control algorithm 'minstrel_ht' RBP: 00000000004af68d R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000055bf00 R13: 00007ffc2a0adbbf R14: 00007fc51fc72300 R15: 0000000000022000 Kernel Offset: disabled Rebooting in 86400 seconds..