ci2 starts bisection 2023-06-14 11:52:30.233362283 +0000 UTC m=+58945.881793830 bisecting fixing commit since bf4ad6fa4e5332e53913b073d0219319a4091619 building syzkaller on 2b9ba477a18ed0cc53e6b29a9641292709a7ba24 ensuring issue is reproducible on original commit bf4ad6fa4e5332e53913b073d0219319a4091619 testing commit bf4ad6fa4e5332e53913b073d0219319a4091619 gcc compiler: Debian clang version 15.0.7, GNU ld (GNU Binutils for Debian) 2.35.2 kernel signature: c42e12cb1533bd722fc7bf0b4f6393cde75df4235eafad4b6d3035cc76421702 all runs: crashed: possible deadlock in mnt_want_write testing current HEAD ca87e77a2ef8b298aa9f69658d5898e72ee450fe testing commit ca87e77a2ef8b298aa9f69658d5898e72ee450fe gcc compiler: Debian clang version 15.0.7, GNU ld (GNU Binutils for Debian) 2.35.2 kernel signature: 37cba237a1ffe49a8c7597a8f5e7a546df5b43f1aca12d1688fa51695ca60862 all runs: crashed: possible deadlock in mnt_want_write crash still not fixed/happens on the oldest tested release revisions tested: 2, total time: 40m52.859215984s (build: 26m42.206457419s, test: 7m34.585789867s) crash still not fixed on HEAD or HEAD had kernel test errors commit msg: Linux 6.1.34 crash: possible deadlock in mnt_want_write ====================================================== WARNING: possible circular locking dependency detected 6.1.34-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.0/3974 is trying to acquire lock: ffff88807f1d6460 (sb_writers#4){.+.+}-{0:0}, at: mnt_want_write+0x36/0x70 fs/namespace.c:393 but task is already holding lock: ffff888025ebece0 (&iint->mutex){+.+.}-{3:3}, at: process_measurement+0x65b/0x1520 security/integrity/ima/ima_main.c:260 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&iint->mutex){+.+.}-{3:3}: lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5669 __mutex_lock_common+0x1d4/0x2520 kernel/locking/mutex.c:603 __mutex_lock kernel/locking/mutex.c:747 [inline] mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:799 process_measurement+0x65b/0x1520 security/integrity/ima/ima_main.c:260 ima_file_check+0xe8/0x160 security/integrity/ima/ima_main.c:520 do_open fs/namei.c:3559 [inline] path_openat+0x2247/0x27e0 fs/namei.c:3714 do_filp_open+0x226/0x430 fs/namei.c:3741 do_sys_openat2+0x10b/0x420 fs/open.c:1318 do_sys_open fs/open.c:1334 [inline] __do_sys_openat fs/open.c:1350 [inline] __se_sys_openat fs/open.c:1345 [inline] __x64_sys_openat+0x209/0x250 fs/open.c:1345 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd -> #0 (sb_writers#4){.+.+}-{0:0}: check_prev_add kernel/locking/lockdep.c:3098 [inline] check_prevs_add kernel/locking/lockdep.c:3217 [inline] validate_chain+0x1667/0x58e0 kernel/locking/lockdep.c:3832 __lock_acquire+0x125b/0x1f80 kernel/locking/lockdep.c:5056 lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5669 percpu_down_read include/linux/percpu-rwsem.h:51 [inline] __sb_start_write include/linux/fs.h:1832 [inline] sb_start_write+0x47/0x130 include/linux/fs.h:1907 mnt_want_write+0x36/0x70 fs/namespace.c:393 ovl_maybe_copy_up+0xb1/0x100 fs/overlayfs/copy_up.c:1087 ovl_open+0xee/0x2a0 fs/overlayfs/file.c:153 do_dentry_open+0x5fc/0xdd0 fs/open.c:882 vfs_open fs/open.c:1013 [inline] dentry_open+0xb5/0xf0 fs/open.c:1029 ima_calc_file_hash+0x12d/0x1670 security/integrity/ima/ima_crypto.c:558 ima_collect_measurement+0x3c4/0x7d0 security/integrity/ima/ima_api.c:292 process_measurement+0xb98/0x1520 security/integrity/ima/ima_main.c:337 ima_file_check+0xe8/0x160 security/integrity/ima/ima_main.c:520 do_open fs/namei.c:3559 [inline] path_openat+0x2247/0x27e0 fs/namei.c:3714 do_filp_open+0x226/0x430 fs/namei.c:3741 do_sys_openat2+0x10b/0x420 fs/open.c:1318 do_sys_open fs/open.c:1334 [inline] __do_sys_openat fs/open.c:1350 [inline] __se_sys_openat fs/open.c:1345 [inline] __x64_sys_openat+0x209/0x250 fs/open.c:1345 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&iint->mutex); lock(sb_writers#4); lock(&iint->mutex); lock(sb_writers#4); *** DEADLOCK *** 1 lock held by syz-executor.0/3974: #0: ffff888025ebece0 (&iint->mutex){+.+.}-{3:3}, at: process_measurement+0x65b/0x1520 security/integrity/ima/ima_main.c:260 stack backtrace: CPU: 1 PID: 3974 Comm: syz-executor.0 Not tainted 6.1.34-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/27/2023 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x163/0x213 lib/dump_stack.c:106 check_noncircular+0x2fa/0x3b0 kernel/locking/lockdep.c:2178 check_prev_add kernel/locking/lockdep.c:3098 [inline] check_prevs_add kernel/locking/lockdep.c:3217 [inline] validate_chain+0x1667/0x58e0 kernel/locking/lockdep.c:3832 __lock_acquire+0x125b/0x1f80 kernel/locking/lockdep.c:5056 lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5669 percpu_down_read include/linux/percpu-rwsem.h:51 [inline] __sb_start_write include/linux/fs.h:1832 [inline] sb_start_write+0x47/0x130 include/linux/fs.h:1907 mnt_want_write+0x36/0x70 fs/namespace.c:393 ovl_maybe_copy_up+0xb1/0x100 fs/overlayfs/copy_up.c:1087 ovl_open+0xee/0x2a0 fs/overlayfs/file.c:153 do_dentry_open+0x5fc/0xdd0 fs/open.c:882 vfs_open fs/open.c:1013 [inline] dentry_open+0xb5/0xf0 fs/open.c:1029 ima_calc_file_hash+0x12d/0x1670 security/integrity/ima/ima_crypto.c:558 ima_collect_measurement+0x3c4/0x7d0 security/integrity/ima/ima_api.c:292 process_measurement+0xb98/0x1520 security/integrity/ima/ima_main.c:337 ima_file_check+0xe8/0x160 security/integrity/ima/ima_main.c:520 do_open fs/namei.c:3559 [inline] path_openat+0x2247/0x27e0 fs/namei.c:3714 do_filp_open+0x226/0x430 fs/namei.c:3741 do_sys_openat2+0x10b/0x420 fs/open.c:1318 do_sys_open fs/open.c:1334 [inline] __do_sys_openat fs/open.c:1350 [inline] __se_sys_openat fs/open.c:1345 [inline] __x64_sys_openat+0x209/0x250 fs/open.c:1345 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f5c5a28c169 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 19 00 00 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 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f5c5b000168 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f5c5a3abf80 RCX: 00007f5c5a28c169 RDX: 0000000000000003 RSI: 0000000020000340 RDI: 0000000000000006 RBP: 00007f5c5a2e7ca1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffe7b4a55af R14: 00007f5c5b000300 R15: 0000000000022000