syzbot


general protection fault in htb_qlen_notify

Status: premoderation: reported on 2025/07/14 13:36
Reported-by: syzbot+549c55059ad4193875c5@syzkaller.appspotmail.com
First crash: 10d, last: 4d02h
Similar bugs (4)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.6 general protection fault in htb_qlen_notify 2 1 8d20h 8d20h 0/2 upstream: reported on 2025/07/16 10:29
linux-5.15 general protection fault in htb_qlen_notify origin:lts-only 8 C 9 13d 14d 0/3 upstream: reported C repro on 2025/07/10 18:58
upstream general protection fault in htb_qlen_notify net 10 C done 166 12d 21d 27/29 upstream: reported C repro on 2025/07/03 08:17
linux-6.1 general protection fault in htb_qlen_notify origin:lts-only 2 C 4 12d 14d 0/3 upstream: reported C repro on 2025/07/10 18:56

Sample crash report:
general protection fault, probably for non-canonical address 0xdffffc0000000036: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x00000000000001b0-0x00000000000001b7]
CPU: 1 PID: 24710 Comm: syz.3.6648 Not tainted 5.15.188-syzkaller-android13-5.15.188_r00 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:htb_deactivate net/sched/sch_htb.c:609 [inline]
RIP: 0010:htb_qlen_notify+0x30/0xc0 net/sched/sch_htb.c:1507
Code: 41 56 41 55 41 54 53 49 89 f6 49 89 ff 49 bc 00 00 00 00 00 fc ff df e8 be e1 94 fd 4d 8d ae b0 01 00 00 4c 89 eb 48 c1 eb 03 <42> 0f b6 04 23 84 c0 75 58 45 8b 65 00 31 ff 44 89 e6 e8 49 e5 94
RSP: 0018:ffffc90000ef6e90 EFLAGS: 00010206
RAX: ffffffff83d3ce12 RBX: 0000000000000036 RCX: 0000000000080000
RDX: ffffc9000738e000 RSI: 00000000000001e2 RDI: 00000000000001e3
RBP: ffffc90000ef6eb8 R08: ffff888131f593c0 R09: 0000000000000002
R10: 00000000ffffffff R11: 0000000000000002 R12: dffffc0000000000
R13: 00000000000001b0 R14: 0000000000000000 R15: ffff88811079e000
FS:  00007f06d11516c0(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffeb169c148 CR3: 00000001155d8000 CR4: 00000000003506a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 000000000000000c DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 qdisc_tree_reduce_backlog+0x1e8/0x340 net/sched/sch_api.c:800
 fq_codel_change+0xa71/0xf10 net/sched/sch_fq_codel.c:438
 fq_codel_init+0x342/0xa20 net/sched/sch_fq_codel.c:475
 qdisc_create+0x7ed/0x11a0 net/sched/sch_api.c:1261
 tc_modify_qdisc+0x896/0x1480 net/sched/sch_api.c:-1
 rtnetlink_rcv_msg+0x9e4/0xb90 net/core/rtnetlink.c:5650
 netlink_rcv_skb+0x1e0/0x430 net/netlink/af_netlink.c:2493
 rtnetlink_rcv+0x1c/0x20 net/core/rtnetlink.c:5668
 netlink_unicast_kernel net/netlink/af_netlink.c:1315 [inline]
 netlink_unicast+0x87c/0xa40 net/netlink/af_netlink.c:1341
 netlink_sendmsg+0x86a/0xb70 net/netlink/af_netlink.c:1909
 sock_sendmsg_nosec net/socket.c:704 [inline]
 __sock_sendmsg net/socket.c:716 [inline]
 ____sys_sendmsg+0x5a2/0x8c0 net/socket.c:2436
 ___sys_sendmsg+0x1f0/0x260 net/socket.c:2490
 __sys_sendmsg net/socket.c:2519 [inline]
 __do_sys_sendmsg net/socket.c:2528 [inline]
 __se_sys_sendmsg net/socket.c:2526 [inline]
 __x64_sys_sendmsg+0x1e2/0x2a0 net/socket.c:2526
 x64_sys_call+0x4b/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:47
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f06d2ae89a9
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:00007f06d1151038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f06d2d0ffa0 RCX: 00007f06d2ae89a9
RDX: 0000000000004000 RSI: 0000200000000040 RDI: 0000000000000006
RBP: 00007f06d2b6ad69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f06d2d0ffa0 R15: 00007ffc7270edc8
 </TASK>
Modules linked in:
---[ end trace f5a5b2a2d31430e0 ]---
RIP: 0010:htb_deactivate net/sched/sch_htb.c:609 [inline]
RIP: 0010:htb_qlen_notify+0x30/0xc0 net/sched/sch_htb.c:1507
Code: 41 56 41 55 41 54 53 49 89 f6 49 89 ff 49 bc 00 00 00 00 00 fc ff df e8 be e1 94 fd 4d 8d ae b0 01 00 00 4c 89 eb 48 c1 eb 03 <42> 0f b6 04 23 84 c0 75 58 45 8b 65 00 31 ff 44 89 e6 e8 49 e5 94
RSP: 0018:ffffc90000ef6e90 EFLAGS: 00010206
RAX: ffffffff83d3ce12 RBX: 0000000000000036 RCX: 0000000000080000
RDX: ffffc9000738e000 RSI: 00000000000001e2 RDI: 00000000000001e3
RBP: ffffc90000ef6eb8 R08: ffff888131f593c0 R09: 0000000000000002
R10: 00000000ffffffff R11: 0000000000000002 R12: dffffc0000000000
R13: 00000000000001b0 R14: 0000000000000000 R15: ffff88811079e000
FS:  00007f06d11516c0(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffeb169c148 CR3: 00000001155d8000 CR4: 00000000003506a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 000000000000000c DR6: 00000000ffff0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	41 56                	push   %r14
   2:	41 55                	push   %r13
   4:	41 54                	push   %r12
   6:	53                   	push   %rbx
   7:	49 89 f6             	mov    %rsi,%r14
   a:	49 89 ff             	mov    %rdi,%r15
   d:	49 bc 00 00 00 00 00 	movabs $0xdffffc0000000000,%r12
  14:	fc ff df
  17:	e8 be e1 94 fd       	call   0xfd94e1da
  1c:	4d 8d ae b0 01 00 00 	lea    0x1b0(%r14),%r13
  23:	4c 89 eb             	mov    %r13,%rbx
  26:	48 c1 eb 03          	shr    $0x3,%rbx
* 2a:	42 0f b6 04 23       	movzbl (%rbx,%r12,1),%eax <-- trapping instruction
  2f:	84 c0                	test   %al,%al
  31:	75 58                	jne    0x8b
  33:	45 8b 65 00          	mov    0x0(%r13),%r12d
  37:	31 ff                	xor    %edi,%edi
  39:	44 89 e6             	mov    %r12d,%esi
  3c:	e8                   	.byte 0xe8
  3d:	49 e5 94             	rex.WB in $0x94,%eax

Crashes (13):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/07/21 04:12 android13-5.15-lts 6b619c45dff5 7117feec .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 general protection fault in htb_qlen_notify
2025/07/19 22:28 android13-5.15-lts 6b619c45dff5 7117feec .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 general protection fault in htb_qlen_notify
2025/07/19 10:23 android13-5.15-lts 6b619c45dff5 7117feec .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 general protection fault in htb_qlen_notify
2025/07/18 20:23 android13-5.15-lts 6b619c45dff5 7117feec .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 general protection fault in htb_qlen_notify
2025/07/18 20:23 android13-5.15-lts 6b619c45dff5 7117feec .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 general protection fault in htb_qlen_notify
2025/07/18 20:23 android13-5.15-lts 6b619c45dff5 7117feec .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 general protection fault in htb_qlen_notify
2025/07/18 02:31 android13-5.15-lts 6b619c45dff5 88248e14 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 general protection fault in htb_qlen_notify
2025/07/18 00:22 android13-5.15-lts 6b619c45dff5 0d1223f1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 general protection fault in htb_qlen_notify
2025/07/18 00:22 android13-5.15-lts 6b619c45dff5 0d1223f1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 general protection fault in htb_qlen_notify
2025/07/16 20:35 android13-5.15-lts 6b619c45dff5 44f8051e .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 general protection fault in htb_qlen_notify
2025/07/16 07:30 android13-5.15-lts 6b619c45dff5 124ec9cc .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 general protection fault in htb_qlen_notify
2025/07/15 17:53 android13-5.15-lts 6b619c45dff5 03fcfc4b .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 general protection fault in htb_qlen_notify
2025/07/14 13:35 android13-5.15-lts eabc268e4fb2 d8fc7335 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 general protection fault in htb_qlen_notify
* Struck through repros no longer work on HEAD.