[CC: linux-intergrity] On Tue, 15 Jun 2021 at 18:59, syzbot <syzbot+b42fe626038981fb7bfa@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote: > > 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. It may contain errors. > See https://goo.gl/tpsmEJ for more information about syzbot. > syzbot engineers can be reached at syzkaller@xxxxxxxxxxxxxxxx. > > syzbot will keep track of this issue. See: > https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
