[v6.1] possible deadlock in force_sig_info_to_task
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syzbot
May 17, 2024, 4:42:36 PMMay 17
to syzkaller...@googlegroups.com
Hello,
syzbot found the following issue on:
HEAD commit: 4078fa637fcd Linux 6.1.91
git tree: linux-6.1.y
console output: https://syzkaller.appspot.com/x/log.txt?x=111b04f4980000
kernel config: https://syzkaller.appspot.com/x/.config?x=715ba80acfd3def4
dashboard link: https://syzkaller.appspot.com/bug?extid=7d53f856fccbed9cb3ec
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/2443dfe91c62/disk-4078fa63.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/12dbc2af3348/vmlinux-4078fa63.xz
kernel image: https://storage.googleapis.com/syzbot-assets/da3589238e32/bzImage-4078fa63.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+7d53f8...@syzkaller.appspotmail.com
======================================================
WARNING: possible circular locking dependency detected
6.1.91-syzkaller #0 Not tainted
------------------------------------------------------
syz-executor.2/4111 is trying to acquire lock:
ffff8880569ec0d8 (&sighand->siglock){-.-.}-{2:2}, at: force_sig_info_to_task+0x69/0x470 kernel/signal.c:1333
but task is already holding lock:
ffff8880b993aa18 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:537
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #2 (&rq->__lock){-.-.}-{2:2}:
lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662
_raw_spin_lock_nested+0x2d/0x40 kernel/locking/spinlock.c:378
raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:537
raw_spin_rq_lock kernel/sched/sched.h:1354 [inline]
rq_lock kernel/sched/sched.h:1644 [inline]
task_fork_fair+0x5d/0x350 kernel/sched/fair.c:11869
sched_cgroup_fork+0x374/0x400 kernel/sched/core.c:4686
copy_process+0x2442/0x4060 kernel/fork.c:2384
kernel_clone+0x222/0x920 kernel/fork.c:2682
user_mode_thread+0x12e/0x190 kernel/fork.c:2758
rest_init+0x23/0x300 init/main.c:699
start_kernel+0x0/0x53f init/main.c:894
start_kernel+0x496/0x53f init/main.c:1141
secondary_startup_64_no_verify+0xcf/0xdb
-> #1 (&p->pi_lock){-.-.}-{2:2}:
lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
_raw_spin_lock_irqsave+0xd1/0x120 kernel/locking/spinlock.c:162
try_to_wake_up+0xad/0x12e0 kernel/sched/core.c:4112
signal_wake_up_state kernel/signal.c:780 [inline]
signal_wake_up include/linux/sched/signal.h:457 [inline]
complete_signal+0x796/0xbd0 kernel/signal.c:1074
__send_signal_locked+0xb1a/0xdc0 kernel/signal.c:1194
do_notify_parent+0xe2b/0x1100 kernel/signal.c:2120
exit_notify kernel/exit.c:744 [inline]
do_exit+0x172e/0x26a0 kernel/exit.c:889
do_group_exit+0x202/0x2b0 kernel/exit.c:1019
__do_sys_exit_group kernel/exit.c:1030 [inline]
__se_sys_exit_group kernel/exit.c:1028 [inline]
__x64_sys_exit_group+0x3b/0x40 kernel/exit.c:1028
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
-> #0 (&sighand->siglock){-.-.}-{2:2}:
check_prev_add kernel/locking/lockdep.c:3090 [inline]
check_prevs_add kernel/locking/lockdep.c:3209 [inline]
validate_chain+0x1661/0x5950 kernel/locking/lockdep.c:3825
__lock_acquire+0x125b/0x1f80 kernel/locking/lockdep.c:5049
lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
_raw_spin_lock_irqsave+0xd1/0x120 kernel/locking/spinlock.c:162
force_sig_info_to_task+0x69/0x470 kernel/signal.c:1333
force_sig_fault_to_task kernel/signal.c:1724 [inline]
force_sig_fault+0x127/0x1d0 kernel/signal.c:1730
__bad_area_nosemaphore+0x126/0x730 arch/x86/mm/fault.c:828
handle_page_fault arch/x86/mm/fault.c:1462 [inline]
exc_page_fault+0x30d/0x660 arch/x86/mm/fault.c:1518
asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:570
copy_user_short_string+0x36/0x40 arch/x86/lib/copy_user_64.S:250
copy_user_generic arch/x86/include/asm/uaccess_64.h:37 [inline]
raw_copy_from_user arch/x86/include/asm/uaccess_64.h:52 [inline]
__copy_from_user_inatomic include/linux/uaccess.h:65 [inline]
copy_from_user_nofault+0xb1/0x140 mm/maccess.c:125
bpf_probe_read_user_common kernel/trace/bpf_trace.c:167 [inline]
____bpf_probe_read_user kernel/trace/bpf_trace.c:176 [inline]
bpf_probe_read_user+0x26/0x70 kernel/trace/bpf_trace.c:173
bpf_prog_d20f016a5d369cb4+0x35/0x37
bpf_dispatcher_nop_func include/linux/bpf.h:989 [inline]
__bpf_prog_run include/linux/filter.h:603 [inline]
bpf_prog_run include/linux/filter.h:610 [inline]
__bpf_trace_run kernel/trace/bpf_trace.c:2273 [inline]
bpf_trace_run4+0x253/0x470 kernel/trace/bpf_trace.c:2314
__traceiter_sched_switch+0x91/0xc0 include/trace/events/sched.h:222
trace_sched_switch include/trace/events/sched.h:222 [inline]
__schedule+0x2116/0x4550 kernel/sched/core.c:6555
preempt_schedule_irq+0xf7/0x1c0 kernel/sched/core.c:6870
irqentry_exit+0x53/0x80 kernel/entry/common.c:439
asm_sysvec_reschedule_ipi+0x16/0x20 arch/x86/include/asm/idtentry.h:658
__put_user_nocheck_8+0x0/0x21
__do_sys_gettimeofday kernel/time/time.c:147 [inline]
__se_sys_gettimeofday+0xd5/0x230 kernel/time/time.c:140
emulate_vsyscall+0xc5c/0x1240 arch/x86/entry/vsyscall/vsyscall_64.c:247
do_user_addr_fault arch/x86/mm/fault.c:1337 [inline]
handle_page_fault arch/x86/mm/fault.c:1462 [inline]
exc_page_fault+0x154/0x660 arch/x86/mm/fault.c:1518
asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:570
_end+0x6d3da000/0x0
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-executor.2/4111:
#0: ffff8880b993aa18 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:537
#1: ffffffff8d12ac80 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
#1: ffffffff8d12ac80 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline]
#1: ffffffff8d12ac80 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2272 [inline]
#1: ffffffff8d12ac80 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run4+0x16a/0x470 kernel/trace/bpf_trace.c:2314
stack backtrace:
CPU: 1 PID: 4111 Comm: syz-executor.2 Not tainted 6.1.91-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106
check_noncircular+0x2fa/0x3b0 kernel/locking/lockdep.c:2170
check_prev_add kernel/locking/lockdep.c:3090 [inline]
check_prevs_add kernel/locking/lockdep.c:3209 [inline]
validate_chain+0x1661/0x5950 kernel/locking/lockdep.c:3825
__lock_acquire+0x125b/0x1f80 kernel/locking/lockdep.c:5049
lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
_raw_spin_lock_irqsave+0xd1/0x120 kernel/locking/spinlock.c:162
force_sig_info_to_task+0x69/0x470 kernel/signal.c:1333
force_sig_fault_to_task kernel/signal.c:1724 [inline]
force_sig_fault+0x127/0x1d0 kernel/signal.c:1730
__bad_area_nosemaphore+0x126/0x730 arch/x86/mm/fault.c:828
handle_page_fault arch/x86/mm/fault.c:1462 [inline]
exc_page_fault+0x30d/0x660 arch/x86/mm/fault.c:1518
asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:570
RIP: 0010:copy_user_short_string+0x36/0x40 arch/x86/lib/copy_user_64.S:252
Code: 06 4c 89 07 48 8d 76 08 48 8d 7f 08 ff c9 75 ee 21 d2 74 10 89 d1 8a 06 88 07 48 ff c6 48 ff c7 ff c9 75 f2 31 c0 0f 01 ca c3 <8d> 14 ca eb 02 89 ca eb a1 90 0f 01 cb 83 fa 08 0f 82 95 00 00 00
RSP: 0000:ffffc900031cf8c0 EFLAGS: 00050002
RAX: 000000000000000e RBX: dffffc0000000000 RCX: 0000000000000001
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffc900031cf928
RBP: ffff88801fcad2f0 R08: 0000000000000005 R09: ffffffff81eeb403
R10: 0000000000000003 R11: ffff88801fcabb80 R12: 1ffff11003f95a5e
R13: 0000000000000008 R14: ffffc900031cf928 R15: 0000000000000000
copy_user_generic arch/x86/include/asm/uaccess_64.h:37 [inline]
raw_copy_from_user arch/x86/include/asm/uaccess_64.h:52 [inline]
__copy_from_user_inatomic include/linux/uaccess.h:65 [inline]
copy_from_user_nofault+0xb1/0x140 mm/maccess.c:125
bpf_probe_read_user_common kernel/trace/bpf_trace.c:167 [inline]
____bpf_probe_read_user kernel/trace/bpf_trace.c:176 [inline]
bpf_probe_read_user+0x26/0x70 kernel/trace/bpf_trace.c:173
bpf_prog_d20f016a5d369cb4+0x35/0x37
bpf_dispatcher_nop_func include/linux/bpf.h:989 [inline]
__bpf_prog_run include/linux/filter.h:603 [inline]
bpf_prog_run include/linux/filter.h:610 [inline]
__bpf_trace_run kernel/trace/bpf_trace.c:2273 [inline]
bpf_trace_run4+0x253/0x470 kernel/trace/bpf_trace.c:2314
__traceiter_sched_switch+0x91/0xc0 include/trace/events/sched.h:222
trace_sched_switch include/trace/events/sched.h:222 [inline]
__schedule+0x2116/0x4550 kernel/sched/core.c:6555
preempt_schedule_irq+0xf7/0x1c0 kernel/sched/core.c:6870
irqentry_exit+0x53/0x80 kernel/entry/common.c:439
asm_sysvec_reschedule_ipi+0x16/0x20 arch/x86/include/asm/idtentry.h:658
RIP: 0010:__put_user_nocheck_8+0x0/0x21
Code: ff ff 7f 00 00 48 39 d9 73 34 0f 01 cb 89 01 31 c9 0f 01 ca c3 66 0f 1f 44 00 00 48 bb f9 ef ff ff ff 7f 00 00 48 39 d9 73 14 <0f> 01 cb 48 89 01 31 c9 0f 01 ca c3 0f 1f 44 00 00 0f 01 ca b9 f2
RSP: 0000:ffffc900031cfd98 EFLAGS: 00000283
RAX: 000000006647c0ed RBX: 00007fffffffeff9 RCX: 0000000000000019
RDX: 0000000000000000 RSI: ffffffff8aec1340 RDI: ffffffff8b3d4560
RBP: ffffc900031cfe58 R08: dffffc0000000000 R09: fffffbfff1ce710e
R10: 0000000000000000 R11: dffffc0000000001 R12: ffffc900031cfde0
R13: dffffc0000000000 R14: 1ffff92000639fb8 R15: 0000000000000019
__do_sys_gettimeofday kernel/time/time.c:147 [inline]
__se_sys_gettimeofday+0xd5/0x230 kernel/time/time.c:140
emulate_vsyscall+0xc5c/0x1240 arch/x86/entry/vsyscall/vsyscall_64.c:247
do_user_addr_fault arch/x86/mm/fault.c:1337 [inline]
handle_page_fault arch/x86/mm/fault.c:1462 [inline]
exc_page_fault+0x154/0x660 arch/x86/mm/fault.c:1518
asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:570
RIP: 0033:_end+0x6d3da000/0x0
Code: Unable to access opcode bytes at 0xffffffffff5fffd6.
RSP: 002b:00007f84df1aab38 EFLAGS: 00010246
RAX: ffffffffffffffda RBX: 00007f84de5abf80 RCX: 00007f84de47cee9
RDX: 00007f84df1aab40 RSI: 00007f84df1aac70 RDI: 0000000000000019
RBP: 00007f84de4c949e R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000007 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007f84de5abf80 R15: 00007ffd104eeb88
</TASK>
----------------
Code disassembly (best guess), 1 bytes skipped:
0: 4c 89 07 mov %r8,(%rdi)
3: 48 8d 76 08 lea 0x8(%rsi),%rsi
7: 48 8d 7f 08 lea 0x8(%rdi),%rdi
b: ff c9 dec %ecx
d: 75 ee jne 0xfffffffd
f: 21 d2 and %edx,%edx
11: 74 10 je 0x23
13: 89 d1 mov %edx,%ecx
15: 8a 06 mov (%rsi),%al
17: 88 07 mov %al,(%rdi)
19: 48 ff c6 inc %rsi
1c: 48 ff c7 inc %rdi
1f: ff c9 dec %ecx
21: 75 f2 jne 0x15
23: 31 c0 xor %eax,%eax
25: 0f 01 ca clac
28: c3 ret
* 29: 8d 14 ca lea (%rdx,%rcx,8),%edx <-- trapping instruction
2c: eb 02 jmp 0x30
2e: 89 ca mov %ecx,%edx
30: eb a1 jmp 0xffffffd3
32: 90 nop
33: 0f 01 cb stac
36: 83 fa 08 cmp $0x8,%edx
39: 0f 82 95 00 00 00 jb 0xd4
---
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 syzk...@googlegroups.com.
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:
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If you want to overwrite report's subsystems, reply with:
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(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
syzbot found the following issue on:
HEAD commit: 4078fa637fcd Linux 6.1.91
git tree: linux-6.1.y
console output: https://syzkaller.appspot.com/x/log.txt?x=111b04f4980000
kernel config: https://syzkaller.appspot.com/x/.config?x=715ba80acfd3def4
dashboard link: https://syzkaller.appspot.com/bug?extid=7d53f856fccbed9cb3ec
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/2443dfe91c62/disk-4078fa63.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/12dbc2af3348/vmlinux-4078fa63.xz
kernel image: https://storage.googleapis.com/syzbot-assets/da3589238e32/bzImage-4078fa63.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+7d53f8...@syzkaller.appspotmail.com
======================================================
WARNING: possible circular locking dependency detected
6.1.91-syzkaller #0 Not tainted
------------------------------------------------------
syz-executor.2/4111 is trying to acquire lock:
ffff8880569ec0d8 (&sighand->siglock){-.-.}-{2:2}, at: force_sig_info_to_task+0x69/0x470 kernel/signal.c:1333
but task is already holding lock:
ffff8880b993aa18 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:537
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #2 (&rq->__lock){-.-.}-{2:2}:
lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662
_raw_spin_lock_nested+0x2d/0x40 kernel/locking/spinlock.c:378
raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:537
raw_spin_rq_lock kernel/sched/sched.h:1354 [inline]
rq_lock kernel/sched/sched.h:1644 [inline]
task_fork_fair+0x5d/0x350 kernel/sched/fair.c:11869
sched_cgroup_fork+0x374/0x400 kernel/sched/core.c:4686
copy_process+0x2442/0x4060 kernel/fork.c:2384
kernel_clone+0x222/0x920 kernel/fork.c:2682
user_mode_thread+0x12e/0x190 kernel/fork.c:2758
rest_init+0x23/0x300 init/main.c:699
start_kernel+0x0/0x53f init/main.c:894
start_kernel+0x496/0x53f init/main.c:1141
secondary_startup_64_no_verify+0xcf/0xdb
-> #1 (&p->pi_lock){-.-.}-{2:2}:
lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
_raw_spin_lock_irqsave+0xd1/0x120 kernel/locking/spinlock.c:162
try_to_wake_up+0xad/0x12e0 kernel/sched/core.c:4112
signal_wake_up_state kernel/signal.c:780 [inline]
signal_wake_up include/linux/sched/signal.h:457 [inline]
complete_signal+0x796/0xbd0 kernel/signal.c:1074
__send_signal_locked+0xb1a/0xdc0 kernel/signal.c:1194
do_notify_parent+0xe2b/0x1100 kernel/signal.c:2120
exit_notify kernel/exit.c:744 [inline]
do_exit+0x172e/0x26a0 kernel/exit.c:889
do_group_exit+0x202/0x2b0 kernel/exit.c:1019
__do_sys_exit_group kernel/exit.c:1030 [inline]
__se_sys_exit_group kernel/exit.c:1028 [inline]
__x64_sys_exit_group+0x3b/0x40 kernel/exit.c:1028
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
-> #0 (&sighand->siglock){-.-.}-{2:2}:
check_prev_add kernel/locking/lockdep.c:3090 [inline]
check_prevs_add kernel/locking/lockdep.c:3209 [inline]
validate_chain+0x1661/0x5950 kernel/locking/lockdep.c:3825
__lock_acquire+0x125b/0x1f80 kernel/locking/lockdep.c:5049
lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
_raw_spin_lock_irqsave+0xd1/0x120 kernel/locking/spinlock.c:162
force_sig_info_to_task+0x69/0x470 kernel/signal.c:1333
force_sig_fault_to_task kernel/signal.c:1724 [inline]
force_sig_fault+0x127/0x1d0 kernel/signal.c:1730
__bad_area_nosemaphore+0x126/0x730 arch/x86/mm/fault.c:828
handle_page_fault arch/x86/mm/fault.c:1462 [inline]
exc_page_fault+0x30d/0x660 arch/x86/mm/fault.c:1518
asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:570
copy_user_short_string+0x36/0x40 arch/x86/lib/copy_user_64.S:250
copy_user_generic arch/x86/include/asm/uaccess_64.h:37 [inline]
raw_copy_from_user arch/x86/include/asm/uaccess_64.h:52 [inline]
__copy_from_user_inatomic include/linux/uaccess.h:65 [inline]
copy_from_user_nofault+0xb1/0x140 mm/maccess.c:125
bpf_probe_read_user_common kernel/trace/bpf_trace.c:167 [inline]
____bpf_probe_read_user kernel/trace/bpf_trace.c:176 [inline]
bpf_probe_read_user+0x26/0x70 kernel/trace/bpf_trace.c:173
bpf_prog_d20f016a5d369cb4+0x35/0x37
bpf_dispatcher_nop_func include/linux/bpf.h:989 [inline]
__bpf_prog_run include/linux/filter.h:603 [inline]
bpf_prog_run include/linux/filter.h:610 [inline]
__bpf_trace_run kernel/trace/bpf_trace.c:2273 [inline]
bpf_trace_run4+0x253/0x470 kernel/trace/bpf_trace.c:2314
__traceiter_sched_switch+0x91/0xc0 include/trace/events/sched.h:222
trace_sched_switch include/trace/events/sched.h:222 [inline]
__schedule+0x2116/0x4550 kernel/sched/core.c:6555
preempt_schedule_irq+0xf7/0x1c0 kernel/sched/core.c:6870
irqentry_exit+0x53/0x80 kernel/entry/common.c:439
asm_sysvec_reschedule_ipi+0x16/0x20 arch/x86/include/asm/idtentry.h:658
__put_user_nocheck_8+0x0/0x21
__do_sys_gettimeofday kernel/time/time.c:147 [inline]
__se_sys_gettimeofday+0xd5/0x230 kernel/time/time.c:140
emulate_vsyscall+0xc5c/0x1240 arch/x86/entry/vsyscall/vsyscall_64.c:247
do_user_addr_fault arch/x86/mm/fault.c:1337 [inline]
handle_page_fault arch/x86/mm/fault.c:1462 [inline]
exc_page_fault+0x154/0x660 arch/x86/mm/fault.c:1518
asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:570
_end+0x6d3da000/0x0
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-executor.2/4111:
#0: ffff8880b993aa18 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:537
#1: ffffffff8d12ac80 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
#1: ffffffff8d12ac80 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline]
#1: ffffffff8d12ac80 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2272 [inline]
#1: ffffffff8d12ac80 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run4+0x16a/0x470 kernel/trace/bpf_trace.c:2314
stack backtrace:
CPU: 1 PID: 4111 Comm: syz-executor.2 Not tainted 6.1.91-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106
check_noncircular+0x2fa/0x3b0 kernel/locking/lockdep.c:2170
check_prev_add kernel/locking/lockdep.c:3090 [inline]
check_prevs_add kernel/locking/lockdep.c:3209 [inline]
validate_chain+0x1661/0x5950 kernel/locking/lockdep.c:3825
__lock_acquire+0x125b/0x1f80 kernel/locking/lockdep.c:5049
lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
_raw_spin_lock_irqsave+0xd1/0x120 kernel/locking/spinlock.c:162
force_sig_info_to_task+0x69/0x470 kernel/signal.c:1333
force_sig_fault_to_task kernel/signal.c:1724 [inline]
force_sig_fault+0x127/0x1d0 kernel/signal.c:1730
__bad_area_nosemaphore+0x126/0x730 arch/x86/mm/fault.c:828
handle_page_fault arch/x86/mm/fault.c:1462 [inline]
exc_page_fault+0x30d/0x660 arch/x86/mm/fault.c:1518
asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:570
RIP: 0010:copy_user_short_string+0x36/0x40 arch/x86/lib/copy_user_64.S:252
Code: 06 4c 89 07 48 8d 76 08 48 8d 7f 08 ff c9 75 ee 21 d2 74 10 89 d1 8a 06 88 07 48 ff c6 48 ff c7 ff c9 75 f2 31 c0 0f 01 ca c3 <8d> 14 ca eb 02 89 ca eb a1 90 0f 01 cb 83 fa 08 0f 82 95 00 00 00
RSP: 0000:ffffc900031cf8c0 EFLAGS: 00050002
RAX: 000000000000000e RBX: dffffc0000000000 RCX: 0000000000000001
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffc900031cf928
RBP: ffff88801fcad2f0 R08: 0000000000000005 R09: ffffffff81eeb403
R10: 0000000000000003 R11: ffff88801fcabb80 R12: 1ffff11003f95a5e
R13: 0000000000000008 R14: ffffc900031cf928 R15: 0000000000000000
copy_user_generic arch/x86/include/asm/uaccess_64.h:37 [inline]
raw_copy_from_user arch/x86/include/asm/uaccess_64.h:52 [inline]
__copy_from_user_inatomic include/linux/uaccess.h:65 [inline]
copy_from_user_nofault+0xb1/0x140 mm/maccess.c:125
bpf_probe_read_user_common kernel/trace/bpf_trace.c:167 [inline]
____bpf_probe_read_user kernel/trace/bpf_trace.c:176 [inline]
bpf_probe_read_user+0x26/0x70 kernel/trace/bpf_trace.c:173
bpf_prog_d20f016a5d369cb4+0x35/0x37
bpf_dispatcher_nop_func include/linux/bpf.h:989 [inline]
__bpf_prog_run include/linux/filter.h:603 [inline]
bpf_prog_run include/linux/filter.h:610 [inline]
__bpf_trace_run kernel/trace/bpf_trace.c:2273 [inline]
bpf_trace_run4+0x253/0x470 kernel/trace/bpf_trace.c:2314
__traceiter_sched_switch+0x91/0xc0 include/trace/events/sched.h:222
trace_sched_switch include/trace/events/sched.h:222 [inline]
__schedule+0x2116/0x4550 kernel/sched/core.c:6555
preempt_schedule_irq+0xf7/0x1c0 kernel/sched/core.c:6870
irqentry_exit+0x53/0x80 kernel/entry/common.c:439
asm_sysvec_reschedule_ipi+0x16/0x20 arch/x86/include/asm/idtentry.h:658
RIP: 0010:__put_user_nocheck_8+0x0/0x21
Code: ff ff 7f 00 00 48 39 d9 73 34 0f 01 cb 89 01 31 c9 0f 01 ca c3 66 0f 1f 44 00 00 48 bb f9 ef ff ff ff 7f 00 00 48 39 d9 73 14 <0f> 01 cb 48 89 01 31 c9 0f 01 ca c3 0f 1f 44 00 00 0f 01 ca b9 f2
RSP: 0000:ffffc900031cfd98 EFLAGS: 00000283
RAX: 000000006647c0ed RBX: 00007fffffffeff9 RCX: 0000000000000019
RDX: 0000000000000000 RSI: ffffffff8aec1340 RDI: ffffffff8b3d4560
RBP: ffffc900031cfe58 R08: dffffc0000000000 R09: fffffbfff1ce710e
R10: 0000000000000000 R11: dffffc0000000001 R12: ffffc900031cfde0
R13: dffffc0000000000 R14: 1ffff92000639fb8 R15: 0000000000000019
__do_sys_gettimeofday kernel/time/time.c:147 [inline]
__se_sys_gettimeofday+0xd5/0x230 kernel/time/time.c:140
emulate_vsyscall+0xc5c/0x1240 arch/x86/entry/vsyscall/vsyscall_64.c:247
do_user_addr_fault arch/x86/mm/fault.c:1337 [inline]
handle_page_fault arch/x86/mm/fault.c:1462 [inline]
exc_page_fault+0x154/0x660 arch/x86/mm/fault.c:1518
asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:570
RIP: 0033:_end+0x6d3da000/0x0
Code: Unable to access opcode bytes at 0xffffffffff5fffd6.
RSP: 002b:00007f84df1aab38 EFLAGS: 00010246
RAX: ffffffffffffffda RBX: 00007f84de5abf80 RCX: 00007f84de47cee9
RDX: 00007f84df1aab40 RSI: 00007f84df1aac70 RDI: 0000000000000019
RBP: 00007f84de4c949e R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000007 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007f84de5abf80 R15: 00007ffd104eeb88
</TASK>
----------------
Code disassembly (best guess), 1 bytes skipped:
0: 4c 89 07 mov %r8,(%rdi)
3: 48 8d 76 08 lea 0x8(%rsi),%rsi
7: 48 8d 7f 08 lea 0x8(%rdi),%rdi
b: ff c9 dec %ecx
d: 75 ee jne 0xfffffffd
f: 21 d2 and %edx,%edx
11: 74 10 je 0x23
13: 89 d1 mov %edx,%ecx
15: 8a 06 mov (%rsi),%al
17: 88 07 mov %al,(%rdi)
19: 48 ff c6 inc %rsi
1c: 48 ff c7 inc %rdi
1f: ff c9 dec %ecx
21: 75 f2 jne 0x15
23: 31 c0 xor %eax,%eax
25: 0f 01 ca clac
28: c3 ret
* 29: 8d 14 ca lea (%rdx,%rcx,8),%edx <-- trapping instruction
2c: eb 02 jmp 0x30
2e: 89 ca mov %ecx,%edx
30: eb a1 jmp 0xffffffd3
32: 90 nop
33: 0f 01 cb stac
36: 83 fa 08 cmp $0x8,%edx
39: 0f 82 95 00 00 00 jb 0xd4
---
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