[syzbot] [bpf?] possible deadlock in get_page_from_freelist

syzbot
2024-04-15T02:28:17Z

Hello,

syzbot found the following issue on:

HEAD commit: 7efd0a74039f Merge tag 'ata-6.9-rc4' of git://git.kernel.o..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1358aeed180000
kernel config: https://syzkaller.appspot.com/x/.config?x=285be8dd6baeb438
dashboard link: https://syzkaller.appspot.com/bug?extid=a7f061d2d16154538c58
compiler: gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40

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

Downloadable assets:
disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/7bc7510fe41f/non_bootable_disk-7efd0a74.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/39eb4e17e7f0/vmlinux-7efd0a74.xz
kernel image: https://storage.googleapis.com/syzbot-assets/b9a08c36e0ca/bzImage-7efd0a74.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+a7f061d2d16154538c58@syzkaller.appspotmail.com

======================================================
WARNING: possible circular locking dependency detected
6.9.0-rc3-syzkaller-00355-g7efd0a74039f #0 Not tainted
------------------------------------------------------
syz-executor.2/7645 is trying to acquire lock:
ffff88807ffd7d58 (&zone->lock){-.-.}-{2:2}, at: rmqueue_buddy mm/page_alloc.c:2730 [inline]
ffff88807ffd7d58 (&zone->lock){-.-.}-{2:2}, at: rmqueue mm/page_alloc.c:2911 [inline]
ffff88807ffd7d58 (&zone->lock){-.-.}-{2:2}, at: get_page_from_freelist+0x4b9/0x3780 mm/page_alloc.c:3314

but task is already holding lock:
ffff88802c8739f8 (&trie->lock){-.-.}-{2:2}, at: trie_update_elem+0xc8/0xdd0 kernel/bpf/lpm_trie.c:324

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> #1 (&trie->lock){-.-.}-{2:2}:
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
_raw_spin_lock_irqsave+0x3a/0x60 kernel/locking/spinlock.c:162
trie_delete_elem+0xb0/0x7e0 kernel/bpf/lpm_trie.c:451
___bpf_prog_run+0x3e51/0xabd0 kernel/bpf/core.c:1997
__bpf_prog_run32+0xc1/0x100 kernel/bpf/core.c:2236
bpf_dispatcher_nop_func include/linux/bpf.h:1234 [inline]
__bpf_prog_run include/linux/filter.h:657 [inline]
bpf_prog_run include/linux/filter.h:664 [inline]
__bpf_trace_run kernel/trace/bpf_trace.c:2381 [inline]
bpf_trace_run2+0x151/0x420 kernel/trace/bpf_trace.c:2420
__bpf_trace_contention_end+0xca/0x110 include/trace/events/lock.h:122
trace_contention_end.constprop.0+0xea/0x170 include/trace/events/lock.h:122
__pv_queued_spin_lock_slowpath+0x266/0xc80 kernel/locking/qspinlock.c:560
pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:584 [inline]
queued_spin_lock_slowpath arch/x86/include/asm/qspinlock.h:51 [inline]
queued_spin_lock include/asm-generic/qspinlock.h:114 [inline]
do_raw_spin_lock+0x210/0x2c0 kernel/locking/spinlock_debug.c:116
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:111 [inline]
_raw_spin_lock_irqsave+0x42/0x60 kernel/locking/spinlock.c:162
rmqueue_bulk mm/page_alloc.c:2131 [inline]
__rmqueue_pcplist+0x5a8/0x1b00 mm/page_alloc.c:2826
rmqueue_pcplist mm/page_alloc.c:2868 [inline]
rmqueue mm/page_alloc.c:2905 [inline]
get_page_from_freelist+0xbaa/0x3780 mm/page_alloc.c:3314
__alloc_pages+0x22b/0x2460 mm/page_alloc.c:4575
__alloc_pages_node include/linux/gfp.h:238 [inline]
alloc_pages_node include/linux/gfp.h:261 [inline]
alloc_slab_page mm/slub.c:2175 [inline]
allocate_slab mm/slub.c:2338 [inline]
new_slab+0xcc/0x3a0 mm/slub.c:2391
___slab_alloc+0x66d/0x1790 mm/slub.c:3525
__slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3610
__slab_alloc_node mm/slub.c:3663 [inline]
slab_alloc_node mm/slub.c:3835 [inline]
__do_kmalloc_node mm/slub.c:3965 [inline]
__kmalloc_node_track_caller+0x367/0x470 mm/slub.c:3986
kmalloc_reserve+0xef/0x2c0 net/core/skbuff.c:599
__alloc_skb+0x164/0x380 net/core/skbuff.c:668
alloc_skb include/linux/skbuff.h:1313 [inline]
nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:748 [inline]
nsim_dev_trap_report drivers/net/netdevsim/dev.c:805 [inline]
nsim_dev_trap_report_work+0x2a4/0xc80 drivers/net/netdevsim/dev.c:850
process_one_work+0x9a9/0x1ac0 kernel/workqueue.c:3254
process_scheduled_works kernel/workqueue.c:3335 [inline]
worker_thread+0x6c8/0xf70 kernel/workqueue.c:3416
kthread+0x2c1/0x3a0 kernel/kthread.c:388
ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

-> #0 (&zone->lock){-.-.}-{2:2}:
check_prev_add kernel/locking/lockdep.c:3134 [inline]
check_prevs_add kernel/locking/lockdep.c:3253 [inline]
validate_chain kernel/locking/lockdep.c:3869 [inline]
__lock_acquire+0x2478/0x3b30 kernel/locking/lockdep.c:5137
lock_acquire kernel/locking/lockdep.c:5754 [inline]
lock_acquire+0x1b1/0x560 kernel/locking/lockdep.c:5719
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
_raw_spin_lock_irqsave+0x3a/0x60 kernel/locking/spinlock.c:162
rmqueue_buddy mm/page_alloc.c:2730 [inline]
rmqueue mm/page_alloc.c:2911 [inline]
get_page_from_freelist+0x4b9/0x3780 mm/page_alloc.c:3314
__alloc_pages+0x22b/0x2460 mm/page_alloc.c:4575
__alloc_pages_node include/linux/gfp.h:238 [inline]
alloc_pages_node include/linux/gfp.h:261 [inline]
__kmalloc_large_node+0x7f/0x1a0 mm/slub.c:3911
__do_kmalloc_node mm/slub.c:3954 [inline]
__kmalloc_node.cold+0x5/0x5f mm/slub.c:3973
kmalloc_node include/linux/slab.h:648 [inline]
bpf_map_kmalloc_node+0x98/0x4a0 kernel/bpf/syscall.c:422
lpm_trie_node_alloc kernel/bpf/lpm_trie.c:291 [inline]
trie_update_elem+0x1ef/0xdd0 kernel/bpf/lpm_trie.c:333
bpf_map_update_value+0x2c1/0x6c0 kernel/bpf/syscall.c:203
map_update_elem+0x623/0x910 kernel/bpf/syscall.c:1641
__sys_bpf+0xab9/0x4b40 kernel/bpf/syscall.c:5648
__do_sys_bpf kernel/bpf/syscall.c:5767 [inline]
__se_sys_bpf kernel/bpf/syscall.c:5765 [inline]
__x64_sys_bpf+0x78/0xc0 kernel/bpf/syscall.c:5765
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xcf/0x260 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(&zone->lock);
lock(&trie->lock);
lock(&zone->lock);

*** DEADLOCK ***

2 locks held by syz-executor.2/7645:
#0: ffffffff8d7b0e20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline]
#0: ffffffff8d7b0e20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline]
#0: ffffffff8d7b0e20 (rcu_read_lock){....}-{1:2}, at: bpf_map_update_value+0x24b/0x6c0 kernel/bpf/syscall.c:202
#1: ffff88802c8739f8 (&trie->lock){-.-.}-{2:2}, at: trie_update_elem+0xc8/0xdd0 kernel/bpf/lpm_trie.c:324

stack backtrace:
CPU: 1 PID: 7645 Comm: syz-executor.2 Not tainted 6.9.0-rc3-syzkaller-00355-g7efd0a74039f #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:114
check_noncircular+0x31a/0x400 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 kernel/locking/lockdep.c:3869 [inline]
__lock_acquire+0x2478/0x3b30 kernel/locking/lockdep.c:5137
lock_acquire kernel/locking/lockdep.c:5754 [inline]
lock_acquire+0x1b1/0x560 kernel/locking/lockdep.c:5719
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
_raw_spin_lock_irqsave+0x3a/0x60 kernel/locking/spinlock.c:162
rmqueue_buddy mm/page_alloc.c:2730 [inline]
rmqueue mm/page_alloc.c:2911 [inline]
get_page_from_freelist+0x4b9/0x3780 mm/page_alloc.c:3314
__alloc_pages+0x22b/0x2460 mm/page_alloc.c:4575
__alloc_pages_node include/linux/gfp.h:238 [inline]
alloc_pages_node include/linux/gfp.h:261 [inline]
__kmalloc_large_node+0x7f/0x1a0 mm/slub.c:3911
__do_kmalloc_node mm/slub.c:3954 [inline]
__kmalloc_node.cold+0x5/0x5f mm/slub.c:3973
kmalloc_node include/linux/slab.h:648 [inline]
bpf_map_kmalloc_node+0x98/0x4a0 kernel/bpf/syscall.c:422
lpm_trie_node_alloc kernel/bpf/lpm_trie.c:291 [inline]
trie_update_elem+0x1ef/0xdd0 kernel/bpf/lpm_trie.c:333
bpf_map_update_value+0x2c1/0x6c0 kernel/bpf/syscall.c:203
map_update_elem+0x623/0x910 kernel/bpf/syscall.c:1641
__sys_bpf+0xab9/0x4b40 kernel/bpf/syscall.c:5648
__do_sys_bpf kernel/bpf/syscall.c:5767 [inline]
__se_sys_bpf kernel/bpf/syscall.c:5765 [inline]
__x64_sys_bpf+0x78/0xc0 kernel/bpf/syscall.c:5765
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xcf/0x260 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fdb1c27de69
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:00007fdb1d0210c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000141
RAX: ffffffffffffffda RBX: 00007fdb1c3abf80 RCX: 00007fdb1c27de69
RDX: 0000000000000020 RSI: 0000000020001400 RDI: 0000000000000002
RBP: 00007fdb1c2ca47a R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007fdb1c3abf80 R15: 00007ffe7cd30f08
</TASK>
loop2: detected capacity change from 0 to 512
ext4: Unknown parameter '���������������3;�{\C _r���f�gD\x19Z*��ג�Md�;�s�8)V^[�Z�-#��S%\x19�SY�E`1t\x10AS�>�>���\x0ed]�x��h'

---
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