Hello, syzbot found the following issue on: HEAD commit: 06af8679 coredump: Limit what can interrupt coredumps git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=162f99afd00000 kernel config: https://syzkaller.appspot.com/x/.config?x=547a5e42ca601229 dashboard link: https://syzkaller.appspot.com/bug?extid=b42fe626038981fb7bfa compiler: Debian clang version 11.0.1-2 Unfortunately, I don't have any reproducer for this issue yet. IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+b42fe626038981fb7bfa@xxxxxxxxxxxxxxxxxxxxxxxxx ====================================================== WARNING: possible circular locking dependency detected 5.13.0-rc5-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.1/21398 is trying to acquire lock: ffff8881485a6460 (sb_writers#5){.+.+}-{0:0}, at: mnt_want_write+0x3b/0x80 fs/namespace.c:375 but task is already holding lock: ffff888034945bc0 (&iint->mutex){+.+.}-{3:3}, at: process_measurement+0x75a/0x1ba0 security/integrity/ima/ima_main.c:253 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&iint->mutex){+.+.}-{3:3}: lock_acquire+0x17f/0x720 kernel/locking/lockdep.c:5512 __mutex_lock_common+0x1bf/0x3100 kernel/locking/mutex.c:959 __mutex_lock kernel/locking/mutex.c:1104 [inline] mutex_lock_nested+0x1a/0x20 kernel/locking/mutex.c:1119 process_measurement+0x75a/0x1ba0 security/integrity/ima/ima_main.c:253 ima_file_check+0xe0/0x130 security/integrity/ima/ima_main.c:499 do_open fs/namei.c:3363 [inline] path_openat+0x293d/0x39b0 fs/namei.c:3494 do_filp_open+0x221/0x460 fs/namei.c:3521 do_sys_openat2+0x124/0x460 fs/open.c:1187 do_sys_open fs/open.c:1203 [inline] __do_sys_open fs/open.c:1211 [inline] __se_sys_open fs/open.c:1207 [inline] __x64_sys_open+0x221/0x270 fs/open.c:1207 do_syscall_64+0x3f/0xb0 arch/x86/entry/common.c:47 entry_SYSCALL_64_after_hwframe+0x44/0xae -> #0 (sb_writers#5){.+.+}-{0:0}: check_prev_add kernel/locking/lockdep.c:2938 [inline] check_prevs_add+0x4f9/0x5b60 kernel/locking/lockdep.c:3061 validate_chain kernel/locking/lockdep.c:3676 [inline] __lock_acquire+0x4307/0x6040 kernel/locking/lockdep.c:4902 lock_acquire+0x17f/0x720 kernel/locking/lockdep.c:5512 percpu_down_read include/linux/percpu-rwsem.h:51 [inline] __sb_start_write include/linux/fs.h:1763 [inline] sb_start_write+0x4f/0x180 include/linux/fs.h:1833 mnt_want_write+0x3b/0x80 fs/namespace.c:375 ovl_maybe_copy_up+0x117/0x180 fs/overlayfs/copy_up.c:996 ovl_open+0xa2/0x200 fs/overlayfs/file.c:149 do_dentry_open+0x7cb/0x1010 fs/open.c:826 vfs_open fs/open.c:940 [inline] dentry_open+0xc6/0x120 fs/open.c:956 ima_calc_file_hash+0x157/0x1b00 security/integrity/ima/ima_crypto.c:557 ima_collect_measurement+0x283/0x520 security/integrity/ima/ima_api.c:252 process_measurement+0xf79/0x1ba0 security/integrity/ima/ima_main.c:330 ima_file_check+0xe0/0x130 security/integrity/ima/ima_main.c:499 do_open fs/namei.c:3363 [inline] path_openat+0x293d/0x39b0 fs/namei.c:3494 do_filp_open+0x221/0x460 fs/namei.c:3521 do_sys_openat2+0x124/0x460 fs/open.c:1187 do_sys_open fs/open.c:1203 [inline] __do_sys_open fs/open.c:1211 [inline] __se_sys_open fs/open.c:1207 [inline] __x64_sys_open+0x221/0x270 fs/open.c:1207 do_syscall_64+0x3f/0xb0 arch/x86/entry/common.c:47 entry_SYSCALL_64_after_hwframe+0x44/0xae other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&iint->mutex); lock(sb_writers#5); lock(&iint->mutex); lock(sb_writers#5); *** DEADLOCK *** 1 lock held by syz-executor.1/21398: #0: ffff888034945bc0 (&iint->mutex){+.+.}-{3:3}, at: process_measurement+0x75a/0x1ba0 security/integrity/ima/ima_main.c:253 stack backtrace: CPU: 0 PID: 21398 Comm: syz-executor.1 Not tainted 5.13.0-rc5-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:79 [inline] dump_stack+0x202/0x31e lib/dump_stack.c:120 print_circular_bug+0xb17/0xdc0 kernel/locking/lockdep.c:2007 check_noncircular+0x2cc/0x390 kernel/locking/lockdep.c:2129 check_prev_add kernel/locking/lockdep.c:2938 [inline] check_prevs_add+0x4f9/0x5b60 kernel/locking/lockdep.c:3061 validate_chain kernel/locking/lockdep.c:3676 [inline] __lock_acquire+0x4307/0x6040 kernel/locking/lockdep.c:4902 lock_acquire+0x17f/0x720 kernel/locking/lockdep.c:5512 percpu_down_read include/linux/percpu-rwsem.h:51 [inline] __sb_start_write include/linux/fs.h:1763 [inline] sb_start_write+0x4f/0x180 include/linux/fs.h:1833 mnt_want_write+0x3b/0x80 fs/namespace.c:375 ovl_maybe_copy_up+0x117/0x180 fs/overlayfs/copy_up.c:996 ovl_open+0xa2/0x200 fs/overlayfs/file.c:149 do_dentry_open+0x7cb/0x1010 fs/open.c:826 vfs_open fs/open.c:940 [inline] dentry_open+0xc6/0x120 fs/open.c:956 ima_calc_file_hash+0x157/0x1b00 security/integrity/ima/ima_crypto.c:557 ima_collect_measurement+0x283/0x520 security/integrity/ima/ima_api.c:252 process_measurement+0xf79/0x1ba0 security/integrity/ima/ima_main.c:330 ima_file_check+0xe0/0x130 security/integrity/ima/ima_main.c:499 do_open fs/namei.c:3363 [inline] path_openat+0x293d/0x39b0 fs/namei.c:3494 do_filp_open+0x221/0x460 fs/namei.c:3521 do_sys_openat2+0x124/0x460 fs/open.c:1187 do_sys_open fs/open.c:1203 [inline] __do_sys_open fs/open.c:1211 [inline] __se_sys_open fs/open.c:1207 [inline] __x64_sys_open+0x221/0x270 fs/open.c:1207 do_syscall_64+0x3f/0xb0 arch/x86/entry/common.c:47 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x4665d9 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:00007f28cc64c188 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 000000000056bf80 RCX: 00000000004665d9 RDX: 0000000000000000 RSI: 0000000000000003 RDI: 0000000020000200 RBP: 00000000004bfcb9 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf80 R13: 00007ffdd1759cef R14: 00007f28cc64c300 R15: 0000000000022000 overlayfs: upperdir is in-use as upperdir/workdir of another mount, mount with '-o index=off' to override exclusive upperdir protection. --- This report is generated by a bot. 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