Hello, syzbot found the following issue on: HEAD commit: a349e4c6 Merge tag 'xfs-5.10-fixes-7' of git://git.kernel... git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=11813299500000 kernel config: https://syzkaller.appspot.com/x/.config?x=a521022462477aea dashboard link: https://syzkaller.appspot.com/bug?extid=c18f2f6a7b08c51e3025 compiler: gcc (GCC) 10.1.0-syz 20200507 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+c18f2f6a7b08c51e3025@xxxxxxxxxxxxxxxxxxxxxxxxx ====================================================== WARNING: possible circular locking dependency detected 5.10.0-rc4-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.4/12280 is trying to acquire lock: ffff8881480c8460 (sb_writers#4){.+.+}-{0:0}, at: ovl_maybe_copy_up+0x11f/0x190 fs/overlayfs/copy_up.c:990 but task is already holding lock: ffff888011c1a740 (&iint->mutex){+.+.}-{3:3}, at: process_measurement+0x363/0x1760 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}: __mutex_lock_common kernel/locking/mutex.c:956 [inline] __mutex_lock+0x134/0x10e0 kernel/locking/mutex.c:1103 process_measurement+0x363/0x1760 security/integrity/ima/ima_main.c:253 ima_file_check+0xb9/0x100 security/integrity/ima/ima_main.c:498 do_open fs/namei.c:3254 [inline] path_openat+0x154d/0x2730 fs/namei.c:3369 do_filp_open+0x17e/0x3c0 fs/namei.c:3396 do_sys_openat2+0x16d/0x420 fs/open.c:1168 do_sys_open fs/open.c:1184 [inline] __do_sys_openat fs/open.c:1200 [inline] __se_sys_openat fs/open.c:1195 [inline] __x64_sys_openat+0x13f/0x1f0 fs/open.c:1195 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 -> #0 (sb_writers#4){.+.+}-{0:0}: check_prev_add kernel/locking/lockdep.c:2866 [inline] check_prevs_add kernel/locking/lockdep.c:2991 [inline] validate_chain kernel/locking/lockdep.c:3606 [inline] __lock_acquire+0x2ca6/0x5c00 kernel/locking/lockdep.c:4830 lock_acquire kernel/locking/lockdep.c:5435 [inline] lock_acquire+0x2a3/0x8c0 kernel/locking/lockdep.c:5400 percpu_down_read include/linux/percpu-rwsem.h:51 [inline] __sb_start_write include/linux/fs.h:1594 [inline] sb_start_write include/linux/fs.h:1664 [inline] mnt_want_write+0x69/0x3d0 fs/namespace.c:354 ovl_maybe_copy_up+0x11f/0x190 fs/overlayfs/copy_up.c:990 ovl_open+0xba/0x270 fs/overlayfs/file.c:154 do_dentry_open+0x4b9/0x11b0 fs/open.c:817 vfs_open fs/open.c:931 [inline] dentry_open+0x132/0x1d0 fs/open.c:947 ima_calc_file_hash+0x32b/0x5a0 security/integrity/ima/ima_crypto.c:557 ima_collect_measurement+0x4ca/0x570 security/integrity/ima/ima_api.c:250 process_measurement+0xca6/0x1760 security/integrity/ima/ima_main.c:330 ima_file_check+0xb9/0x100 security/integrity/ima/ima_main.c:498 do_open fs/namei.c:3254 [inline] path_openat+0x154d/0x2730 fs/namei.c:3369 do_filp_open+0x17e/0x3c0 fs/namei.c:3396 do_sys_openat2+0x16d/0x420 fs/open.c:1168 do_sys_open fs/open.c:1184 [inline] __do_sys_open fs/open.c:1192 [inline] __se_sys_open fs/open.c:1188 [inline] __x64_sys_open+0x119/0x1c0 fs/open.c:1188 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 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.4/12280: #0: ffff888011c1a740 (&iint->mutex){+.+.}-{3:3}, at: process_measurement+0x363/0x1760 security/integrity/ima/ima_main.c:253 stack backtrace: CPU: 0 PID: 12280 Comm: syz-executor.4 Not tainted 5.10.0-rc4-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+0x107/0x163 lib/dump_stack.c:118 check_noncircular+0x25f/0x2e0 kernel/locking/lockdep.c:2115 check_prev_add kernel/locking/lockdep.c:2866 [inline] check_prevs_add kernel/locking/lockdep.c:2991 [inline] validate_chain kernel/locking/lockdep.c:3606 [inline] __lock_acquire+0x2ca6/0x5c00 kernel/locking/lockdep.c:4830 lock_acquire kernel/locking/lockdep.c:5435 [inline] lock_acquire+0x2a3/0x8c0 kernel/locking/lockdep.c:5400 percpu_down_read include/linux/percpu-rwsem.h:51 [inline] __sb_start_write include/linux/fs.h:1594 [inline] sb_start_write include/linux/fs.h:1664 [inline] mnt_want_write+0x69/0x3d0 fs/namespace.c:354 ovl_maybe_copy_up+0x11f/0x190 fs/overlayfs/copy_up.c:990 ovl_open+0xba/0x270 fs/overlayfs/file.c:154 do_dentry_open+0x4b9/0x11b0 fs/open.c:817 vfs_open fs/open.c:931 [inline] dentry_open+0x132/0x1d0 fs/open.c:947 ima_calc_file_hash+0x32b/0x5a0 security/integrity/ima/ima_crypto.c:557 ima_collect_measurement+0x4ca/0x570 security/integrity/ima/ima_api.c:250 process_measurement+0xca6/0x1760 security/integrity/ima/ima_main.c:330 ima_file_check+0xb9/0x100 security/integrity/ima/ima_main.c:498 do_open fs/namei.c:3254 [inline] path_openat+0x154d/0x2730 fs/namei.c:3369 do_filp_open+0x17e/0x3c0 fs/namei.c:3396 do_sys_openat2+0x16d/0x420 fs/open.c:1168 do_sys_open fs/open.c:1184 [inline] __do_sys_open fs/open.c:1192 [inline] __se_sys_open fs/open.c:1188 [inline] __x64_sys_open+0x119/0x1c0 fs/open.c:1188 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45deb9 Code: 0d b4 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 db b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fccb9104c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 00000000000221c0 RCX: 000000000045deb9 RDX: 0000000000000000 RSI: 0000000000000003 RDI: 0000000020000040 RBP: 000000000118bf60 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118bf2c R13: 00007ffc3967e2bf R14: 00007fccb91059c0 R15: 000000000118bf2c 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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