syzbot has found a reproducer for the following issue on: HEAD commit: 14f8db1c0f9a Merge branch 'for-next/core' into for-kernelci git tree: git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci console output: https://syzkaller.appspot.com/x/log.txt?x=115bdcf8280000 kernel config: https://syzkaller.appspot.com/x/.config?x=a837a8ba7e88bb45 dashboard link: https://syzkaller.appspot.com/bug?extid=aacb82fca60873422114 compiler: Debian clang version 15.0.7, GNU ld (GNU Binutils for Debian) 2.35.2 userspace arch: arm64 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1405a2b4280000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=17bd276fc80000 Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/ad6ce516eed3/disk-14f8db1c.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/1f38c2cc7667/vmlinux-14f8db1c.xz kernel image: https://storage.googleapis.com/syzbot-assets/d795115eee39/Image-14f8db1c.gz.xz mounted in repro: https://storage.googleapis.com/syzbot-assets/b9312932adf4/mount_0.gz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+aacb82fca60873422114@xxxxxxxxxxxxxxxxxxxxxxxxx ====================================================== WARNING: possible circular locking dependency detected 6.3.0-rc7-syzkaller-g14f8db1c0f9a #0 Not tainted ------------------------------------------------------ syz-executor396/5961 is trying to acquire lock: ffff0000d9e5c0e0 (&type->s_umount_key#29){++++}-{3:3}, at: __do_sys_quotactl_fd fs/quota/quota.c:999 [inline] ffff0000d9e5c0e0 (&type->s_umount_key#29){++++}-{3:3}, at: __se_sys_quotactl_fd fs/quota/quota.c:972 [inline] ffff0000d9e5c0e0 (&type->s_umount_key#29){++++}-{3:3}, at: __arm64_sys_quotactl_fd+0x30c/0x4a4 fs/quota/quota.c:972 but task is already holding lock: ffff0000d9e5c460 (sb_writers#3){.+.+}-{0:0}, at: mnt_want_write+0x44/0x9c fs/namespace.c:394 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (sb_writers#3){.+.+}-{0:0}: percpu_down_read include/linux/percpu-rwsem.h:51 [inline] __sb_start_write include/linux/fs.h:1477 [inline] sb_start_write include/linux/fs.h:1552 [inline] write_mmp_block+0xe4/0xb70 fs/ext4/mmp.c:50 ext4_multi_mount_protect+0x2f8/0x8c8 fs/ext4/mmp.c:343 __ext4_remount fs/ext4/super.c:6543 [inline] ext4_reconfigure+0x2180/0x2928 fs/ext4/super.c:6642 reconfigure_super+0x328/0x738 fs/super.c:956 do_remount fs/namespace.c:2704 [inline] path_mount+0xc0c/0xe04 fs/namespace.c:3364 do_mount fs/namespace.c:3385 [inline] __do_sys_mount fs/namespace.c:3594 [inline] __se_sys_mount fs/namespace.c:3571 [inline] __arm64_sys_mount+0x45c/0x594 fs/namespace.c:3571 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x2c0 arch/arm64/kernel/syscall.c:52 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142 do_el0_svc+0x64/0x198 arch/arm64/kernel/syscall.c:193 el0_svc+0x4c/0x15c arch/arm64/kernel/entry-common.c:637 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655 el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:591 -> #0 (&type->s_umount_key#29){++++}-{3:3}: check_prev_add kernel/locking/lockdep.c:3098 [inline] check_prevs_add kernel/locking/lockdep.c:3217 [inline] validate_chain kernel/locking/lockdep.c:3832 [inline] __lock_acquire+0x3338/0x764c kernel/locking/lockdep.c:5056 lock_acquire+0x238/0x718 kernel/locking/lockdep.c:5669 down_read+0x50/0x6c kernel/locking/rwsem.c:1520 __do_sys_quotactl_fd fs/quota/quota.c:999 [inline] __se_sys_quotactl_fd fs/quota/quota.c:972 [inline] __arm64_sys_quotactl_fd+0x30c/0x4a4 fs/quota/quota.c:972 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x2c0 arch/arm64/kernel/syscall.c:52 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142 do_el0_svc+0x64/0x198 arch/arm64/kernel/syscall.c:193 el0_svc+0x4c/0x15c arch/arm64/kernel/entry-common.c:637 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655 el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:591 other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(sb_writers#3); lock(&type->s_umount_key#29); lock(sb_writers#3); lock(&type->s_umount_key#29); *** DEADLOCK *** 1 lock held by syz-executor396/5961: #0: ffff0000d9e5c460 (sb_writers#3){.+.+}-{0:0}, at: mnt_want_write+0x44/0x9c fs/namespace.c:394 stack backtrace: CPU: 0 PID: 5961 Comm: syz-executor396 Not tainted 6.3.0-rc7-syzkaller-g14f8db1c0f9a #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/30/2023 Call trace: dump_backtrace+0x1b8/0x1e4 arch/arm64/kernel/stacktrace.c:233 show_stack+0x2c/0x44 arch/arm64/kernel/stacktrace.c:240 __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd0/0x124 lib/dump_stack.c:106 dump_stack+0x1c/0x28 lib/dump_stack.c:113 print_circular_bug+0x150/0x1b8 kernel/locking/lockdep.c:2056 check_noncircular+0x2cc/0x378 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 kernel/locking/lockdep.c:3832 [inline] __lock_acquire+0x3338/0x764c kernel/locking/lockdep.c:5056 lock_acquire+0x238/0x718 kernel/locking/lockdep.c:5669 down_read+0x50/0x6c kernel/locking/rwsem.c:1520 __do_sys_quotactl_fd fs/quota/quota.c:999 [inline] __se_sys_quotactl_fd fs/quota/quota.c:972 [inline] __arm64_sys_quotactl_fd+0x30c/0x4a4 fs/quota/quota.c:972 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x2c0 arch/arm64/kernel/syscall.c:52 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142 do_el0_svc+0x64/0x198 arch/arm64/kernel/syscall.c:193 el0_svc+0x4c/0x15c arch/arm64/kernel/entry-common.c:637 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655 el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:591 --- If you want syzbot to run the reproducer, reply with: #syz test: git://repo/address.git branch-or-commit-hash If you attach or paste a git patch, syzbot will apply it before testing.
