Hello, syzbot found the following issue on: HEAD commit: 99a648c951ba selftests/bpf: Verify that sync_linked_regs p.. git tree: bpf console output: https://syzkaller.appspot.com/x/log.txt?x=1668bd07980000 kernel config: https://syzkaller.appspot.com/x/.config?x=d3e39725ec0dfcbc dashboard link: https://syzkaller.appspot.com/bug?extid=5a878c984150fad34185 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/e45f24c2d262/disk-99a648c9.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/48ad218fc65c/vmlinux-99a648c9.xz kernel image: https://storage.googleapis.com/syzbot-assets/691b40913107/bzImage-99a648c9.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+5a878c984150fad34185@xxxxxxxxxxxxxxxxxxxxxxxxx tun0: tun_chr_ioctl cmd 1074025681 ====================================================== WARNING: possible circular locking dependency detected 6.11.0-syzkaller-10550-g99a648c951ba #0 Not tainted ------------------------------------------------------ syz.0.924/9009 is trying to acquire lock: ffff8881404006d8 (&n->list_lock){-.-.}-{2:2}, at: __put_partials+0x61/0x130 mm/slub.c:3126 but task is already holding lock: ffff8880758dda00 (&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:5822 __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 0xffffffffa00021b3 bpf_dispatcher_nop_func include/linux/bpf.h:1257 [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:2318 [inline] bpf_trace_run2+0x2ec/0x540 kernel/trace/bpf_trace.c:2359 trace_contention_end+0x114/0x140 include/trace/events/lock.h:122 __pv_queued_spin_lock_slowpath+0xb7e/0xdb0 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:3126 put_cpu_partial+0x17c/0x250 mm/slub.c:3221 __slab_free+0x2ea/0x3d0 mm/slub.c:4450 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x9a/0x140 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x14f/0x170 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x23/0x80 mm/kasan/common.c:329 kasan_slab_alloc include/linux/kasan.h:247 [inline] slab_post_alloc_hook mm/slub.c:4086 [inline] slab_alloc_node mm/slub.c:4135 [inline] kmem_cache_alloc_node_noprof+0x16b/0x320 mm/slub.c:4187 perf_event_alloc+0x166/0x2310 kernel/events/core.c:12147 __do_sys_perf_event_open kernel/events/core.c:12767 [inline] __se_sys_perf_event_open+0xb1f/0x3870 kernel/events/core.c:12658 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 -> #0 (&n->list_lock){-.-.}-{2:2}: check_prev_add kernel/locking/lockdep.c:3158 [inline] check_prevs_add kernel/locking/lockdep.c:3277 [inline] validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3901 __lock_acquire+0x1384/0x2050 kernel/locking/lockdep.c:5199 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5822 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd5/0x120 kernel/locking/spinlock.c:162 __put_partials+0x61/0x130 mm/slub.c:3126 ___slab_alloc+0x4f7/0x14b0 mm/slub.c:3776 __slab_alloc+0x58/0xa0 mm/slub.c:3909 __slab_alloc_node mm/slub.c:3962 [inline] slab_alloc_node mm/slub.c:4123 [inline] __do_kmalloc_node mm/slub.c:4264 [inline] __kmalloc_node_noprof+0x286/0x440 mm/slub.c:4271 kmalloc_array_node_noprof include/linux/slab.h:995 [inline] alloc_slab_obj_exts mm/slub.c:1969 [inline] account_slab mm/slub.c:2542 [inline] allocate_slab+0xb6/0x2f0 mm/slub.c:2597 new_slab mm/slub.c:2632 [inline] ___slab_alloc+0xcd1/0x14b0 mm/slub.c:3819 __slab_alloc+0x58/0xa0 mm/slub.c:3909 __slab_alloc_node mm/slub.c:3962 [inline] slab_alloc_node mm/slub.c:4123 [inline] __do_kmalloc_node mm/slub.c:4264 [inline] __kmalloc_node_noprof+0x286/0x440 mm/slub.c:4271 kmalloc_node_noprof include/linux/slab.h:905 [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:1849 bpf_map_do_batch+0x39a/0x660 kernel/bpf/syscall.c:5143 __sys_bpf+0x377/0x810 __do_sys_bpf kernel/bpf/syscall.c:5741 [inline] __se_sys_bpf kernel/bpf/syscall.c:5739 [inline] __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:5739 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 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.0.924/9009: #0: ffffffff8e937ee0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #0: ffffffff8e937ee0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8e937ee0 (rcu_read_lock){....}-{1:2}, at: bpf_map_update_value+0x3c4/0x540 kernel/bpf/syscall.c:202 #1: ffff8880758dda00 (&trie->lock){-.-.}-{2:2}, at: trie_update_elem+0xc8/0xc00 kernel/bpf/lpm_trie.c:333 stack backtrace: CPU: 0 UID: 0 PID: 9009 Comm: syz.0.924 Not tainted 6.11.0-syzkaller-10550-g99a648c951ba #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_circular_bug+0x13a/0x1b0 kernel/locking/lockdep.c:2074 check_noncircular+0x36a/0x4a0 kernel/locking/lockdep.c:2203 check_prev_add kernel/locking/lockdep.c:3158 [inline] check_prevs_add kernel/locking/lockdep.c:3277 [inline] validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3901 __lock_acquire+0x1384/0x2050 kernel/locking/lockdep.c:5199 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5822 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd5/0x120 kernel/locking/spinlock.c:162 __put_partials+0x61/0x130 mm/slub.c:3126 ___slab_alloc+0x4f7/0x14b0 mm/slub.c:3776 __slab_alloc+0x58/0xa0 mm/slub.c:3909 __slab_alloc_node mm/slub.c:3962 [inline] slab_alloc_node mm/slub.c:4123 [inline] __do_kmalloc_node mm/slub.c:4264 [inline] __kmalloc_node_noprof+0x286/0x440 mm/slub.c:4271 kmalloc_array_node_noprof include/linux/slab.h:995 [inline] alloc_slab_obj_exts mm/slub.c:1969 [inline] account_slab mm/slub.c:2542 [inline] allocate_slab+0xb6/0x2f0 mm/slub.c:2597 new_slab mm/slub.c:2632 [inline] ___slab_alloc+0xcd1/0x14b0 mm/slub.c:3819 __slab_alloc+0x58/0xa0 mm/slub.c:3909 __slab_alloc_node mm/slub.c:3962 [inline] slab_alloc_node mm/slub.c:4123 [inline] __do_kmalloc_node mm/slub.c:4264 [inline] __kmalloc_node_noprof+0x286/0x440 mm/slub.c:4271 kmalloc_node_noprof include/linux/slab.h:905 [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:1849 bpf_map_do_batch+0x39a/0x660 kernel/bpf/syscall.c:5143 __sys_bpf+0x377/0x810 __do_sys_bpf kernel/bpf/syscall.c:5741 [inline] __se_sys_bpf kernel/bpf/syscall.c:5739 [inline] __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:5739 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: 0033:0x7fea6a97dff9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fea6b756038 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 00007fea6ab35f80 RCX: 00007fea6a97dff9 RDX: 0000000000000038 RSI: 0000000020000480 RDI: 000000000000001a RBP: 00007fea6a9f0296 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fea6ab35f80 R15: 00007ffd21039768 </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 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
