[v6.6] general protection fault in drr_qlen_notify
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syzbot
Jul 14, 2025, 7:18:35 PM7/14/25
to syzkaller...@googlegroups.com
Hello,
syzbot found the following issue on:
HEAD commit: 9247f4e6573a Linux 6.6.98
git tree: linux-6.6.y
console output: https://syzkaller.appspot.com/x/log.txt?x=14ddfd82580000
kernel config: https://syzkaller.appspot.com/x/.config?x=cfe840f14e117c98
dashboard link: https://syzkaller.appspot.com/bug?extid=0a760d7df2b7372532ad
compiler: Debian clang version 20.1.7 (++20250616065708+6146a88f6049-1~exp1~20250616065826.132), Debian LLD 20.1.7
Unfortunately, I don't have any reproducer for this issue yet.
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/3855f6db0ca8/disk-9247f4e6.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/fe3d6afeb3a6/vmlinux-9247f4e6.xz
kernel image: https://storage.googleapis.com/syzbot-assets/7d8784621ac6/bzImage-9247f4e6.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+0a760d...@syzkaller.appspotmail.com
general protection fault, probably for non-canonical address 0xdffffc000000000b: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000058-0x000000000000005f]
CPU: 1 PID: 11734 Comm: syz.4.1458 Not tainted 6.6.98-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:__list_del_entry_valid_or_report+0x23/0x130 lib/list_debug.c:49
Code: 00 00 00 00 00 66 90 f3 0f 1e fa 41 57 41 56 41 54 53 48 89 fb 49 bc 00 00 00 00 00 fc ff df 48 83 c7 08 48 89 f8 48 c1 e8 03 <42> 80 3c 20 00 74 05 e8 d1 c8 b7 fd 4c 8b 7b 08 48 89 d8 48 c1 e8
RSP: 0018:ffffc9000f136d48 EFLAGS: 00010202
RAX: 000000000000000b RBX: 0000000000000050 RCX: 0000000000080000
RDX: ffffc90019ca5000 RSI: 0000000000001692 RDI: 0000000000000058
RBP: dffffc0000000000 R08: ffff88804e105a00 R09: 0000000000000002
R10: 00000000ffffffff R11: 0000000000000002 R12: dffffc0000000000
R13: dffffc0000000000 R14: 0000000000000050 R15: ffff88807ad8e800
FS: 00007ff1f9d546c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000019580 CR3: 000000002f8d7000 CR4: 00000000003506e0
Call Trace:
<TASK>
__list_del_entry_valid include/linux/list.h:124 [inline]
__list_del_entry include/linux/list.h:215 [inline]
list_del_init include/linux/list.h:287 [inline]
drr_qlen_notify+0x2c/0xf0 net/sched/sch_drr.c:238
qdisc_tree_reduce_backlog+0x28b/0x470 net/sched/sch_api.c:810
fq_codel_change+0xa2d/0xde0 net/sched/sch_fq_codel.c:440
fq_codel_init+0x361/0x970 net/sched/sch_fq_codel.c:477
qdisc_create+0x8eb/0x1050 net/sched/sch_api.c:1322
tc_modify_qdisc+0xb13/0x1be0 net/sched/sch_api.c:-1
rtnetlink_rcv_msg+0x7c7/0xf10 net/core/rtnetlink.c:6475
netlink_rcv_skb+0x216/0x480 net/netlink/af_netlink.c:2537
netlink_unicast_kernel net/netlink/af_netlink.c:1323 [inline]
netlink_unicast+0x750/0x8c0 net/netlink/af_netlink.c:1349
netlink_sendmsg+0x8c1/0xbe0 net/netlink/af_netlink.c:1891
sock_sendmsg_nosec net/socket.c:730 [inline]
__sock_sendmsg net/socket.c:745 [inline]
____sys_sendmsg+0x5bf/0x950 net/socket.c:2595
___sys_sendmsg+0x220/0x290 net/socket.c:2649
__sys_sendmsg net/socket.c:2678 [inline]
__do_sys_sendmsg net/socket.c:2687 [inline]
__se_sys_sendmsg+0x1a5/0x270 net/socket.c:2685
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7ff1f8f8e929
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:00007ff1f9d54038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007ff1f91b6080 RCX: 00007ff1f8f8e929
RDX: 0000000000000800 RSI: 0000200000000100 RDI: 0000000000000004
RBP: 00007ff1f9010b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007ff1f91b6080 R15: 00007ffdbde92cd8
</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:__list_del_entry_valid_or_report+0x23/0x130 lib/list_debug.c:49
Code: 00 00 00 00 00 66 90 f3 0f 1e fa 41 57 41 56 41 54 53 48 89 fb 49 bc 00 00 00 00 00 fc ff df 48 83 c7 08 48 89 f8 48 c1 e8 03 <42> 80 3c 20 00 74 05 e8 d1 c8 b7 fd 4c 8b 7b 08 48 89 d8 48 c1 e8
RSP: 0018:ffffc9000f136d48 EFLAGS: 00010202
RAX: 000000000000000b RBX: 0000000000000050 RCX: 0000000000080000
RDX: ffffc90019ca5000 RSI: 0000000000001692 RDI: 0000000000000058
RBP: dffffc0000000000 R08: ffff88804e105a00 R09: 0000000000000002
R10: 00000000ffffffff R11: 0000000000000002 R12: dffffc0000000000
R13: dffffc0000000000 R14: 0000000000000050 R15: ffff88807ad8e800
FS: 00007ff1f9d546c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000019580 CR3: 000000002f8d7000 CR4: 00000000003506e0
----------------
Code disassembly (best guess):
0: 00 00 add %al,(%rax)
2: 00 00 add %al,(%rax)
4: 00 66 90 add %ah,-0x70(%rsi)
7: f3 0f 1e fa endbr64
b: 41 57 push %r15
d: 41 56 push %r14
f: 41 54 push %r12
11: 53 push %rbx
12: 48 89 fb mov %rdi,%rbx
15: 49 bc 00 00 00 00 00 movabs $0xdffffc0000000000,%r12
1c: fc ff df
1f: 48 83 c7 08 add $0x8,%rdi
23: 48 89 f8 mov %rdi,%rax
26: 48 c1 e8 03 shr $0x3,%rax
* 2a: 42 80 3c 20 00 cmpb $0x0,(%rax,%r12,1) <-- trapping instruction
2f: 74 05 je 0x36
31: e8 d1 c8 b7 fd call 0xfdb7c907
36: 4c 8b 7b 08 mov 0x8(%rbx),%r15
3a: 48 89 d8 mov %rbx,%rax
3d: 48 rex.W
3e: c1 .byte 0xc1
3f: e8 .byte 0xe8
---
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:
#syz fix: exact-commit-title
If you want to overwrite report's subsystems, reply with:
#syz set subsystems: new-subsystem
(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: 9247f4e6573a Linux 6.6.98
git tree: linux-6.6.y
console output: https://syzkaller.appspot.com/x/log.txt?x=14ddfd82580000
kernel config: https://syzkaller.appspot.com/x/.config?x=cfe840f14e117c98
dashboard link: https://syzkaller.appspot.com/bug?extid=0a760d7df2b7372532ad
compiler: Debian clang version 20.1.7 (++20250616065708+6146a88f6049-1~exp1~20250616065826.132), Debian LLD 20.1.7
Unfortunately, I don't have any reproducer for this issue yet.
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/3855f6db0ca8/disk-9247f4e6.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/fe3d6afeb3a6/vmlinux-9247f4e6.xz
kernel image: https://storage.googleapis.com/syzbot-assets/7d8784621ac6/bzImage-9247f4e6.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+0a760d...@syzkaller.appspotmail.com
general protection fault, probably for non-canonical address 0xdffffc000000000b: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000058-0x000000000000005f]
CPU: 1 PID: 11734 Comm: syz.4.1458 Not tainted 6.6.98-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:__list_del_entry_valid_or_report+0x23/0x130 lib/list_debug.c:49
Code: 00 00 00 00 00 66 90 f3 0f 1e fa 41 57 41 56 41 54 53 48 89 fb 49 bc 00 00 00 00 00 fc ff df 48 83 c7 08 48 89 f8 48 c1 e8 03 <42> 80 3c 20 00 74 05 e8 d1 c8 b7 fd 4c 8b 7b 08 48 89 d8 48 c1 e8
RSP: 0018:ffffc9000f136d48 EFLAGS: 00010202
RAX: 000000000000000b RBX: 0000000000000050 RCX: 0000000000080000
RDX: ffffc90019ca5000 RSI: 0000000000001692 RDI: 0000000000000058
RBP: dffffc0000000000 R08: ffff88804e105a00 R09: 0000000000000002
R10: 00000000ffffffff R11: 0000000000000002 R12: dffffc0000000000
R13: dffffc0000000000 R14: 0000000000000050 R15: ffff88807ad8e800
FS: 00007ff1f9d546c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000019580 CR3: 000000002f8d7000 CR4: 00000000003506e0
Call Trace:
<TASK>
__list_del_entry_valid include/linux/list.h:124 [inline]
__list_del_entry include/linux/list.h:215 [inline]
list_del_init include/linux/list.h:287 [inline]
drr_qlen_notify+0x2c/0xf0 net/sched/sch_drr.c:238
qdisc_tree_reduce_backlog+0x28b/0x470 net/sched/sch_api.c:810
fq_codel_change+0xa2d/0xde0 net/sched/sch_fq_codel.c:440
fq_codel_init+0x361/0x970 net/sched/sch_fq_codel.c:477
qdisc_create+0x8eb/0x1050 net/sched/sch_api.c:1322
tc_modify_qdisc+0xb13/0x1be0 net/sched/sch_api.c:-1
rtnetlink_rcv_msg+0x7c7/0xf10 net/core/rtnetlink.c:6475
netlink_rcv_skb+0x216/0x480 net/netlink/af_netlink.c:2537
netlink_unicast_kernel net/netlink/af_netlink.c:1323 [inline]
netlink_unicast+0x750/0x8c0 net/netlink/af_netlink.c:1349
netlink_sendmsg+0x8c1/0xbe0 net/netlink/af_netlink.c:1891
sock_sendmsg_nosec net/socket.c:730 [inline]
__sock_sendmsg net/socket.c:745 [inline]
____sys_sendmsg+0x5bf/0x950 net/socket.c:2595
___sys_sendmsg+0x220/0x290 net/socket.c:2649
__sys_sendmsg net/socket.c:2678 [inline]
__do_sys_sendmsg net/socket.c:2687 [inline]
__se_sys_sendmsg+0x1a5/0x270 net/socket.c:2685
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7ff1f8f8e929
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:00007ff1f9d54038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007ff1f91b6080 RCX: 00007ff1f8f8e929
RDX: 0000000000000800 RSI: 0000200000000100 RDI: 0000000000000004
RBP: 00007ff1f9010b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007ff1f91b6080 R15: 00007ffdbde92cd8
</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:__list_del_entry_valid_or_report+0x23/0x130 lib/list_debug.c:49
Code: 00 00 00 00 00 66 90 f3 0f 1e fa 41 57 41 56 41 54 53 48 89 fb 49 bc 00 00 00 00 00 fc ff df 48 83 c7 08 48 89 f8 48 c1 e8 03 <42> 80 3c 20 00 74 05 e8 d1 c8 b7 fd 4c 8b 7b 08 48 89 d8 48 c1 e8
RSP: 0018:ffffc9000f136d48 EFLAGS: 00010202
RAX: 000000000000000b RBX: 0000000000000050 RCX: 0000000000080000
RDX: ffffc90019ca5000 RSI: 0000000000001692 RDI: 0000000000000058
RBP: dffffc0000000000 R08: ffff88804e105a00 R09: 0000000000000002
R10: 00000000ffffffff R11: 0000000000000002 R12: dffffc0000000000
R13: dffffc0000000000 R14: 0000000000000050 R15: ffff88807ad8e800
FS: 00007ff1f9d546c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000019580 CR3: 000000002f8d7000 CR4: 00000000003506e0
----------------
Code disassembly (best guess):
0: 00 00 add %al,(%rax)
2: 00 00 add %al,(%rax)
4: 00 66 90 add %ah,-0x70(%rsi)
7: f3 0f 1e fa endbr64
b: 41 57 push %r15
d: 41 56 push %r14
f: 41 54 push %r12
11: 53 push %rbx
12: 48 89 fb mov %rdi,%rbx
15: 49 bc 00 00 00 00 00 movabs $0xdffffc0000000000,%r12
1c: fc ff df
1f: 48 83 c7 08 add $0x8,%rdi
23: 48 89 f8 mov %rdi,%rax
26: 48 c1 e8 03 shr $0x3,%rax
* 2a: 42 80 3c 20 00 cmpb $0x0,(%rax,%r12,1) <-- trapping instruction
2f: 74 05 je 0x36
31: e8 d1 c8 b7 fd call 0xfdb7c907
36: 4c 8b 7b 08 mov 0x8(%rbx),%r15
3a: 48 89 d8 mov %rbx,%rax
3d: 48 rex.W
3e: c1 .byte 0xc1
3f: e8 .byte 0xe8
---
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:
#syz fix: exact-commit-title
If you want to overwrite report's subsystems, reply with:
#syz set subsystems: new-subsystem
(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
Oct 25, 2025, 2:41:14 PM10/25/25
to syzkaller...@googlegroups.com
Auto-closing this bug as obsolete.
Crashes did not happen for a while, no reproducer and no activity.
Crashes did not happen for a while, no reproducer and no activity.
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