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=17c4d3d4580000 kernel config: https://syzkaller.appspot.com/x/.config?x=70c16e4e191115d4 dashboard link: https://syzkaller.appspot.com/bug?extid=268eaa983b2fb27e5e38 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=15403770580000 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+268eaa983b2fb27e5e38@xxxxxxxxxxxxxxxxxxxxxxxxx ============================= WARNING: suspicious RCU usage 6.16.0-rc4-next-20250702-syzkaller #0 Not tainted ----------------------------- fs/proc/proc_sysctl.c:934 suspicious rcu_dereference_check() usage! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 2 locks held by syz-executor/5897: #0: ffff888074b98190 (&sb->s_type->i_mutex_key#10){++++}-{4:4}, at: inode_lock_shared include/linux/fs.h:884 [inline] #0: ffff888074b98190 (&sb->s_type->i_mutex_key#10){++++}-{4:4}, at: lookup_slow+0x46/0x70 fs/namei.c:1824 #1: ffff88803150c0d0 (&lockref->lock){+.+.}-{3:3}, at: spin_lock include/linux/spinlock.h:351 [inline] #1: ffff88803150c0d0 (&lockref->lock){+.+.}-{3:3}, at: d_wait_lookup fs/dcache.c:2537 [inline] #1: ffff88803150c0d0 (&lockref->lock){+.+.}-{3:3}, at: d_alloc_parallel+0xbe4/0x15e0 fs/dcache.c:2624 stack backtrace: CPU: 0 UID: 0 PID: 5897 Comm: syz-executor 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 lockdep_rcu_suspicious+0x140/0x1d0 kernel/locking/lockdep.c:6871 proc_sys_compare+0x27d/0x2c0 fs/proc/proc_sysctl.c:934 d_same_name fs/dcache.c:2179 [inline] d_alloc_parallel+0x1060/0x15e0 fs/dcache.c:2637 __lookup_slow+0x116/0x3d0 fs/namei.c:1793 lookup_slow+0x53/0x70 fs/namei.c:1825 walk_component fs/namei.c:2129 [inline] link_path_walk+0x935/0xea0 fs/namei.c:2497 path_openat+0x28c/0x3830 fs/namei.c:4042 do_filp_open+0x1fa/0x410 fs/namei.c:4073 do_sys_openat2+0x121/0x1c0 fs/open.c:1434 do_sys_open fs/open.c:1449 [inline] __do_sys_openat fs/open.c:1465 [inline] __se_sys_openat fs/open.c:1460 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1460 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: 0033:0x7f0fb218d211 Code: 75 57 89 f0 25 00 00 41 00 3d 00 00 41 00 74 49 80 3d 3a 83 1f 00 00 74 6d 89 da 48 89 ee bf 9c ff ff ff b8 01 01 00 00 0f 05 <48> 3d 00 f0 ff ff 0f 87 93 00 00 00 48 8b 54 24 28 64 48 2b 14 25 RSP: 002b:00007ffcf4d54bd0 EFLAGS: 00000202 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 0000000000080001 RCX: 00007f0fb218d211 RDX: 0000000000080001 RSI: 00007f0fb21eeb68 RDI: 00000000ffffff9c RBP: 00007f0fb21eeb68 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000007 R13: 00007ffcf4d54c70 R14: 0000000000000009 R15: 0000000000000000 </TASK> --- 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
