On Sat, 27 Apr 2024 13:00:42 -0700 > syzbot has found a reproducer for the following issue on: > > HEAD commit: 5eb4573ea63d Merge tag 'soc-fixes-6.9-2' of git://git.kern.. > git tree: upstream > console+strace: https://syzkaller.appspot.com/x/log.txt?x=17b2b240980000 > kernel config: https://syzkaller.appspot.com/x/.config?x=3d46aa9d7a44f40d > dashboard link: https://syzkaller.appspot.com/bug?extid=83e7f982ca045ab4405c > 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=120f79ef180000 > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=13a1cd27180000 > > Downloadable assets: > disk image: https://storage.googleapis.com/syzbot-assets/d647177a878d/disk-5eb4573e.raw.xz > vmlinux: https://storage.googleapis.com/syzbot-assets/977f32ca169c/vmlinux-5eb4573e.xz > kernel image: https://storage.googleapis.com/syzbot-assets/67f3b92c1012/bzImage-5eb4573e.xz > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > Reported-by: syzbot+83e7f982ca045ab4405c@xxxxxxxxxxxxxxxxxxxxxxxxx > > ====================================================== > WARNING: possible circular locking dependency detected > 6.9.0-rc5-syzkaller-00296-g5eb4573ea63d #0 Not tainted > ------------------------------------------------------ > syz-executor324/5151 is trying to acquire lock: > ffff88802a6c8018 (&sighand->siglock){....}-{2:2}, at: force_sig_info_to_task+0x68/0x580 kernel/signal.c:1334 > > but task is already holding lock: > ffff8880b943e658 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:559 > > which lock already depends on the new lock. > > > the existing dependency chain (in reverse order) is: > > -> #2 (&rq->__lock){-.-.}-{2:2}: > lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754 > _raw_spin_lock_nested+0x31/0x40 kernel/locking/spinlock.c:378 > raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:559 > raw_spin_rq_lock kernel/sched/sched.h:1387 [inline] > rq_lock kernel/sched/sched.h:1701 [inline] > task_fork_fair+0x61/0x1e0 kernel/sched/fair.c:12635 > sched_cgroup_fork+0x37c/0x410 kernel/sched/core.c:4845 > copy_process+0x2217/0x3df0 kernel/fork.c:2499 > kernel_clone+0x223/0x870 kernel/fork.c:2797 > user_mode_thread+0x132/0x1a0 kernel/fork.c:2875 > rest_init+0x23/0x300 init/main.c:704 > start_kernel+0x47a/0x500 init/main.c:1081 > x86_64_start_reservations+0x2a/0x30 arch/x86/kernel/head64.c:507 > x86_64_start_kernel+0x99/0xa0 arch/x86/kernel/head64.c:488 > common_startup_64+0x13e/0x147 > > -> #1 (&p->pi_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 > class_raw_spinlock_irqsave_constructor include/linux/spinlock.h:553 [inline] > try_to_wake_up+0xb0/0x1470 kernel/sched/core.c:4262 > signal_wake_up_state+0xb4/0x120 kernel/signal.c:773 > signal_wake_up include/linux/sched/signal.h:448 [inline] > complete_signal+0x94a/0xcf0 kernel/signal.c:1065 > __send_signal_locked+0xb1b/0xdc0 kernel/signal.c:1185 > do_notify_parent+0xd96/0x10a0 kernel/signal.c:2143 > exit_notify kernel/exit.c:757 [inline] > do_exit+0x1811/0x27e0 kernel/exit.c:898 > do_group_exit+0x207/0x2c0 kernel/exit.c:1027 > __do_sys_exit_group kernel/exit.c:1038 [inline] > __se_sys_exit_group kernel/exit.c:1036 [inline] > __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1036 > 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 (&sighand->siglock){....}-{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 > force_sig_info_to_task+0x68/0x580 kernel/signal.c:1334 > force_sig_fault_to_task kernel/signal.c:1733 [inline] > force_sig_fault+0x12c/0x1d0 kernel/signal.c:1738 > __bad_area_nosemaphore+0x127/0x780 arch/x86/mm/fault.c:814 > handle_page_fault arch/x86/mm/fault.c:1505 [inline] Given page fault with runqueue locked, bpf makes trouble instead of helping anything in this case. > exc_page_fault+0x612/0x8e0 arch/x86/mm/fault.c:1563 > asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 > rep_movs_alternative+0x22/0x70 arch/x86/lib/copy_user_64.S:48 > copy_user_generic arch/x86/include/asm/uaccess_64.h:110 [inline] > raw_copy_from_user arch/x86/include/asm/uaccess_64.h:125 [inline] > __copy_from_user_inatomic include/linux/uaccess.h:87 [inline] > copy_from_user_nofault+0xbc/0x150 mm/maccess.c:125 > bpf_probe_read_user_common kernel/trace/bpf_trace.c:179 [inline] > ____bpf_probe_read_compat kernel/trace/bpf_trace.c:292 [inline] > bpf_probe_read_compat+0xe9/0x180 kernel/trace/bpf_trace.c:288 > bpf_prog_1878750df62aa1fb+0x48/0x4a > 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_run4+0x25a/0x490 kernel/trace/bpf_trace.c:2422 > __traceiter_sched_switch+0x98/0xd0 include/trace/events/sched.h:222 > trace_sched_switch include/trace/events/sched.h:222 [inline] > __schedule+0x2535/0x4a00 kernel/sched/core.c:6743 > preempt_schedule_common+0x84/0xd0 kernel/sched/core.c:6925 > preempt_schedule+0xe1/0xf0 kernel/sched/core.c:6949 > preempt_schedule_thunk+0x1a/0x30 arch/x86/entry/thunk_64.S:12 > __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] > _raw_spin_unlock_irqrestore+0x130/0x140 kernel/locking/spinlock.c:194 > spin_unlock_irqrestore include/linux/spinlock.h:406 [inline] > force_sig_info_to_task+0x41c/0x580 kernel/signal.c:1356 > force_sig_fault_to_task kernel/signal.c:1733 [inline] > force_sig_fault+0x12c/0x1d0 kernel/signal.c:1738 > __bad_area_nosemaphore+0x127/0x780 arch/x86/mm/fault.c:814 > handle_page_fault arch/x86/mm/fault.c:1505 [inline] > exc_page_fault+0x612/0x8e0 arch/x86/mm/fault.c:1563 > asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 > __put_user_handle_exception+0x0/0x10 > __do_sys_gettimeofday kernel/time/time.c:147 [inline] > __se_sys_gettimeofday+0xd9/0x240 kernel/time/time.c:140 > emulate_vsyscall+0xe23/0x1290 arch/x86/entry/vsyscall/vsyscall_64.c:247 > do_user_addr_fault arch/x86/mm/fault.c:1346 [inline] > handle_page_fault arch/x86/mm/fault.c:1505 [inline] > exc_page_fault+0x160/0x8e0 arch/x86/mm/fault.c:1563 > asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 > _end+0x6a9da000/0x0 > > other info that might help us debug this: > > Chain exists of: > &sighand->siglock --> &p->pi_lock --> &rq->__lock > > Possible unsafe locking scenario: > > CPU0 CPU1 > ---- ---- > lock(&rq->__lock); > lock(&p->pi_lock); > lock(&rq->__lock); > lock(&sighand->siglock); > > *** DEADLOCK *** > > 2 locks held by syz-executor324/5151: > #0: ffff8880b943e658 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:559 > #1: ffffffff8e334d20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline] > #1: ffffffff8e334d20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline] > #1: ffffffff8e334d20 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2380 [inline] > #1: ffffffff8e334d20 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run4+0x16e/0x490 kernel/trace/bpf_trace.c:2422 > > stack backtrace: > CPU: 0 PID: 5151 Comm: syz-executor324 Not tainted 6.9.0-rc5-syzkaller-00296-g5eb4573ea63d #0 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 > 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 > force_sig_info_to_task+0x68/0x580 kernel/signal.c:1334 > force_sig_fault_to_task kernel/signal.c:1733 [inline] > force_sig_fault+0x12c/0x1d0 kernel/signal.c:1738 > __bad_area_nosemaphore+0x127/0x780 arch/x86/mm/fault.c:814 > handle_page_fault arch/x86/mm/fault.c:1505 [inline] > exc_page_fault+0x612/0x8e0 arch/x86/mm/fault.c:1563 > asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 > RIP: 0010:rep_movs_alternative+0x22/0x70 arch/x86/lib/copy_user_64.S:50 > Code: 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 83 f9 40 73 40 83 f9 08 73 21 85 c9 74 0f 8a 06 88 07 48 ff c7 48 ff c6 48 ff c9 75 f1 <c3> cc cc cc cc 66 0f 1f 84 00 00 00 00 00 48 8b 06 48 89 07 48 83 > RSP: 0000:ffffc90004137468 EFLAGS: 00050002 > RAX: ffffffff8205ce4e RBX: dffffc0000000000 RCX: 0000000000000002 > RDX: 0000000000000000 RSI: 0000000000000900 RDI: ffffc900041374e8 > RBP: ffff88802d039784 R08: 0000000000000005 R09: ffffffff8205ce37 > R10: 0000000000000003 R11: ffff88802d038000 R12: 1ffff11005a072f0 > R13: 0000000000000900 R14: 0000000000000002 R15: ffffc900041374e8 > copy_user_generic arch/x86/include/asm/uaccess_64.h:110 [inline] > raw_copy_from_user arch/x86/include/asm/uaccess_64.h:125 [inline] > __copy_from_user_inatomic include/linux/uaccess.h:87 [inline] > copy_from_user_nofault+0xbc/0x150 mm/maccess.c:125 > bpf_probe_read_user_common kernel/trace/bpf_trace.c:179 [inline] > ____bpf_probe_read_compat kernel/trace/bpf_trace.c:292 [inline] > bpf_probe_read_compat+0xe9/0x180 kernel/trace/bpf_trace.c:288 > bpf_prog_1878750df62aa1fb+0x48/0x4a > 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_run4+0x25a/0x490 kernel/trace/bpf_trace.c:2422 > __traceiter_sched_switch+0x98/0xd0 include/trace/events/sched.h:222 > trace_sched_switch include/trace/events/sched.h:222 [inline] > __schedule+0x2535/0x4a00 kernel/sched/core.c:6743 > preempt_schedule_common+0x84/0xd0 kernel/sched/core.c:6925 > preempt_schedule+0xe1/0xf0 kernel/sched/core.c:6949 > preempt_schedule_thunk+0x1a/0x30 arch/x86/entry/thunk_64.S:12 > __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] > _raw_spin_unlock_irqrestore+0x130/0x140 kernel/locking/spinlock.c:194 > spin_unlock_irqrestore include/linux/spinlock.h:406 [inline] > force_sig_info_to_task+0x41c/0x580 kernel/signal.c:1356 > force_sig_fault_to_task kernel/signal.c:1733 [inline] > force_sig_fault+0x12c/0x1d0 kernel/signal.c:1738 > __bad_area_nosemaphore+0x127/0x780 arch/x86/mm/fault.c:814 > handle_page_fault arch/x86/mm/fault.c:1505 [inline] > exc_page_fault+0x612/0x8e0 arch/x86/mm/fault.c:1563 > asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 > RIP: 0010:__put_user_handle_exception+0x0/0x10 arch/x86/lib/putuser.S:125 > Code: 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 0f 01 cb 48 89 01 31 c9 0f 01 ca c3 cc cc cc cc 66 2e 0f 1f 84 00 00 00 00 00 66 90 <0f> 01 ca b9 f2 ff ff ff c3 cc cc cc cc 0f 1f 00 90 90 90 90 90 90 > RSP: 0000:ffffc90004137d98 EFLAGS: 00050202 > RAX: 00000000662d5943 RBX: 0000000000000000 RCX: 0000000000000019 > RDX: 0000000000000000 RSI: ffffffff8bcaca20 RDI: ffffffff8c1eaba0 > RBP: ffffc90004137e50 R08: ffffffff8fa7cd6f R09: 1ffffffff1f4f9ad > R10: dffffc0000000000 R11: fffffbfff1f4f9ae R12: ffffc90004137de0 > R13: dffffc0000000000 R14: 1ffff92000826fb8 R15: 0000000000000019 > __do_sys_gettimeofday kernel/time/time.c:147 [inline] > __se_sys_gettimeofday+0xd9/0x240 kernel/time/time.c:140 > emulate_vsyscall+0xe23/0x1290 arch/x86/entry/vsyscall/vsyscall_64.c:247 > do_user_addr_fault arch/x86/mm/fault.c:1346 [inline] > handle_page_fault arch/x86/mm/fault.c:1505 [inline] > exc_page_fault+0x160/0x8e0 arch/x86/mm/fault.c:1563 > asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 > RIP: 0033:_end+0x6a9da000/0x0 > Code: Unable to access opcode bytes at 0xffffffffff5fffd6. > RSP: 002b:00007fbb40c81c78 EFLAGS: 00010246 > RAX: ffffffffffffffda RBX: 00007fbb40d73418 RCX: 00007fbb40ce97d9 > RDX: 00007fbb40c81c80 RSI: 00007fbb40c81db0 RDI: 0000000000000019 > RBP: 00007fbb40d73410 R08: 0000000000000000 R09: 0000000000000000 > R10: 0000000000000007 R11: 0000000000000246 R12: 00007fbb40d402b0 > R13: 77735f6465686373 R14: 66aa589070d556b8 R15: 0400000000000004 > </TASK> > syz-executor324[5151] vsyscall fault (exploit attempt?) ip:ffffffffff600000 cs:33 sp:7fbb40c81c78 ax:ffffffffffffffda si:7fbb40c81db0 di:19 > ---------------- > Code disassembly (best guess): > 0: 90 nop > 1: 90 nop > 2: 90 nop > 3: 90 nop > 4: 90 nop > 5: 90 nop > 6: 90 nop > 7: 90 nop > 8: f3 0f 1e fa endbr64 > c: 48 83 f9 40 cmp $0x40,%rcx > 10: 73 40 jae 0x52 > 12: 83 f9 08 cmp $0x8,%ecx > 15: 73 21 jae 0x38 > 17: 85 c9 test %ecx,%ecx > 19: 74 0f je 0x2a > 1b: 8a 06 mov (%rsi),%al > 1d: 88 07 mov %al,(%rdi) > 1f: 48 ff c7 inc %rdi > 22: 48 ff c6 inc %rsi > 25: 48 ff c9 dec %rcx > 28: 75 f1 jne 0x1b > * 2a: c3 ret <-- trapping instruction > 2b: cc int3 > 2c: cc int3 > 2d: cc int3 > 2e: cc int3 > 2f: 66 0f 1f 84 00 00 00 nopw 0x0(%rax,%rax,1) > 36: 00 00 > 38: 48 8b 06 mov (%rsi),%rax > 3b: 48 89 07 mov %rax,(%rdi) > 3e: 48 rex.W > 3f: 83 .byte 0x83 > > > --- > 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. >
