bisecting fixing commit since a844dc4c544291470aa69edbe2434b040794e269 building syzkaller on b31eda3df81f62eb7efde0c5d7a9f24ee7e34e6f testing commit a844dc4c544291470aa69edbe2434b040794e269 with gcc (GCC) 8.1.0 kernel signature: 0fedccc8ba9304ce215fbae380855cb8bb3e71d9 run #0: crashed: BUG: corrupted list in p9_fd_request run #1: crashed: BUG: corrupted list in p9_conn_cancel run #2: crashed: BUG: corrupted list in corrupted run #3: crashed: BUG: corrupted list in p9_fd_request run #4: crashed: BUG: corrupted list in p9_fd_request run #5: crashed: BUG: corrupted list in p9_fd_request run #6: crashed: BUG: corrupted list in p9_fd_request run #7: crashed: BUG: corrupted list in p9_fd_request run #8: crashed: BUG: corrupted list in p9_fd_request run #9: crashed: BUG: corrupted list in p9_fd_request testing current HEAD 84f5ad468100f86d70096799e4ee716a17c2962f testing commit 84f5ad468100f86d70096799e4ee716a17c2962f with gcc (GCC) 8.1.0 kernel signature: 0214fb0d9c955b075060c59359ef9e31d22e6c89 run #0: crashed: BUG: corrupted list in p9_fd_request run #1: crashed: BUG: corrupted list in p9_fd_request run #2: crashed: BUG: corrupted list in p9_fd_request run #3: crashed: BUG: corrupted list in p9_fd_request run #4: crashed: BUG: corrupted list in p9_fd_request run #5: crashed: BUG: corrupted list in p9_fd_request run #6: crashed: BUG: corrupted list in p9_fd_request run #7: crashed: BUG: corrupted list in p9_fd_request run #8: crashed: BUG: corrupted list in p9_fd_request run #9: crashed: BUG: corrupted list in corrupted revisions tested: 2, total time: 25m44.918532488s (build: 17m43.011961686s, test: 7m7.337981803s) the crash still happens on HEAD commit msg: Linux 4.14.162 crash: BUG: corrupted list in corrupted IPv6: ADDRCONF(NETDEV_CHANGE): vxcan0: link becomes ready 8021q: adding VLAN 0 to HW filter on device batadv0 list_add double add: new=ffff88808fc58d18, prev=ffff88808fc58d18, next=ffff8880a581c540. ------------[ cut here ]------------ kernel BUG at lib/list_debug.c:31! invalid opcode: 0000 [#1] PREEMPT SMP KASAN Modules linked in: CPU: 1 PID: 11441 Comm: syz-executor.3 Not tainted 4.14.162-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 list_add double add: new=ffff888079df03d8, prev=ffff888079df03d8, next=ffff88808fc63ac0. task: ffff8880a5790240 task.stack: ffff888087320000 RIP: 0010:__list_add_valid+0xaa/0xb0 lib/list_debug.c:29 RSP: 0018:ffff8880873279b0 EFLAGS: 00010282 RAX: 0000000000000058 RBX: ffff8880a581c540 RCX: 0000000000000000 RDX: 0000000000000058 RSI: ffffffff86cc2c20 RDI: ffffed1010e64f2d RBP: ffff8880873279c8 R08: ffff8880a5790b08 R09: 0000000000000000 R10: 0000000000000000 R11: dffffc0000000000 R12: ffff88808fc58d18 R13: ffff88808fc58cf0 R14: ffff88808fc58d18 R15: ffff88808fc58d18 FS: 00007f19b45b1700(0000) GS:ffff8880aed00000(0000) knlGS:0000000000000000 ------------[ cut here ]------------ CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 kernel BUG at lib/list_debug.c:31! CR2: 00007ff26addb000 CR3: 000000007eec7000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __list_add include/linux/list.h:60 [inline] list_add_tail include/linux/list.h:93 [inline] p9_fd_request+0xdd/0x2b0 net/9p/trans_fd.c:679 p9_client_rpc+0x1fd/0xe80 net/9p/client.c:774 p9_client_clunk+0x7b/0x120 net/9p/client.c:1507 v9fs_dentry_release+0x5e/0xc0 fs/9p/vfs_dentry.c:73 __dentry_kill+0x330/0x540 fs/dcache.c:596 dentry_kill fs/dcache.c:632 [inline] dput.part.27+0x49a/0x610 fs/dcache.c:847 dput fs/dcache.c:811 [inline] do_one_tree+0x36/0x40 fs/dcache.c:1507 shrink_dcache_for_umount+0x56/0x110 fs/dcache.c:1521 generic_shutdown_super+0x61/0x330 fs/super.c:431 kill_anon_super+0x37/0x50 fs/super.c:1006 v9fs_kill_super+0x39/0x90 fs/9p/vfs_super.c:230 deactivate_locked_super+0x62/0xb0 fs/super.c:319 deactivate_super+0x7d/0x90 fs/super.c:350 cleanup_mnt+0x9f/0x130 fs/namespace.c:1183 __cleanup_mnt+0xd/0x10 fs/namespace.c:1190 task_work_run+0xe5/0x170 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:191 [inline] exit_to_usermode_loop+0x16a/0x1b0 arch/x86/entry/common.c:164 prepare_exit_to_usermode arch/x86/entry/common.c:199 [inline] syscall_return_slowpath arch/x86/entry/common.c:270 [inline] do_syscall_64+0x416/0x5b0 arch/x86/entry/common.c:297 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x45a6f9 RSP: 002b:00007f19b45b0c78 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 0000000000000002 RCX: 000000000045a6f9 RDX: 0000000000000000 RSI: 000000000000000b RDI: 0000000020000140 RBP: 000000000075bfc8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f19b45b16d4 R13: 00000000004cb211 R14: 00000000004e4988 R15: 00000000ffffffff Code: 75 e8 eb a9 48 89 f7 48 89 75 e8 e8 71 5b 7f fe 48 8b 75 e8 eb bb 48 89 f2 48 89 d9 4c 89 e6 48 c7 c7 e0 c5 03 87 e8 73 e2 44 fe <0f> 0b 0f 1f 40 00 48 b8 00 00 00 00 00 fc ff df 55 48 89 e5 41 RIP: __list_add_valid+0xaa/0xb0 lib/list_debug.c:29 RSP: ffff8880873279b0 invalid opcode: 0000 [#2] PREEMPT SMP KASAN ---[ end trace c5952f2ab388d0be ]--- Modules linked in: CPU: 0 PID: 11458 Comm: syz-executor.0 Tainted: G D 4.14.162-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011