All of lore.kernel.org
 help / color / mirror / Atom feed
From: syzbot <syzbot+c49e17557ddb5725583d@syzkaller.appspotmail.com>
To: hdanton@sina.com, linux-kernel@vger.kernel.org,
	syzkaller-bugs@googlegroups.com
Subject: Re: [syzbot] possible deadlock in bpf_trace_printk
Date: Fri, 10 Jun 2022 08:29:07 -0700	[thread overview]
Message-ID: <00000000000065c75c05e11999d6@google.com> (raw)
In-Reply-To: <20220610151650.1358-1-hdanton@sina.com>

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
WARNING in bpf_bprintf_prepare

------------[ cut here ]------------
WARNING: CPU: 1 PID: 2971 at kernel/bpf/helpers.c:791 try_get_fmt_tmp_buf kernel/bpf/helpers.c:791 [inline]
WARNING: CPU: 1 PID: 2971 at kernel/bpf/helpers.c:791 bpf_bprintf_prepare+0xf31/0x11a0 kernel/bpf/helpers.c:839
Modules linked in:
CPU: 1 PID: 2971 Comm: udevd Not tainted 5.18.0-syzkaller-12122-gd678cbd2f867-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:try_get_fmt_tmp_buf kernel/bpf/helpers.c:791 [inline]
RIP: 0010:bpf_bprintf_prepare+0xf31/0x11a0 kernel/bpf/helpers.c:839
Code: ff e8 93 f8 ea ff 48 83 7c 24 08 00 41 bd 04 00 00 00 0f 85 8a fa ff ff e8 7c f8 ea ff 8d 6b 03 e9 f7 f6 ff ff e8 6f f8 ea ff <0f> 0b 65 ff 0d de b4 73 7e bf 01 00 00 00 41 bc f0 ff ff ff e8 16
RSP: 0018:ffffc90002d7e780 EFLAGS: 00010093
RAX: 0000000000000000 RBX: 0000000000000002 RCX: 0000000000000000
RDX: ffff88807dfabb00 RSI: ffffffff818f8be1 RDI: 0000000000000005
RBP: ffffc90002d7e8b8 R08: 0000000000000005 R09: 0000000000000003
R10: 0000000000000004 R11: 0000000000000001 R12: 0000000000000003
R13: 0000000000000004 R14: ffffc90002d7e970 R15: 0000000000000003
FS:  00007f17e75cf840(0000) GS:ffff8880b9b00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055a120075288 CR3: 000000001d494000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 ____bpf_trace_printk kernel/trace/bpf_trace.c:385 [inline]
 bpf_trace_printk+0x10d/0x260 kernel/trace/bpf_trace.c:374
 bpf_prog_0605f9f479290f07+0x2f/0x33
 bpf_dispatcher_nop_func include/linux/bpf.h:869 [inline]
 __bpf_prog_run include/linux/filter.h:628 [inline]
 bpf_prog_run include/linux/filter.h:635 [inline]
 __bpf_trace_run kernel/trace/bpf_trace.c:2050 [inline]
 bpf_trace_run2+0x110/0x340 kernel/trace/bpf_trace.c:2087
 __bpf_trace_contention_begin+0xb5/0xf0 include/trace/events/lock.h:95
 trace_contention_begin.constprop.0+0xda/0x1b0 include/trace/events/lock.h:95
 __pv_queued_spin_lock_slowpath+0x103/0xb50 kernel/locking/qspinlock.c:405
 pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:591 [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+0x200/0x2a0 kernel/locking/spinlock_debug.c:115
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:111 [inline]
 _raw_spin_lock_irqsave+0x41/0x50 kernel/locking/spinlock.c:162
 ____bpf_trace_printk kernel/trace/bpf_trace.c:390 [inline]
 bpf_trace_printk+0x134/0x260 kernel/trace/bpf_trace.c:374
 bpf_prog_0605f9f479290f07+0x2f/0x33
 bpf_dispatcher_nop_func include/linux/bpf.h:869 [inline]
 __bpf_prog_run include/linux/filter.h:628 [inline]
 bpf_prog_run include/linux/filter.h:635 [inline]
 __bpf_trace_run kernel/trace/bpf_trace.c:2050 [inline]
 bpf_trace_run2+0x110/0x340 kernel/trace/bpf_trace.c:2087
 __bpf_trace_contention_begin+0xb5/0xf0 include/trace/events/lock.h:95
 trace_contention_begin.constprop.0+0xda/0x1b0 include/trace/events/lock.h:95
 __pv_queued_spin_lock_slowpath+0x103/0xb50 kernel/locking/qspinlock.c:405
 pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:591 [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+0x200/0x2a0 kernel/locking/spinlock_debug.c:115
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:111 [inline]
 _raw_spin_lock_irqsave+0x41/0x50 kernel/locking/spinlock.c:162
 ____bpf_trace_printk kernel/trace/bpf_trace.c:390 [inline]
 bpf_trace_printk+0x134/0x260 kernel/trace/bpf_trace.c:374
 bpf_prog_0605f9f479290f07+0x2f/0x33
 bpf_dispatcher_nop_func include/linux/bpf.h:869 [inline]
 __bpf_prog_run include/linux/filter.h:628 [inline]
 bpf_prog_run include/linux/filter.h:635 [inline]
 __bpf_trace_run kernel/trace/bpf_trace.c:2050 [inline]
 bpf_trace_run2+0x110/0x340 kernel/trace/bpf_trace.c:2087
 __bpf_trace_contention_begin+0xb5/0xf0 include/trace/events/lock.h:95
 trace_contention_begin.constprop.0+0xda/0x1b0 include/trace/events/lock.h:95
 __pv_queued_spin_lock_slowpath+0x103/0xb50 kernel/locking/qspinlock.c:405
 pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:591 [inline]
 queued_spin_lock_slowpath arch/x86/include/asm/qspinlock.h:51 [inline]
 queued_spin_lock include/asm-generic/qspinlock.h:114 [inline]
 lockdep_lock kernel/locking/lockdep.c:143 [inline]
 graph_lock kernel/locking/lockdep.c:169 [inline]
 lookup_chain_cache_add kernel/locking/lockdep.c:3764 [inline]
 validate_chain kernel/locking/lockdep.c:3797 [inline]
 __lock_acquire+0x333f/0x5660 kernel/locking/lockdep.c:5053
 lock_acquire kernel/locking/lockdep.c:5665 [inline]
 lock_acquire+0x1ab/0x570 kernel/locking/lockdep.c:5630
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
 _raw_spin_lock_irqsave+0x39/0x50 kernel/locking/spinlock.c:162
 ____bpf_trace_printk kernel/trace/bpf_trace.c:390 [inline]
 bpf_trace_printk+0x134/0x260 kernel/trace/bpf_trace.c:374
 bpf_prog_0605f9f479290f07+0x2f/0x33
 bpf_dispatcher_nop_func include/linux/bpf.h:869 [inline]
 __bpf_prog_run include/linux/filter.h:628 [inline]
 bpf_prog_run include/linux/filter.h:635 [inline]
 __bpf_trace_run kernel/trace/bpf_trace.c:2050 [inline]
 bpf_trace_run2+0x110/0x340 kernel/trace/bpf_trace.c:2087
 __bpf_trace_contention_begin+0xb5/0xf0 include/trace/events/lock.h:95
 trace_contention_begin+0xc0/0x150 include/trace/events/lock.h:95
 __mutex_lock_common kernel/locking/mutex.c:605 [inline]
 __mutex_lock+0x13c/0x1350 kernel/locking/mutex.c:747
 kernfs_get_open_node fs/kernfs/file.c:524 [inline]
 kernfs_fop_open+0x7e8/0xe00 fs/kernfs/file.c:693
 do_dentry_open+0x4a1/0x11f0 fs/open.c:848
 do_open fs/namei.c:3527 [inline]
 path_openat+0x1c71/0x2910 fs/namei.c:3660
 do_filp_open+0x1aa/0x400 fs/namei.c:3687
 do_sys_openat2+0x16d/0x4c0 fs/open.c:1278
 do_sys_open fs/open.c:1294 [inline]
 __do_sys_openat fs/open.c:1310 [inline]
 __se_sys_openat fs/open.c:1305 [inline]
 __x64_sys_openat+0x13f/0x1f0 fs/open.c:1305
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x46/0xb0
RIP: 0033:0x7f17e7125697
Code: 25 00 00 41 00 3d 00 00 41 00 74 37 64 8b 04 25 18 00 00 00 85 c0 75 5b 44 89 e2 48 89 ee bf 9c ff ff ff b8 01 01 00 00 0f 05 <48> 3d 00 f0 ff ff 0f 87 85 00 00 00 48 83 c4 68 5d 41 5c c3 0f 1f
RSP: 002b:00007ffcc7516d30 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 000055a11ff7ccc0 RCX: 00007f17e7125697
RDX: 0000000000080000 RSI: 00007ffcc7516e68 RDI: 00000000ffffff9c
RBP: 00007ffcc7516e68 R08: 0000000000000008 R09: 0000000000000001
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000080000
R13: 000055a11ff7ccc0 R14: 0000000000000001 R15: 0000000000000000
 </TASK>


Tested on:

commit:         d678cbd2 xsk: Fix handling of invalid descriptors in X..
git tree:       https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf.git
console output: https://syzkaller.appspot.com/x/log.txt?x=17515e73f00000
kernel config:  https://syzkaller.appspot.com/x/.config?x=fc5a30a131480a80
dashboard link: https://syzkaller.appspot.com/bug?extid=c49e17557ddb5725583d
compiler:       gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
patch:          https://syzkaller.appspot.com/x/patch.diff?x=145a11bff00000


       reply	other threads:[~2022-06-10 15:29 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <20220610151650.1358-1-hdanton@sina.com>
2022-06-10 15:29 ` syzbot [this message]
     [not found] <20220611005547.1454-1-hdanton@sina.com>
2022-06-11  1:38 ` [syzbot] possible deadlock in bpf_trace_printk syzbot
2022-06-09 17:07 syzbot

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=00000000000065c75c05e11999d6@google.com \
    --to=syzbot+c49e17557ddb5725583d@syzkaller.appspotmail.com \
    --cc=hdanton@sina.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=syzkaller-bugs@googlegroups.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.