Hello, syzbot found the following issue on: HEAD commit: 50c8770a42fa Add linux-next specific files for 20250702 git tree: linux-next console+strace: https://syzkaller.appspot.com/x/log.txt?x=152d348c580000 kernel config: https://syzkaller.appspot.com/x/.config?x=70c16e4e191115d4 dashboard link: https://syzkaller.appspot.com/bug?extid=6d7771315ecb9233f395 compiler: Debian clang version 20.1.6 (++20250514063057+1e4d39e07757-1~exp1~20250514183223.118), Debian LLD 20.1.6 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=106bd770580000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=164b048c580000 Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/3d4ef6bedc5b/disk-50c8770a.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/15b7565dc0ef/vmlinux-50c8770a.xz kernel image: https://storage.googleapis.com/syzbot-assets/3b397342a62b/bzImage-50c8770a.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+6d7771315ecb9233f395@xxxxxxxxxxxxxxxxxxxxxxxxx ============================================ WARNING: possible recursive locking detected 6.16.0-rc4-next-20250702-syzkaller #0 Not tainted -------------------------------------------- syz-executor365/5837 is trying to acquire lock: ffff8880792cc650 (&sb->s_type->i_mutex_key#15){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:869 [inline] ffff8880792cc650 (&sb->s_type->i_mutex_key#15){+.+.}-{4:4}, at: __simple_recursive_removal+0x95/0x510 fs/libfs.c:614 but task is already holding lock: ffff888027bf0148 (&sb->s_type->i_mutex_key#15){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:869 [inline] ffff888027bf0148 (&sb->s_type->i_mutex_key#15){+.+.}-{4:4}, at: bm_entry_write+0x289/0x540 fs/binfmt_misc.c:737 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&sb->s_type->i_mutex_key#15); lock(&sb->s_type->i_mutex_key#15); *** DEADLOCK *** May be due to missing lock nesting notation 2 locks held by syz-executor365/5837: #0: ffff88807e5fc428 (sb_writers#8){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3098 [inline] #0: ffff88807e5fc428 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x211/0xa90 fs/read_write.c:682 #1: ffff888027bf0148 (&sb->s_type->i_mutex_key#15){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:869 [inline] #1: ffff888027bf0148 (&sb->s_type->i_mutex_key#15){+.+.}-{4:4}, at: bm_entry_write+0x289/0x540 fs/binfmt_misc.c:737 stack backtrace: CPU: 0 UID: 0 PID: 5837 Comm: syz-executor365 Not tainted 6.16.0-rc4-next-20250702-syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Call Trace: <TASK> dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 print_deadlock_bug+0x28b/0x2a0 kernel/locking/lockdep.c:3044 check_deadlock kernel/locking/lockdep.c:3096 [inline] validate_chain+0x1a3f/0x2140 kernel/locking/lockdep.c:3898 __lock_acquire+0xab9/0xd20 kernel/locking/lockdep.c:5240 lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5871 down_write+0x96/0x1f0 kernel/locking/rwsem.c:1577 inode_lock include/linux/fs.h:869 [inline] __simple_recursive_removal+0x95/0x510 fs/libfs.c:614 remove_binfmt_handler fs/binfmt_misc.c:694 [inline] bm_entry_write+0x4f7/0x540 fs/binfmt_misc.c:749 vfs_write+0x27e/0xa90 fs/read_write.c:684 ksys_write+0x145/0x250 fs/read_write.c:738 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f147e7aa369 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffed0db9fa8 EFLAGS: 00000246 ORIG_RAX --- 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. If the report is already addressed, let syzbot know by replying with: #syz fix: exact-commit-title 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. If you want to overwrite report's subsystems, reply with: #syz set subsystems: new-subsystem (See the list of subsystem names on the web dashboard) If the report is a duplicate of another one, reply with: #syz dup: exact-subject-of-another-report If you want to undo deduplication, reply with: #syz undup
