syzbot

Unable to handle kernel paging request at virtual address dfff80000000000b
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
[dfff80000000000b] address between user and kernel address ranges
Internal error: Oops: 0000000096000006 [#1] PREEMPT SMP
Modules linked in:
CPU: 0 PID: 4291 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 : __list_del_entry_valid+0x28/0x150 lib/list_debug.c:46
lr : __list_del_entry include/linux/list.h:132 [inline]
lr : list_del include/linux/list.h:146 [inline]
lr : drr_qlen_notify+0x38/0x110 net/sched/sch_drr.c:238
sp : ffff80001f486ca0
x29: ffff80001f486ca0 x28: 1ffff000025a914c x27: dfff800000000000
x26: 0000000000000000 x25: ffff800012d48a68 x24: ffff800012d48a60
x23: dfff800000000000 x22: ffff8000162edce0 x21: dfff800000000000
x20: 0000000000000050 x19: 0000000000000050 x18: 0000000000000201
x17: 0000000000000000 x16: ffff8000082bf708 x15: 00000000ffffffff
x14: 0000000000ff0100 x13: ffffffffffffffff x12: 0000000000ff0100
x11: 0000000000000201 x10: 0000000000000000 x9 : ffff80000f98d928
x8 : 000000000000000b x7 : ffff80000f8d3b08 x6 : 0000000000000000
x5 : 0000000000000000 x4 : 0000000000000000 x3 : 0000000000000002
x2 : 0000000000000008 x1 : 0000000000000000 x0 : 0000000000000058
Call trace:
 __list_del_entry_valid+0x28/0x150 lib/list_debug.c:46
 __list_del_entry include/linux/list.h:132 [inline]
 list_del include/linux/list.h:146 [inline]
 drr_qlen_notify+0x38/0x110 net/sched/sch_drr.c:238
 qdisc_tree_reduce_backlog+0x250/0x410 net/sched/sch_api.c:799
 fq_change+0xac0/0xff4 net/sched/sch_fq.c:915
 fq_init+0x2e4/0x4ac net/sched/sch_fq.c:963
 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: 91002000 d2d00015 d343fc08 f2fbfff5 (38756908) 
---[ end trace 42b41fcb0d63ef1e ]---
----------------
Code disassembly (best guess):
   0:	91002000 	add	x0, x0, #0x8
   4:	d2d00015 	mov	x21, #0x800000000000        	// #140737488355328
   8:	d343fc08 	lsr	x8, x0, #3
   c:	f2fbfff5 	movk	x21, #0xdfff, lsl #48
* 10:	38756908 	ldrb	w8, [x8, x21] <-- trapping instruction