syzbot


general protection fault in htb_qlen_notify

Status: upstream: reported C repro on 2025/07/10 18:58
Bug presence: origin:lts-only
[Documentation on labels]
Reported-by: syzbot+a1df3cc78604c4228e1d@syzkaller.appspotmail.com
First crash: 16d, last: 15d
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 10d 10d 0/2 upstream: reported on 2025/07/16 10:29
android-6-1 general protection fault in htb_qlen_notify origin:lts 2 C 4 19h11m 19h20m 0/2 upstream: reported C repro on 2025/07/26 11:10
android-5-15 general protection fault in htb_qlen_notify 2 13 6d02h 12d 0/2 premoderation: reported on 2025/07/14 13:36
upstream general protection fault in htb_qlen_notify net 10 C done 166 14d 23d 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 14d 16d 0/3 upstream: reported C repro on 2025/07/10 18:56
Last patch testing requests (1)
Created Duration User Patch Repo Result
2025/07/26 08:03 17m retest repro linux-5.15.y OK log

Sample crash report:
netlink: 4 bytes leftover after parsing attributes in process `syz.0.16'.
Unable to handle kernel paging request at virtual address dfff800000000036
Mem abort info:
  ESR = 0x0000000096000006
  EC = 0x25: DABT (current EL), IL = 32 bits
  SET = 0, FnV = 0
  EA = 0, S1PTW = 0
  FSC = 0x06: level 2 translation fault
Data abort info:
  ISV = 0, ISS = 0x00000006
  CM = 0, WnR = 0
[dfff800000000036] address between user and kernel address ranges
Internal error: Oops: 0000000096000006 [#1] PREEMPT SMP
Modules linked in:
CPU: 1 PID: 4264 Comm: syz.0.16 Not tainted 5.15.187-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
pstate: 80400005 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : htb_deactivate net/sched/sch_htb.c:609 [inline]
pc : htb_qlen_notify+0x3c/0xc8 net/sched/sch_htb.c:1507
lr : htb_qlen_notify+0x2c/0xc8 net/sched/sch_htb.c:1504
sp : ffff80001fd86da0
x29: ffff80001fd86da0 x28: 1ffff000025a8aa8 x27: dfff800000000000
x26: 0000000000000000 x25: ffff800012d45548 x24: 0000000000000036
x23: dfff800000000000 x22: ffff8000162edce0 x21: ffff0000c0a9e000
x20: 0000000000000000 x19: 00000000000001b0 x18: 0000000000000201
x17: 0000000000000000 x16: ffff8000082bf708 x15: 00000000ffffffff
x14: 0000000000ff0100 x13: ffffffffffffffff x12: 0000000000ff0100
x11: 0000000000000201 x10: 0000000000000000 x9 : 0000000000000003
x8 : ffff0000d9571b40 x7 : ffff80000f8d3b08 x6 : 0000000000000000
x5 : 0000000000000000 x4 : 0000000000000000 x3 : 0000000000000002
x2 : 0000000000000008 x1 : 0000000000000000 x0 : ffff0000c0a9e000
Call trace:
 htb_deactivate net/sched/sch_htb.c:609 [inline]
 htb_qlen_notify+0x3c/0xc8 net/sched/sch_htb.c:1507
 qdisc_tree_reduce_backlog+0x250/0x410 net/sched/sch_api.c:799
 sfq_change net/sched/sch_sfq.c:737 [inline]
 sfq_init+0x1338/0x1da4 net/sched/sch_sfq.c:801
 qdisc_create+0x6e4/0xf24 net/sched/sch_api.c:1260
 tc_modify_qdisc+0x8bc/0x1308 net/sched/sch_api.c:-1
 rtnetlink_rcv_msg+0x9d4/0xd04 net/core/rtnetlink.c:5650
 netlink_rcv_skb+0x208/0x3c4 net/netlink/af_netlink.c:2489
 rtnetlink_rcv+0x28/0x38 net/core/rtnetlink.c:5668
 netlink_unicast_kernel net/netlink/af_netlink.c:1311 [inline]
 netlink_unicast+0x60c/0x89c net/netlink/af_netlink.c:1337
 netlink_sendmsg+0x6e8/0x9cc net/netlink/af_netlink.c:1905
 sock_sendmsg_nosec net/socket.c:704 [inline]
 __sock_sendmsg net/socket.c:716 [inline]
 ____sys_sendmsg+0x61c/0x920 net/socket.c:2436
 ___sys_sendmsg+0x1d0/0x240 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]
 __arm64_sys_sendmsg+0x1a8/0x254 net/socket.c:2526
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:52
 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
 do_el0_svc+0x58/0x14c arch/arm64/kernel/syscall.c:181
 el0_svc+0x78/0x1e0 arch/arm64/kernel/entry-common.c:608
 el0t_64_sync_handler+0xcc/0xe4 arch/arm64/kernel/entry-common.c:626
 el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584
Code: 9106c293 d343fe78 12000a69 11000d29 (38f76b08) 
---[ end trace 33b67244898786be ]---
----------------
Code disassembly (best guess):
   0:	9106c293 	add	x19, x20, #0x1b0
   4:	d343fe78 	lsr	x24, x19, #3
   8:	12000a69 	and	w9, w19, #0x7
   c:	11000d29 	add	w9, w9, #0x3
* 10:	38f76b08 	ldrsb	w8, [x24, x23] <-- trapping instruction

Crashes (9):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
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
2025/07/10 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 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.