Message-ID: <67251dc6.050a0220.529b6.015e.GAE@google.com>
Date: Fri, 01 Nov 2024 11:28:22 -0700
From: syzbot <syzbot+6ea37e2e6ffccf41a7e6@...kaller.appspotmail.com>
To: gregkh@...uxfoundation.org, linux-kernel@...r.kernel.org, 
	syzkaller-bugs@...glegroups.com, tj@...nel.org
Subject: [syzbot] [kernfs?] WARNING: locking bug in kernfs_path_from_node

Hello,

syzbot found the following issue on:

HEAD commit:    f9f24ca362a4 Add linux-next specific files for 20241031
git tree:       linux-next
console+strace: https://syzkaller.appspot.com/x/log.txt?x=17a0a187980000
kernel config:  https://syzkaller.appspot.com/x/.config?x=328572ed4d152be9
dashboard link: https://syzkaller.appspot.com/bug?extid=6ea37e2e6ffccf41a7e6
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=13119340580000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=14d56630580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/eb84549dd6b3/disk-f9f24ca3.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/beb29bdfa297/vmlinux-f9f24ca3.xz
kernel image: https://storage.googleapis.com/syzbot-assets/8881fe3245ad/bzImage-f9f24ca3.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+6ea37e2e6ffccf41a7e6@...kaller.appspotmail.com

=============================
[ BUG: Invalid wait context ]
6.12.0-rc5-next-20241031-syzkaller #0 Not tainted
-----------------------------
strace-static-x/5846 is trying to lock:
ffffffff8eac8698 (kernfs_rename_lock){....}-{3:3}, at: kernfs_path_from_node+0x92/0xb00 fs/kernfs/dir.c:229
other info that might help us debug this:
context-{5:5}
3 locks held by strace-static-x/5846:
 #0: ffff8880b873e598 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:598
 #1: ffffffff8e939f20 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline]
 #1: ffffffff8e939f20 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #1: ffffffff8e939f20 (rcu_read_lock){....}-{1:3}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2339 [inline]
 #1: ffffffff8e939f20 (rcu_read_lock){....}-{1:3}, at: bpf_trace_run2+0x1fc/0x540 kernel/trace/bpf_trace.c:2381
 #2: ffff88802f7129e0 (&mm->mmap_lock){++++}-{4:4}, at: mmap_read_trylock include/linux/mmap_lock.h:208 [inline]
 #2: ffff88802f7129e0 (&mm->mmap_lock){++++}-{4:4}, at: stack_map_get_build_id_offset+0x431/0x870 kernel/bpf/stackmap.c:157
stack backtrace:
CPU: 1 UID: 0 PID: 5846 Comm: strace-static-x Not tainted 6.12.0-rc5-next-20241031-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
 print_lock_invalid_wait_context kernel/locking/lockdep.c:4826 [inline]
 check_wait_context kernel/locking/lockdep.c:4898 [inline]
 __lock_acquire+0x15a8/0x2100 kernel/locking/lockdep.c:5176
 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849
 __raw_read_lock_irqsave include/linux/rwlock_api_smp.h:160 [inline]
 _raw_read_lock_irqsave+0xdd/0x130 kernel/locking/spinlock.c:236
 kernfs_path_from_node+0x92/0xb00 fs/kernfs/dir.c:229
 kernfs_path include/linux/kernfs.h:598 [inline]
 cgroup_path include/linux/cgroup.h:599 [inline]
 get_mm_memcg_path+0xb9/0x380 mm/mmap_lock.c:82
 __mmap_lock_do_trace_acquire_returned+0x9f/0x2f0 mm/mmap_lock.c:102
 __mmap_lock_trace_acquire_returned include/linux/mmap_lock.h:36 [inline]
 mmap_read_trylock include/linux/mmap_lock.h:209 [inline]
 stack_map_get_build_id_offset+0x84d/0x870 kernel/bpf/stackmap.c:157
 __bpf_get_stack+0x8da/0xad0 kernel/bpf/stackmap.c:483
 ____bpf_get_stack kernel/bpf/stackmap.c:499 [inline]
 bpf_get_stack+0x33/0x50 kernel/bpf/stackmap.c:496
 ____bpf_get_stack_raw_tp kernel/trace/bpf_trace.c:1933 [inline]
 bpf_get_stack_raw_tp+0x1a3/0x240 kernel/trace/bpf_trace.c:1923
 bpf_prog_ec3b2eefa702d8d3+0x43/0x47
 bpf_dispatcher_nop_func include/linux/bpf.h:1290 [inline]
 __bpf_prog_run include/linux/filter.h:701 [inline]
 bpf_prog_run include/linux/filter.h:708 [inline]
 __bpf_trace_run kernel/trace/bpf_trace.c:2340 [inline]
 bpf_trace_run2+0x2ec/0x540 kernel/trace/bpf_trace.c:2381
 trace_tlb_flush+0x118/0x140 include/trace/events/tlb.h:38
 switch_mm_irqs_off+0x77a/0xa70
 context_switch kernel/sched/core.c:5311 [inline]
 __schedule+0x10c7/0x4c30 kernel/sched/core.c:6707
 __schedule_loop kernel/sched/core.c:6784 [inline]
 schedule+0x14b/0x320 kernel/sched/core.c:6799
 do_wait+0x2a5/0x560 kernel/exit.c:1696
 kernel_wait4+0x2a7/0x3e0 kernel/exit.c:1850
 __do_sys_wait4 kernel/exit.c:1878 [inline]
 __se_sys_wait4 kernel/exit.c:1874 [inline]
 __x64_sys_wait4+0x134/0x1e0 kernel/exit.c:1874
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x4d6ad6
Code: Unable to access opcode bytes at 0x4d6aac.
RSP: 002b:00007ffc879cddd8 EFLAGS: 00000246 ORIG_RAX: 000000000000003d
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00000000004d6ad6
RDX: 0000000040000000 RSI: 00007ffc879cddfc RDI: 00000000ffffffff
RBP: 0000000000000000 R08: 0000000000000017 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000001b15d400
R13: 00007ffc879cddfc R14: 000000001b157ce0 R15: 000000000063f160
 </TASK>


---
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