* [syzbot] [net?] general protection fault in qfq_qlen_notify
@ 2025-07-04 9:27 syzbot
2025-07-08 2:36 ` syzbot
0 siblings, 1 reply; 2+ messages in thread
From: syzbot @ 2025-07-04 9:27 UTC (permalink / raw)
To: davem, edumazet, horms, jhs, jiri, kuba, linux-kernel, netdev,
pabeni, syzkaller-bugs, xiyou.wangcong
Hello,
syzbot found the following issue on:
HEAD commit: 17bbde2e1716 Merge tag 'net-6.16-rc5' of git://git.kernel...
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1774b3d4580000
kernel config: https://syzkaller.appspot.com/x/.config?x=a6dba31fc9bb876c
dashboard link: https://syzkaller.appspot.com/bug?extid=4dadc5aecf80324d5a51
compiler: Debian clang version 20.1.7 (++20250616065708+6146a88f6049-1~exp1~20250616065826.132), Debian LLD 20.1.7
userspace arch: i386
Unfortunately, I don't have any reproducer for this issue yet.
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/224153e195ae/disk-17bbde2e.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/790493022e09/vmlinux-17bbde2e.xz
kernel image: https://storage.googleapis.com/syzbot-assets/67c6b016f914/bzImage-17bbde2e.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+4dadc5aecf80324d5a51@syzkaller.appspotmail.com
Oops: general protection fault, probably for non-canonical address 0xdffffc000000000b: 0000 [#1] SMP KASAN PTI
KASAN: null-ptr-deref in range [0x0000000000000058-0x000000000000005f]
CPU: 1 UID: 0 PID: 21481 Comm: syz.0.4721 Not tainted 6.16.0-rc4-syzkaller-00108-g17bbde2e1716 #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:list_empty include/linux/list.h:373 [inline]
RIP: 0010:qfq_qlen_notify+0x29/0x70 net/sched/sch_qfq.c:1422
Code: 90 f3 0f 1e fa 41 57 41 56 53 48 89 f3 49 89 fe e8 ac 6b 3f f8 4c 8d 7b 58 4c 89 f8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df <80> 3c 08 00 74 08 4c 89 ff e8 59 ee a2 f8 49 8b 07 4c 39 f8 74 1c
RSP: 0018:ffffc9000468efc8 EFLAGS: 00010202
RAX: 000000000000000b RBX: 0000000000000000 RCX: dffffc0000000000
RDX: ffffc9000c37b000 RSI: 0000000000000b34 RDI: 0000000000000b35
RBP: dffffc0000000000 R08: ffff88802c5f8000 R09: 0000000000000002
R10: 00000000ffffffff R11: ffffffff8980e2e0 R12: 0000000000000000
R13: ffff888036988000 R14: ffff888036988000 R15: 0000000000000058
FS: 0000000000000000(0000) GS:ffff888125d50000(0063) knlGS:00000000f50aeb40
CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: 0000000030117ff8 CR3: 000000007cd72000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 000000000000000e DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
qdisc_tree_reduce_backlog+0x299/0x480 net/sched/sch_api.c:811
fq_change+0x1519/0x1f50 net/sched/sch_fq.c:1147
fq_init+0x699/0x960 net/sched/sch_fq.c:1201
qdisc_create+0x7a9/0xea0 net/sched/sch_api.c:1324
__tc_modify_qdisc net/sched/sch_api.c:1749 [inline]
tc_modify_qdisc+0x1426/0x2010 net/sched/sch_api.c:1813
rtnetlink_rcv_msg+0x77c/0xb70 net/core/rtnetlink.c:6953
netlink_rcv_skb+0x205/0x470 net/netlink/af_netlink.c:2534
netlink_unicast_kernel net/netlink/af_netlink.c:1313 [inline]
netlink_unicast+0x758/0x8d0 net/netlink/af_netlink.c:1339
netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1883
sock_sendmsg_nosec net/socket.c:712 [inline]
__sock_sendmsg+0x219/0x270 net/socket.c:727
____sys_sendmsg+0x505/0x830 net/socket.c:2566
___sys_sendmsg+0x21f/0x2a0 net/socket.c:2620
__sys_sendmsg+0x164/0x220 net/socket.c:2652
do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline]
__do_fast_syscall_32+0xb6/0x2b0 arch/x86/entry/syscall_32.c:306
do_fast_syscall_32+0x34/0x80 arch/x86/entry/syscall_32.c:331
entry_SYSENTER_compat_after_hwframe+0x84/0x8e
RIP: 0023:0xf70be539
Code: 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90
RSP: 002b:00000000f50ae55c EFLAGS: 00000206 ORIG_RAX: 0000000000000172
RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 0000000080000200
RDX: 0000000004008000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:list_empty include/linux/list.h:373 [inline]
RIP: 0010:qfq_qlen_notify+0x29/0x70 net/sched/sch_qfq.c:1422
Code: 90 f3 0f 1e fa 41 57 41 56 53 48 89 f3 49 89 fe e8 ac 6b 3f f8 4c 8d 7b 58 4c 89 f8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df <80> 3c 08 00 74 08 4c 89 ff e8 59 ee a2 f8 49 8b 07 4c 39 f8 74 1c
RSP: 0018:ffffc9000468efc8 EFLAGS: 00010202
RAX: 000000000000000b RBX: 0000000000000000 RCX: dffffc0000000000
RDX: ffffc9000c37b000 RSI: 0000000000000b34 RDI: 0000000000000b35
RBP: dffffc0000000000 R08: ffff88802c5f8000 R09: 0000000000000002
R10: 00000000ffffffff R11: ffffffff8980e2e0 R12: 0000000000000000
R13: ffff888036988000 R14: ffff888036988000 R15: 0000000000000058
FS: 0000000000000000(0000) GS:ffff888125d50000(0063) knlGS:00000000f50aeb40
CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: 0000000030117ff8 CR3: 000000007cd72000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 000000000000000e DR6: 00000000ffff0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
0: 90 nop
1: f3 0f 1e fa endbr64
5: 41 57 push %r15
7: 41 56 push %r14
9: 53 push %rbx
a: 48 89 f3 mov %rsi,%rbx
d: 49 89 fe mov %rdi,%r14
10: e8 ac 6b 3f f8 call 0xf83f6bc1
15: 4c 8d 7b 58 lea 0x58(%rbx),%r15
19: 4c 89 f8 mov %r15,%rax
1c: 48 c1 e8 03 shr $0x3,%rax
20: 48 b9 00 00 00 00 00 movabs $0xdffffc0000000000,%rcx
27: fc ff df
* 2a: 80 3c 08 00 cmpb $0x0,(%rax,%rcx,1) <-- trapping instruction
2e: 74 08 je 0x38
30: 4c 89 ff mov %r15,%rdi
33: e8 59 ee a2 f8 call 0xf8a2ee91
38: 49 8b 07 mov (%r15),%rax
3b: 4c 39 f8 cmp %r15,%rax
3e: 74 1c je 0x5c
---
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.
If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title
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
^ permalink raw reply [flat|nested] 2+ messages in thread
* Re: [syzbot] [net?] general protection fault in qfq_qlen_notify
2025-07-04 9:27 [syzbot] [net?] general protection fault in qfq_qlen_notify syzbot
@ 2025-07-08 2:36 ` syzbot
0 siblings, 0 replies; 2+ messages in thread
From: syzbot @ 2025-07-08 2:36 UTC (permalink / raw)
To: davem, edumazet, horms, jhs, jiri, kuba, linux-kernel, netdev,
pabeni, syzkaller-bugs, xiyou.wangcong
syzbot has found a reproducer for the following issue on:
HEAD commit: d7b8f8e20813 Linux 6.16-rc5
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=17335f70580000
kernel config: https://syzkaller.appspot.com/x/.config?x=a09d8660a55f005f
dashboard link: https://syzkaller.appspot.com/bug?extid=4dadc5aecf80324d5a51
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=117ac28c580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=17505582580000
Downloadable assets:
disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/d900f083ada3/non_bootable_disk-d7b8f8e2.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/b7f4e475deea/vmlinux-d7b8f8e2.xz
kernel image: https://storage.googleapis.com/syzbot-assets/474d459b180b/bzImage-d7b8f8e2.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+4dadc5aecf80324d5a51@syzkaller.appspotmail.com
Oops: general protection fault, probably for non-canonical address 0xdffffc000000000b: 0000 [#1] SMP KASAN NOPTI
KASAN: null-ptr-deref in range [0x0000000000000058-0x000000000000005f]
CPU: 2 UID: 0 PID: 6105 Comm: syz.0.16 Not tainted 6.16.0-rc5-syzkaller #0 PREEMPT(full)
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
RIP: 0010:list_empty include/linux/list.h:373 [inline]
RIP: 0010:qfq_qlen_notify+0x32/0x230 net/sched/sch_qfq.c:1422
Code: 41 55 41 54 49 89 fc 55 53 48 89 f3 4c 8d 7b 58 48 83 ec 08 e8 1f b7 26 f8 4c 89 fa 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 <80> 3c 02 00 0f 85 67 01 00 00 48 8b 43 58 49 39 c7 0f 84 30 01 00
RSP: 0018:ffffc9000322f2c0 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 1ffff11006e3505a
RDX: 000000000000000b RSI: ffffffff89952f91 RDI: ffff8880371a8000
RBP: 00000000000afff2 R08: 0000000000000005 R09: 0000000000000000
R10: 00000000000afff2 R11: 0000000000000001 R12: ffff8880371a8000
R13: 0000000000000000 R14: ffffffff8ce8f1e0 R15: 0000000000000058
FS: 0000555583a75500(0000) GS:ffff8880d6918000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000019580 CR3: 0000000050c10000 CR4: 0000000000352ef0
Call Trace:
<TASK>
qdisc_tree_reduce_backlog+0x221/0x500 net/sched/sch_api.c:811
fq_codel_change+0xb1a/0x11b0 net/sched/sch_fq_codel.c:450
fq_codel_init+0x4ce/0xa60 net/sched/sch_fq_codel.c:487
qdisc_create+0x457/0xfc0 net/sched/sch_api.c:1324
__tc_modify_qdisc net/sched/sch_api.c:1749 [inline]
tc_modify_qdisc+0x12bb/0x2130 net/sched/sch_api.c:1813
rtnetlink_rcv_msg+0x3c9/0xe90 net/core/rtnetlink.c:6953
netlink_rcv_skb+0x155/0x420 net/netlink/af_netlink.c:2534
netlink_unicast_kernel net/netlink/af_netlink.c:1313 [inline]
netlink_unicast+0x53a/0x7f0 net/netlink/af_netlink.c:1339
netlink_sendmsg+0x8d1/0xdd0 net/netlink/af_netlink.c:1883
sock_sendmsg_nosec net/socket.c:712 [inline]
__sock_sendmsg net/socket.c:727 [inline]
____sys_sendmsg+0xa95/0xc70 net/socket.c:2566
___sys_sendmsg+0x134/0x1d0 net/socket.c:2620
__sys_sendmsg+0x16d/0x220 net/socket.c:2652
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f57a6b8e929
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffc86511388 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f57a6db5fa0 RCX: 00007f57a6b8e929
RDX: 0000000000000800 RSI: 0000200000000100 RDI: 0000000000000003
RBP: 00007f57a6c10b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f57a6db5fa0 R14: 00007f57a6db5fa0 R15: 0000000000000003
</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:list_empty include/linux/list.h:373 [inline]
RIP: 0010:qfq_qlen_notify+0x32/0x230 net/sched/sch_qfq.c:1422
Code: 41 55 41 54 49 89 fc 55 53 48 89 f3 4c 8d 7b 58 48 83 ec 08 e8 1f b7 26 f8 4c 89 fa 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 <80> 3c 02 00 0f 85 67 01 00 00 48 8b 43 58 49 39 c7 0f 84 30 01 00
RSP: 0018:ffffc9000322f2c0 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 1ffff11006e3505a
RDX: 000000000000000b RSI: ffffffff89952f91 RDI: ffff8880371a8000
RBP: 00000000000afff2 R08: 0000000000000005 R09: 0000000000000000
R10: 00000000000afff2 R11: 0000000000000001 R12: ffff8880371a8000
R13: 0000000000000000 R14: ffffffff8ce8f1e0 R15: 0000000000000058
FS: 0000555583a75500(0000) GS:ffff8880d6918000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000019580 CR3: 0000000050c10000 CR4: 0000000000352ef0
----------------
Code disassembly (best guess):
0: 41 55 push %r13
2: 41 54 push %r12
4: 49 89 fc mov %rdi,%r12
7: 55 push %rbp
8: 53 push %rbx
9: 48 89 f3 mov %rsi,%rbx
c: 4c 8d 7b 58 lea 0x58(%rbx),%r15
10: 48 83 ec 08 sub $0x8,%rsp
14: e8 1f b7 26 f8 call 0xf826b738
19: 4c 89 fa mov %r15,%rdx
1c: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax
23: fc ff df
26: 48 c1 ea 03 shr $0x3,%rdx
* 2a: 80 3c 02 00 cmpb $0x0,(%rdx,%rax,1) <-- trapping instruction
2e: 0f 85 67 01 00 00 jne 0x19b
34: 48 8b 43 58 mov 0x58(%rbx),%rax
38: 49 39 c7 cmp %rax,%r15
3b: 0f .byte 0xf
3c: 84 30 test %dh,(%rax)
3e: 01 00 add %eax,(%rax)
---
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.
^ permalink raw reply [flat|nested] 2+ messages in thread
end of thread, other threads:[~2025-07-08 2:36 UTC | newest]
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