Hello, syzbot found the following issue on: HEAD commit: b31c44928842 Merge tag 'linux_kselftest-kunit-fixes-6.11-r.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=121a189f980000 kernel config: https://syzkaller.appspot.com/x/.config?x=57042fe37c7ee7c2 dashboard link: https://syzkaller.appspot.com/bug?extid=26bfd0c1cea0b221a4bf compiler: gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=101c2bc7980000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=11f5ba00580000 Downloadable assets: disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/7bc7510fe41f/non_bootable_disk-b31c4492.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/f518d8293660/vmlinux-b31c4492.xz kernel image: https://storage.googleapis.com/syzbot-assets/d06107105268/bzImage-b31c4492.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+26bfd0c1cea0b221a4bf@xxxxxxxxxxxxxxxxxxxxxxxxx ====================================================== WARNING: possible circular locking dependency detected 6.11.0-rc6-syzkaller-00308-gb31c44928842 #0 Not tainted ------------------------------------------------------ syz-executor169/5356 is trying to acquire lock: ffff888035409940 (&htab->lockdep_key#4){-.-.}-{2:2}, at: htab_lock_bucket kernel/bpf/hashtab.c:167 [inline] ffff888035409940 (&htab->lockdep_key#4){-.-.}-{2:2}, at: htab_map_delete_elem+0x1c8/0x730 kernel/bpf/hashtab.c:1426 but task is already holding lock: ffff888035408820 (&htab->lockdep_key#2){-.-.}-{2:2}, at: htab_lock_bucket kernel/bpf/hashtab.c:167 [inline] ffff888035408820 (&htab->lockdep_key#2){-.-.}-{2:2}, at: htab_map_delete_elem+0x1c8/0x730 kernel/bpf/hashtab.c:1426 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&htab->lockdep_key#2){-.-.}-{2:2}: __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline] _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154 htab_lock_bucket kernel/bpf/hashtab.c:167 [inline] htab_map_delete_elem+0x1c8/0x730 kernel/bpf/hashtab.c:1426 bpf_prog_1a158c95e143a564+0x45/0x4e 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:2406 [inline] bpf_trace_run2+0x231/0x590 kernel/trace/bpf_trace.c:2447 __bpf_trace_contention_end+0xca/0x110 include/trace/events/lock.h:122 __traceiter_contention_end+0x5a/0xa0 include/trace/events/lock.h:122 trace_contention_end.constprop.0+0xea/0x170 include/trace/events/lock.h:122 __pv_queued_spin_lock_slowpath+0x27e/0xc90 kernel/locking/qspinlock.c:557 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 htab_lock_bucket kernel/bpf/hashtab.c:167 [inline] htab_map_delete_elem+0x1c8/0x730 kernel/bpf/hashtab.c:1426 bpf_prog_1a158c95e143a564+0x45/0x4e 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:2406 [inline] bpf_trace_run2+0x231/0x590 kernel/trace/bpf_trace.c:2447 __bpf_trace_contention_end+0xca/0x110 include/trace/events/lock.h:122 __traceiter_contention_end+0x5a/0xa0 include/trace/events/lock.h:122 trace_contention_end+0xce/0x140 include/trace/events/lock.h:122 __mutex_lock_common kernel/locking/mutex.c:617 [inline] __mutex_lock+0x19c/0x9c0 kernel/locking/mutex.c:752 put_rng+0x1a/0xe0 drivers/char/hw_random/core.c:141 rng_dev_read+0x22d/0x720 drivers/char/hw_random/core.c:248 do_loop_readv_writev fs/read_write.c:761 [inline] do_loop_readv_writev fs/read_write.c:749 [inline] vfs_readv+0x6cb/0x8a0 fs/read_write.c:934 do_preadv fs/read_write.c:1049 [inline] __do_sys_preadv fs/read_write.c:1099 [inline] __se_sys_preadv fs/read_write.c:1094 [inline] __x64_sys_preadv+0x22b/0x310 fs/read_write.c:1094 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #0 (&htab->lockdep_key#4){-.-.}-{2:2}: check_prev_add kernel/locking/lockdep.c:3133 [inline] check_prevs_add kernel/locking/lockdep.c:3252 [inline] validate_chain kernel/locking/lockdep.c:3868 [inline] __lock_acquire+0x24ed/0x3cb0 kernel/locking/lockdep.c:5142 lock_acquire kernel/locking/lockdep.c:5759 [inline] lock_acquire+0x1b1/0x560 kernel/locking/lockdep.c:5724 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline] _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154 htab_lock_bucket kernel/bpf/hashtab.c:167 [inline] htab_map_delete_elem+0x1c8/0x730 kernel/bpf/hashtab.c:1426 bpf_prog_1a158c95e143a564+0x45/0x4e 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:2406 [inline] bpf_trace_run2+0x231/0x590 kernel/trace/bpf_trace.c:2447 __bpf_trace_contention_end+0xca/0x110 include/trace/events/lock.h:122 __traceiter_contention_end+0x5a/0xa0 include/trace/events/lock.h:122 trace_contention_end.constprop.0+0xea/0x170 include/trace/events/lock.h:122 __pv_queued_spin_lock_slowpath+0x27e/0xc90 kernel/locking/qspinlock.c:557 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 htab_lock_bucket kernel/bpf/hashtab.c:167 [inline] htab_map_delete_elem+0x1c8/0x730 kernel/bpf/hashtab.c:1426 bpf_prog_1a158c95e143a564+0x45/0x4e 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:2406 [inline] bpf_trace_run2+0x231/0x590 kernel/trace/bpf_trace.c:2447 __bpf_trace_contention_end+0xca/0x110 include/trace/events/lock.h:122 __traceiter_contention_end+0x5a/0xa0 include/trace/events/lock.h:122 trace_contention_end+0xce/0x140 include/trace/events/lock.h:122 __mutex_lock_common kernel/locking/mutex.c:727 [inline] __mutex_lock+0x281/0x9c0 kernel/locking/mutex.c:752 rng_dev_read+0x128/0x720 drivers/char/hw_random/core.c:218 do_loop_readv_writev fs/read_write.c:761 [inline] do_loop_readv_writev fs/read_write.c:749 [inline] vfs_readv+0x6cb/0x8a0 fs/read_write.c:934 do_preadv fs/read_write.c:1049 [inline] __do_sys_preadv fs/read_write.c:1099 [inline] __se_sys_preadv fs/read_write.c:1094 [inline] __x64_sys_preadv+0x22b/0x310 fs/read_write.c:1094 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 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#2); lock(&htab->lockdep_key#4); lock(&htab->lockdep_key#2); lock(&htab->lockdep_key#4); *** DEADLOCK *** 5 locks held by syz-executor169/5356: #0: ffffffff8e9fb728 (reading_mutex){+.+.}-{3:3}, at: rng_dev_read+0x128/0x720 drivers/char/hw_random/core.c:218 #1: ffffffff8e9fb6e0 (reading_mutex.wait_lock){+.+.}-{2:2}, at: __mutex_lock_common kernel/locking/mutex.c:706 [inline] #1: ffffffff8e9fb6e0 (reading_mutex.wait_lock){+.+.}-{2:2}, at: __mutex_lock+0x6ac/0x9c0 kernel/locking/mutex.c:752 #2: ffffffff8ddb9fe0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:326 [inline] #2: ffffffff8ddb9fe0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #2: ffffffff8ddb9fe0 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2405 [inline] #2: ffffffff8ddb9fe0 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run2+0x1c2/0x590 kernel/trace/bpf_trace.c:2447 #3: ffff888035408820 (&htab->lockdep_key#2){-.-.}-{2:2}, at: htab_lock_bucket kernel/bpf/hashtab.c:167 [inline] #3: ffff888035408820 (&htab->lockdep_key#2){-.-.}-{2:2}, at: htab_map_delete_elem+0x1c8/0x730 kernel/bpf/hashtab.c:1426 #4: ffffffff8ddb9fe0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:326 [inline] #4: ffffffff8ddb9fe0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #4: ffffffff8ddb9fe0 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2405 [inline] #4: ffffffff8ddb9fe0 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run2+0x1c2/0x590 kernel/trace/bpf_trace.c:2447 stack backtrace: CPU: 0 UID: 0 PID: 5356 Comm: syz-executor169 Not tainted 6.11.0-rc6-syzkaller-00308-gb31c44928842 #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 Call Trace: <TASK> __dump_stack lib/dump_stack.c:93 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:119 check_noncircular+0x31a/0x400 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 kernel/locking/lockdep.c:3868 [inline] __lock_acquire+0x24ed/0x3cb0 kernel/locking/lockdep.c:5142 lock_acquire kernel/locking/lockdep.c:5759 [inline] lock_acquire+0x1b1/0x560 kernel/locking/lockdep.c:5724 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline] _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154 htab_lock_bucket kernel/bpf/hashtab.c:167 [inline] htab_map_delete_elem+0x1c8/0x730 kernel/bpf/hashtab.c:1426 bpf_prog_1a158c95e143a564+0x45/0x4e 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:2406 [inline] bpf_trace_run2+0x231/0x590 kernel/trace/bpf_trace.c:2447 __bpf_trace_contention_end+0xca/0x110 include/trace/events/lock.h:122 __traceiter_contention_end+0x5a/0xa0 include/trace/events/lock.h:122 trace_contention_end.constprop.0+0xea/0x170 include/trace/events/lock.h:122 __pv_queued_spin_lock_slowpath+0x27e/0xc90 kernel/locking/qspinlock.c:557 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 htab_lock_bucket kernel/bpf/hashtab.c:167 [inline] htab_map_delete_elem+0x1c8/0x730 kernel/bpf/hashtab.c:1426 bpf_prog_1a158c95e143a564+0x45/0x4e 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:2406 [inline] bpf_trace_run2+0x231/0x590 kernel/trace/bpf_trace.c:2447 __bpf_trace_contention_end+0xca/0x110 include/trace/events/lock.h:122 __traceiter_contention_end+0x5a/0xa0 include/trace/events/lock.h:122 trace_contention_end+0xce/0x140 include/trace/events/lock.h:122 __mutex_lock_common kernel/locking/mutex.c:727 [inline] __mutex_lock+0x281/0x9c0 kernel/locking/mutex.c:752 rng_dev_read+0x128/0x720 drivers/char/hw_random/core.c:218 do_loop_readv_writev fs/read_write.c:761 [inline] do_loop_readv_writev fs/read_write.c:749 [inline] vfs_readv+0x6cb/0x8a0 fs/read_write.c:934 do_preadv fs/read_write.c:1049 [inline] __do_sys_preadv fs/read_write.c:1099 [inline] __se_sys_preadv fs/read_write.c:1094 [inline] __x64_sys_preadv+0x22b/0x310 fs/read_write.c:1094 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fa70184cea9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 71 19 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:00007fa701805218 EFLAGS: 00000246 ORIG_RAX: 0000000000000127 RAX: ffffffffffffffda RBX: 00007fa7018dc1a8 RCX: 00007fa70184cea9 RDX: 0000000000000001 RSI: 0000000020000240 RDI: 0000000000000003 RBP: 00007fa7018dc1a0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fa7018a325c R13: 7277682f7665642f R14: 00646e655f6e6f69 R15: 69746e65746e6f63 </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
