Message-ID: <0000000000007d6a8c061905fa5a@google.com>
Date: Wed, 22 May 2024 00:35:28 -0700
From: syzbot <syzbot+9045c0a3d5a7f1b119f7@...kaller.appspotmail.com>
To: andrii@...nel.org, ast@...nel.org, bpf@...r.kernel.org, 
	daniel@...earbox.net, eddyz87@...il.com, haoluo@...gle.com, 
	john.fastabend@...il.com, jolsa@...nel.org, kpsingh@...nel.org, 
	linux-kernel@...r.kernel.org, martin.lau@...ux.dev, netdev@...r.kernel.org, 
	sdf@...gle.com, song@...nel.org, syzkaller-bugs@...glegroups.com, 
	yonghong.song@...ux.dev
Subject: [syzbot] [bpf?] possible deadlock in get_partial_node

Hello,

syzbot found the following issue on:

HEAD commit:    4b377b4868ef kprobe/ftrace: fix build error due to bad fun..
git tree:       net-next
console output: https://syzkaller.appspot.com/x/log.txt?x=1295df6c980000
kernel config:  https://syzkaller.appspot.com/x/.config?x=17ffd15f654c98ba
dashboard link: https://syzkaller.appspot.com/bug?extid=9045c0a3d5a7f1b119f7
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/6f4c61bc9252/disk-4b377b48.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/841f1b24d3a1/vmlinux-4b377b48.xz
kernel image: https://storage.googleapis.com/syzbot-assets/017b655dca3d/bzImage-4b377b48.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+9045c0a3d5a7f1b119f7@...kaller.appspotmail.com

======================================================
WARNING: possible circular locking dependency detected
6.9.0-syzkaller-08544-g4b377b4868ef #0 Not tainted
------------------------------------------------------
syz-executor.0/10441 is trying to acquire lock:
ffff88801504e318 (&n->list_lock){-.-.}-{2:2}, at: get_partial_node+0x36/0x280 mm/slub.c:2601

but task is already holding lock:
ffff88802b82c9f8 (&trie->lock){-.-.}-{2:2}, at: trie_update_elem+0xc8/0xc00 kernel/bpf/lpm_trie.c:333

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (&trie->lock){-.-.}-{2:2}:
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754
       __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
       _raw_spin_lock_irqsave+0xd5/0x120 kernel/locking/spinlock.c:162
       trie_delete_elem+0x96/0x6a0 kernel/bpf/lpm_trie.c:462
       0xffffffffa0001fe2
       bpf_dispatcher_nop_func include/linux/bpf.h:1243 [inline]
       __bpf_prog_run include/linux/filter.h:691 [inline]
       bpf_prog_run include/linux/filter.h:698 [inline]
       __bpf_trace_run kernel/trace/bpf_trace.c:2403 [inline]
       bpf_trace_run2+0x2ec/0x540 kernel/trace/bpf_trace.c:2444
       trace_contention_end+0x114/0x140 include/trace/events/lock.h:122
       __pv_queued_spin_lock_slowpath+0xb81/0xdc0 kernel/locking/qspinlock.c:557
       pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:584 [inline]
       queued_spin_lock_slowpath+0x42/0x50 arch/x86/include/asm/qspinlock.h:51
       queued_spin_lock include/asm-generic/qspinlock.h:114 [inline]
       do_raw_spin_lock+0x272/0x370 kernel/locking/spinlock_debug.c:116
       __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:111 [inline]
       _raw_spin_lock_irqsave+0xe1/0x120 kernel/locking/spinlock.c:162
       __put_partials+0x61/0x130 mm/slub.c:2900
       put_cpu_partial+0x17c/0x250 mm/slub.c:2995
       __slab_free+0x2ea/0x3d0 mm/slub.c:4224
       qlink_free mm/kasan/quarantine.c:163 [inline]
       qlist_free_all+0x5e/0xc0 mm/kasan/quarantine.c:179
       kasan_quarantine_reduce+0x14f/0x170 mm/kasan/quarantine.c:286
       __kasan_slab_alloc+0x23/0x80 mm/kasan/common.c:322
       kasan_slab_alloc include/linux/kasan.h:201 [inline]
       slab_post_alloc_hook mm/slub.c:3871 [inline]
       slab_alloc_node mm/slub.c:3918 [inline]
       kmem_cache_alloc_node+0x194/0x390 mm/slub.c:3961
       __alloc_skb+0x1c3/0x440 net/core/skbuff.c:656
       alloc_skb include/linux/skbuff.h:1308 [inline]
       sock_wmalloc+0xab/0x120 net/core/sock.c:2643
       l2tp_ip_sendmsg+0x1b1/0x1670 net/l2tp/l2tp_ip.c:439
       sock_sendmsg_nosec net/socket.c:730 [inline]
       __sock_sendmsg+0x1a6/0x270 net/socket.c:745
       ____sys_sendmsg+0x525/0x7d0 net/socket.c:2584
       ___sys_sendmsg net/socket.c:2638 [inline]
       __sys_sendmmsg+0x3b2/0x740 net/socket.c:2724
       __do_sys_sendmmsg net/socket.c:2753 [inline]
       __se_sys_sendmmsg net/socket.c:2750 [inline]
       __x64_sys_sendmmsg+0xa0/0xb0 net/socket.c:2750
       do_syscall_x64 arch/x86/entry/common.c:52 [inline]
       do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #0 (&n->list_lock){-.-.}-{2:2}:
       check_prev_add kernel/locking/lockdep.c:3134 [inline]
       check_prevs_add kernel/locking/lockdep.c:3253 [inline]
       validate_chain+0x18cb/0x58e0 kernel/locking/lockdep.c:3869
       __lock_acquire+0x1346/0x1fd0 kernel/locking/lockdep.c:5137
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754
       __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
       _raw_spin_lock_irqsave+0xd5/0x120 kernel/locking/spinlock.c:162
       get_partial_node+0x36/0x280 mm/slub.c:2601
       get_partial mm/slub.c:2715 [inline]
       ___slab_alloc+0xa81/0x12e0 mm/slub.c:3572
       __slab_alloc mm/slub.c:3682 [inline]
       __slab_alloc_node mm/slub.c:3735 [inline]
       slab_alloc_node mm/slub.c:3908 [inline]
       __do_kmalloc_node mm/slub.c:4038 [inline]
       __kmalloc_node+0x2db/0x4f0 mm/slub.c:4046
       kmalloc_node include/linux/slab.h:648 [inline]
       bpf_map_kmalloc_node+0xd3/0x1c0 kernel/bpf/syscall.c:422
       lpm_trie_node_alloc kernel/bpf/lpm_trie.c:299 [inline]
       trie_update_elem+0x1cd/0xc00 kernel/bpf/lpm_trie.c:342
       bpf_map_update_value+0x4d3/0x540 kernel/bpf/syscall.c:203
       generic_map_update_batch+0x60d/0x900 kernel/bpf/syscall.c:1889
       bpf_map_do_batch+0x3e0/0x690 kernel/bpf/syscall.c:5196
       __sys_bpf+0x377/0x810
       __do_sys_bpf kernel/bpf/syscall.c:5794 [inline]
       __se_sys_bpf kernel/bpf/syscall.c:5792 [inline]
       __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:5792
       do_syscall_x64 arch/x86/entry/common.c:52 [inline]
       do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

other info that might help us debug this:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&trie->lock);
                               lock(&n->list_lock);
                               lock(&trie->lock);
  lock(&n->list_lock);

 *** DEADLOCK ***

2 locks held by syz-executor.0/10441:
 #0: ffffffff8e333d20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline]
 #0: ffffffff8e333d20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline]
 #0: ffffffff8e333d20 (rcu_read_lock){....}-{1:2}, at: bpf_map_update_value+0x3c4/0x540 kernel/bpf/syscall.c:202
 #1: ffff88802b82c9f8 (&trie->lock){-.-.}-{2:2}, at: trie_update_elem+0xc8/0xc00 kernel/bpf/lpm_trie.c:333

stack backtrace:
CPU: 1 PID: 10441 Comm: syz-executor.0 Not tainted 6.9.0-syzkaller-08544-g4b377b4868ef #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114
 check_noncircular+0x36a/0x4a0 kernel/locking/lockdep.c:2187
 check_prev_add kernel/locking/lockdep.c:3134 [inline]
 check_prevs_add kernel/locking/lockdep.c:3253 [inline]
 validate_chain+0x18cb/0x58e0 kernel/locking/lockdep.c:3869
 __lock_acquire+0x1346/0x1fd0 kernel/locking/lockdep.c:5137
 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
 _raw_spin_lock_irqsave+0xd5/0x120 kernel/locking/spinlock.c:162
 get_partial_node+0x36/0x280 mm/slub.c:2601
 get_partial mm/slub.c:2715 [inline]
 ___slab_alloc+0xa81/0x12e0 mm/slub.c:3572
 __slab_alloc mm/slub.c:3682 [inline]
 __slab_alloc_node mm/slub.c:3735 [inline]
 slab_alloc_node mm/slub.c:3908 [inline]
 __do_kmalloc_node mm/slub.c:4038 [inline]
 __kmalloc_node+0x2db/0x4f0 mm/slub.c:4046
 kmalloc_node include/linux/slab.h:648 [inline]
 bpf_map_kmalloc_node+0xd3/0x1c0 kernel/bpf/syscall.c:422
 lpm_trie_node_alloc kernel/bpf/lpm_trie.c:299 [inline]
 trie_update_elem+0x1cd/0xc00 kernel/bpf/lpm_trie.c:342
 bpf_map_update_value+0x4d3/0x540 kernel/bpf/syscall.c:203
 generic_map_update_batch+0x60d/0x900 kernel/bpf/syscall.c:1889
 bpf_map_do_batch+0x3e0/0x690 kernel/bpf/syscall.c:5196
 __sys_bpf+0x377/0x810
 __do_sys_bpf kernel/bpf/syscall.c:5794 [inline]
 __se_sys_bpf kernel/bpf/syscall.c:5792 [inline]
 __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:5792
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f9c7b07cee9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 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 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f9c7bd5e0c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000141
RAX: ffffffffffffffda RBX: 00007f9c7b1ac050 RCX: 00007f9c7b07cee9
RDX: 0000000000000038 RSI: 0000000020000240 RDI: 000000000000001a
RBP: 00007f9c7b0c949e R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000006e R14: 00007f9c7b1ac050 R15: 00007fffe20416d8
 </TASK>


---
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