Hello, syzbot found the following issue on: HEAD commit: 3d650ab5e7d9 selftests/bpf: Fix a btf_dump selftest failure git tree: bpf-next console+strace: https://syzkaller.appspot.com/x/log.txt?x=1628e483980000 kernel config: https://syzkaller.appspot.com/x/.config?x=5efb917b1462a973 dashboard link: https://syzkaller.appspot.com/bug?extid=ee7551b0640c5471e610 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=117de4e5980000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=142e86bd980000 Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/630e210de8d9/disk-3d650ab5.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/3576ca35748a/vmlinux-3d650ab5.xz kernel image: https://storage.googleapis.com/syzbot-assets/5b33f099abfa/bzImage-3d650ab5.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+ee7551b0640c5471e610@xxxxxxxxxxxxxxxxxxxxxxxxx ====================================================== WARNING: possible circular locking dependency detected 6.10.0-syzkaller-12666-g3d650ab5e7d9 #0 Not tainted ------------------------------------------------------ strace-static-x/5224 is trying to acquire lock: ffff888024c4e218 (&htab->lockdep_key){....}-{2:2}, at: htab_lock_bucket+0x1a4/0x370 kernel/bpf/hashtab.c:167 but task is already holding lock: ffff888023c33188 (&htab->lockdep_key#3){....}-{2:2}, at: htab_lock_bucket+0x1a4/0x370 kernel/bpf/hashtab.c:167 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&htab->lockdep_key#3){....}-{2:2}: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5759 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline] _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154 htab_lock_bucket+0x1a4/0x370 kernel/bpf/hashtab.c:167 htab_lru_map_delete_elem+0x1f1/0x700 kernel/bpf/hashtab.c:1462 bpf_prog_6f5f05285f674219+0x43/0x4c bpf_dispatcher_nop_func include/linux/bpf.h:1252 [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:2406 [inline] bpf_trace_run2+0x2ec/0x540 kernel/trace/bpf_trace.c:2447 __traceiter_contention_begin+0x7b/0xb0 include/trace/events/lock.h:95 trace_contention_begin+0x117/0x140 include/trace/events/lock.h:95 __pv_queued_spin_lock_slowpath+0x114/0xdc0 kernel/locking/qspinlock.c:402 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 htab_lock_bucket+0x1a4/0x370 kernel/bpf/hashtab.c:167 htab_lru_map_delete_elem+0x1f1/0x700 kernel/bpf/hashtab.c:1462 0xffffffffa000204b bpf_dispatcher_nop_func include/linux/bpf.h:1252 [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:2406 [inline] bpf_trace_run2+0x2ec/0x540 kernel/trace/bpf_trace.c:2447 __traceiter_contention_begin+0x7b/0xb0 include/trace/events/lock.h:95 trace_contention_begin+0xf5/0x120 include/trace/events/lock.h:95 __mutex_lock_common kernel/locking/mutex.c:610 [inline] __mutex_lock+0x147/0xd70 kernel/locking/mutex.c:752 pipe_read+0x12a/0x13e0 fs/pipe.c:264 new_sync_read fs/read_write.c:395 [inline] vfs_read+0x9bd/0xbc0 fs/read_write.c:476 ksys_read+0x1a0/0x2c0 fs/read_write.c:619 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 (&htab->lockdep_key){....}-{2:2}: check_prev_add kernel/locking/lockdep.c:3133 [inline] check_prevs_add kernel/locking/lockdep.c:3252 [inline] validate_chain+0x18e0/0x5900 kernel/locking/lockdep.c:3868 __lock_acquire+0x137a/0x2040 kernel/locking/lockdep.c:5142 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5759 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline] _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154 htab_lock_bucket+0x1a4/0x370 kernel/bpf/hashtab.c:167 htab_lru_map_delete_elem+0x1f1/0x700 kernel/bpf/hashtab.c:1462 0xffffffffa000204b bpf_dispatcher_nop_func include/linux/bpf.h:1252 [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:2406 [inline] bpf_trace_run2+0x2ec/0x540 kernel/trace/bpf_trace.c:2447 __traceiter_contention_begin+0x7b/0xb0 include/trace/events/lock.h:95 trace_contention_begin+0x117/0x140 include/trace/events/lock.h:95 __pv_queued_spin_lock_slowpath+0x114/0xdc0 kernel/locking/qspinlock.c:402 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 htab_lock_bucket+0x1a4/0x370 kernel/bpf/hashtab.c:167 htab_lru_map_delete_elem+0x1f1/0x700 kernel/bpf/hashtab.c:1462 bpf_prog_6f5f05285f674219+0x43/0x4c bpf_dispatcher_nop_func include/linux/bpf.h:1252 [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:2406 [inline] bpf_trace_run2+0x2ec/0x540 kernel/trace/bpf_trace.c:2447 __traceiter_contention_begin+0x7b/0xb0 include/trace/events/lock.h:95 trace_contention_begin+0xf5/0x120 include/trace/events/lock.h:95 __mutex_lock_common kernel/locking/mutex.c:610 [inline] __mutex_lock+0x147/0xd70 kernel/locking/mutex.c:752 pipe_write+0x1c9/0x1a40 fs/pipe.c:455 new_sync_write fs/read_write.c:497 [inline] vfs_write+0xa72/0xc90 fs/read_write.c:590 ksys_write+0x1a0/0x2c0 fs/read_write.c:643 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(&htab->lockdep_key#3); lock(&htab->lockdep_key); lock(&htab->lockdep_key#3); lock(&htab->lockdep_key); *** DEADLOCK *** 4 locks held by strace-static-x/5224: #0: ffff88802c11bc68 (&pipe->mutex){+.+.}-{3:3}, at: pipe_write+0x1c9/0x1a40 fs/pipe.c:455 #1: ffffffff8e937660 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:326 [inline] #1: ffffffff8e937660 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #1: ffffffff8e937660 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2405 [inline] #1: ffffffff8e937660 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run2+0x1fc/0x540 kernel/trace/bpf_trace.c:2447 #2: ffff888023c33188 (&htab->lockdep_key#3){....}-{2:2}, at: htab_lock_bucket+0x1a4/0x370 kernel/bpf/hashtab.c:167 #3: ffffffff8e937660 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:326 [inline] #3: ffffffff8e937660 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #3: ffffffff8e937660 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2405 [inline] #3: ffffffff8e937660 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run2+0x1fc/0x540 kernel/trace/bpf_trace.c:2447 stack backtrace: CPU: 0 UID: 0 PID: 5224 Comm: strace-static-x Not tainted 6.10.0-syzkaller-12666-g3d650ab5e7d9 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024 Call Trace: <TASK> __dump_stack lib/dump_stack.c:93 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:119 check_noncircular+0x36a/0x4a0 kernel/locking/lockdep.c:2186 check_prev_add kernel/locking/lockdep.c:3133 [inline] check_prevs_add kernel/locking/lockdep.c:3252 [inline] validate_chain+0x18e0/0x5900 kernel/locking/lockdep.c:3868 __lock_acquire+0x137a/0x2040 kernel/locking/lockdep.c:5142 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5759 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline] _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154 htab_lock_bucket+0x1a4/0x370 kernel/bpf/hashtab.c:167 htab_lru_map_delete_elem+0x1f1/0x700 kernel/bpf/hashtab.c:1462 </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
