Messages in this thread | | | Subject | Re: [syzbot] WARNING in bpf_test_run | From | Yonghong Song <> | Date | Thu, 1 Apr 2021 17:40:44 -0700 |
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On 4/1/21 3:05 PM, Yonghong Song wrote: > > > On 4/1/21 4:29 AM, syzbot wrote: >> Hello, >> >> syzbot found the following issue on: >> >> HEAD commit: 36e79851 libbpf: Preserve empty DATASEC BTFs during >> static.. >> git tree: bpf-next >> console output: >> https://syzkaller.appspot.com/x/log.txt?x=1569bb06d00000 >> kernel config: >> https://syzkaller.appspot.com/x/.config?x=7eff0f22b8563a5f >> dashboard link: >> https://syzkaller.appspot.com/bug?extid=774c590240616eaa3423 >> syz repro: >> https://syzkaller.appspot.com/x/repro.syz?x=17556b7cd00000 >> C reproducer: >> https://syzkaller.appspot.com/x/repro.c?x=1772be26d00000 >> >> The issue was bisected to: >> >> commit 997acaf6b4b59c6a9c259740312a69ea549cc684 >> Author: Mark Rutland <mark.rutland@arm.com> >> Date: Mon Jan 11 15:37:07 2021 +0000 >> >> lockdep: report broken irq restoration >> >> bisection log: >> https://syzkaller.appspot.com/x/bisect.txt?x=10197016d00000 >> final oops: >> https://syzkaller.appspot.com/x/report.txt?x=12197016d00000 >> console output: >> https://syzkaller.appspot.com/x/log.txt?x=14197016d00000 >> >> IMPORTANT: if you fix the issue, please add the following tag to the >> commit: >> Reported-by: syzbot+774c590240616eaa3423@syzkaller.appspotmail.com >> Fixes: 997acaf6b4b5 ("lockdep: report broken irq restoration") >> >> ------------[ cut here ]------------ >> WARNING: CPU: 0 PID: 8725 at include/linux/bpf-cgroup.h:193 >> bpf_cgroup_storage_set include/linux/bpf-cgroup.h:193 [inline] >> WARNING: CPU: 0 PID: 8725 at include/linux/bpf-cgroup.h:193 >> bpf_test_run+0x65e/0xaa0 net/bpf/test_run.c:109 > > I will look at this issue. Thanks! > >> Modules linked in: >> CPU: 0 PID: 8725 Comm: syz-executor927 Not tainted >> 5.12.0-rc4-syzkaller #0 >> Hardware name: Google Google Compute Engine/Google Compute Engine, >> BIOS Google 01/01/2011 >> RIP: 0010:bpf_cgroup_storage_set include/linux/bpf-cgroup.h:193 [inline] >> RIP: 0010:bpf_test_run+0x65e/0xaa0 net/bpf/test_run.c:109 >> Code: e9 29 fe ff ff e8 b2 9d 3a fa 41 83 c6 01 bf 08 00 00 00 44 89 >> f6 e8 51 a5 3a fa 41 83 fe 08 0f 85 74 fc ff ff e8 92 9d 3a fa <0f> 0b >> bd f0 ffff ff e9 5c fd ff ff e8 81 9d 3a fa 83 c5 01 bf 08 >> RSP: 0018:ffffc900017bfaf0 EFLAGS: 00010293 >> RAX: 0000000000000000 RBX: ffffc90000f29000 RCX: 0000000000000000 >> RDX: ffff88801bc68000 RSI: ffffffff8739543e RDI: 0000000000000003 >> RBP: 0000000000000007 R08: 0000000000000008 R09: 0000000000000001 >> R10: ffffffff8739542f R11: 0000000000000000 R12: dffffc0000000000 >> R13: ffff888021dd54c0 R14: 0000000000000008 R15: 0000000000000000 >> FS: 00007f00157d7700(0000) GS:ffff8880b9c00000(0000) >> knlGS:0000000000000000 >> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 >> CR2: 00007f0015795718 CR3: 00000000157ae000 CR4: 00000000001506f0 >> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 >> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 >> Call Trace: >> bpf_prog_test_run_skb+0xabc/0x1c70 net/bpf/test_run.c:628 >> bpf_prog_test_run kernel/bpf/syscall.c:3132 [inline] >> __do_sys_bpf+0x218b/0x4f40 kernel/bpf/syscall.c:4411 >> do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
Run on my qemu (4 cpus) with C reproducer and I cannot reproduce the result. It already ran 30 minutes and still running. Checked the code, it is just doing a lot of parallel bpf_prog_test_run's.
The failure is in the below WARN_ON_ONCE code:
175 static inline int bpf_cgroup_storage_set(struct bpf_cgroup_storage 176 *storage[MAX_BPF_CGROUP_STORAGE_TYPE]) 177 { 178 enum bpf_cgroup_storage_type stype; 179 int i, err = 0; 180 181 preempt_disable(); 182 for (i = 0; i < BPF_CGROUP_STORAGE_NEST_MAX; i++) { 183 if (unlikely(this_cpu_read(bpf_cgroup_storage_info[i].task) != NULL)) 184 continue; 185 186 this_cpu_write(bpf_cgroup_storage_info[i].task, current); 187 for_each_cgroup_storage_type(stype) 188 this_cpu_write(bpf_cgroup_storage_info[i].storage[stype], 189 storage[stype]); 190 goto out; 191 } 192 err = -EBUSY; 193 WARN_ON_ONCE(1); 194 195 out: 196 preempt_enable(); 197 return err; 198 }
Basically it shows the stress test triggered a warning due to limited kernel resource.
>> entry_SYSCALL_64_after_hwframe+0x44/0xae >> RIP: 0033:0x446199 >> Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 11 15 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 ffff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 >> RSP: 002b:00007f00157d72f8 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 >> RAX: ffffffffffffffda RBX: 00000000004cb440 RCX: 0000000000446199 >> RDX: 0000000000000028 RSI: 0000000020000080 RDI: 000000000000000a >> RBP: 000000000049b074 R08: 0000000000000000 R09: 0000000000000000 >> R10: 0000000000000000 R11: 0000000000000246 R12: f9abde7200f522cd >> R13: 3952ddf3af240c07 R14: 1631e0d82d3fa99d R15: 00000000004cb448 >> >> >> --- >> 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@googlegroups.com. >> >> syzbot will keep track of this issue. See: >> https://goo.gl/tpsmEJ#status >> for how to communicate with syzbot. >> For information about bisection process see: >> https://goo.gl/tpsmEJ#bisection >> syzbot can test patches for this issue, for details see: >> https://goo.gl/tpsmEJ#testing-patches >>
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