syzbot


general protection fault in htb_qlen_notify

Status: auto-obsoleted due to no activity on 2025/10/20 18:07
Bug presence: origin:lts-only
[Documentation on labels]
Reported-by: syzbot+a1df3cc78604c4228e1d@syzkaller.appspotmail.com
First crash: 117d, last: 116d
Fix bisection: failed (error log, bisect log)
  
Bug presence (2)
Date Name Commit Repro Result
2025/07/11 linux-5.15.y (ToT) 2f693b607545 C [report] BUG: unable to handle kernel paging request in htb_qlen_notify
2025/07/11 upstream (ToT) 40f92e79b0aa C Didn't crash
Similar bugs (5)
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 112d 112d 0/2 auto-obsoleted due to no activity on 2025/10/24 10:29
android-6-1 general protection fault in htb_qlen_notify origin:lts 2 C 74 65d 102d 0/2 upstream: reported C repro on 2025/07/26 11:10
android-5-15 general protection fault in htb_qlen_notify 2 13 107d 114d 0/2 auto-obsoleted due to no activity on 2025/09/09 04:18
upstream general protection fault in htb_qlen_notify net 10 C done 166 115d 125d 29/29 fixed on 2025/09/04 16:57
linux-6.1 general protection fault in htb_qlen_notify origin:lts-only 2 C done 4 116d 117d 3/3 fixed on 2025/08/12 17:33
Last patch testing requests (2)
Created Duration User Patch Repo Result
2025/10/20 17:49 16m retest repro linux-5.15.y OK log
2025/07/26 08:03 17m retest repro linux-5.15.y OK log
Fix bisection attempts (2)
Created Duration User Patch Repo Result
2025/08/13 23:43 1m fix candidate upstream error job log
2025/08/11 03:05 0m bisect fix linux-5.15.y error job log

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: 0 PID: 8468 Comm: syz.1.1061 Not tainted 5.15.187-syzkaller #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+0x2d/0xb0 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 c1 49 7a f9 49 8d 9e b0 01 00 00 49 89 dd 49 c1 ed 03 <43> 0f b6 44 25 00 84 c0 75 4a 8b 2b 31 ff 89 ee e8 fe 4c 7a f9 85
RSP: 0018:ffffc9000392ef38 EFLAGS: 00010206
RAX: ffffffff87fd895f RBX: 00000000000001b0 RCX: 0000000000080000
RDX: ffffc900054a1000 RSI: 00000000000002f4 RDI: 00000000000002f5
RBP: 1ffffffff1604bb0 R08: ffff888020ea8000 R09: 0000000000000002
R10: 00000000ffffffff R11: 0000000000000002 R12: dffffc0000000000
R13: 0000000000000036 R14: 0000000000000000 R15: ffff88805e5d2000
FS:  00007fbd3a8906c0(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c3074c7 CR3: 0000000052026000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 qdisc_tree_reduce_backlog+0x25f/0x430 net/sched/sch_api.c:799
 codel_change+0x8d1/0xc00 net/sched/sch_codel.c:183
 codel_init+0x190/0x330 net/sched/sch_codel.c:202
 qdisc_create+0x7bd/0x1170 net/sched/sch_api.c:1260
 tc_modify_qdisc+0xaad/0x16c0 net/sched/sch_api.c:-1
 rtnetlink_rcv_msg+0x9b9/0xe60 net/core/rtnetlink.c:5650
 netlink_rcv_skb+0x1e0/0x430 net/netlink/af_netlink.c:2489
 netlink_unicast_kernel net/netlink/af_netlink.c:1311 [inline]
 netlink_unicast+0x77c/0x920 net/netlink/af_netlink.c:1337
 netlink_sendmsg+0x8ab/0xbc0 net/netlink/af_netlink.c:1905
 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+0x190/0x250 net/socket.c:2526
 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: 0033:0x7fbd3ca28929
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:00007fbd3a890038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007fbd3cc4ffa0 RCX: 00007fbd3ca28929
RDX: 000000000000c010 RSI: 0000200000000280 RDI: 0000000000000003
RBP: 00007fbd3caaab39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fbd3cc4ffa0 R15: 00007ffda32d8fc8
 </TASK>
Modules linked in:
---[ end trace 5ae4290ee3e19a03 ]---
RIP: 0010:htb_deactivate net/sched/sch_htb.c:609 [inline]
RIP: 0010:htb_qlen_notify+0x2d/0xb0 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 c1 49 7a f9 49 8d 9e b0 01 00 00 49 89 dd 49 c1 ed 03 <43> 0f b6 44 25 00 84 c0 75 4a 8b 2b 31 ff 89 ee e8 fe 4c 7a f9 85
RSP: 0018:ffffc9000392ef38 EFLAGS: 00010206
RAX: ffffffff87fd895f RBX: 00000000000001b0 RCX: 0000000000080000
RDX: ffffc900054a1000 RSI: 00000000000002f4 RDI: 00000000000002f5
RBP: 1ffffffff1604bb0 R08: ffff888020ea8000 R09: 0000000000000002
R10: 00000000ffffffff R11: 0000000000000002 R12: dffffc0000000000
R13: 0000000000000036 R14: 0000000000000000 R15: ffff88805e5d2000
FS:  00007fbd3a8906c0(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c3074c7 CR3: 0000000052026000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 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 c1 49 7a f9       	call   0xf97a49dd
  1c:	49 8d 9e b0 01 00 00 	lea    0x1b0(%r14),%rbx
  23:	49 89 dd             	mov    %rbx,%r13
  26:	49 c1 ed 03          	shr    $0x3,%r13
* 2a:	43 0f b6 44 25 00    	movzbl 0x0(%r13,%r12,1),%eax <-- trapping instruction
  30:	84 c0                	test   %al,%al
  32:	75 4a                	jne    0x7e
  34:	8b 2b                	mov    (%rbx),%ebp
  36:	31 ff                	xor    %edi,%edi
  38:	89 ee                	mov    %ebp,%esi
  3a:	e8 fe 4c 7a f9       	call   0xf97a4d3d
  3f:	85                   	.byte 0x85

Crashes (9):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/07/10 22:23 linux-5.15.y 2f693b607545 3cda49cf .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan general protection fault in htb_qlen_notify
2025/07/10 21:34 linux-5.15.y 2f693b607545 3cda49cf .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan general protection fault in htb_qlen_notify
2025/07/10 18:58 linux-5.15.y 2f693b607545 3cda49cf .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan general protection fault in htb_qlen_notify
2025/07/11 03:05 linux-5.15.y 2f693b607545 3cda49cf .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 BUG: unable to handle kernel paging request in htb_qlen_notify
2025/07/11 02:27 linux-5.15.y 2f693b607545 3cda49cf .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 BUG: unable to handle kernel paging request in htb_qlen_notify
2025/07/10 22:21 linux-5.15.y 2f693b607545 3cda49cf .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 BUG: unable to handle kernel paging request in htb_qlen_notify
2025/07/10 21:53 linux-5.15.y 2f693b607545 3cda49cf .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 BUG: unable to handle kernel paging request in htb_qlen_notify
2025/07/10 19:54 linux-5.15.y 2f693b607545 3cda49cf .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 BUG: unable to handle kernel paging request in htb_qlen_notify
2025/07/10 19:54 linux-5.15.y 2f693b607545 3cda49cf .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 BUG: unable to handle kernel paging request in htb_qlen_notify
* Struck through repros no longer work on HEAD.