Hello,
syzbot found the following issue on:
HEAD commit: dfc486ec9cce Linux 6.1.144
git tree: linux-6.1.y
console output:
https://syzkaller.appspot.com/x/log.txt?x=126f9bd4580000
kernel config:
https://syzkaller.appspot.com/x/.config?x=f8c435072b93fddd
dashboard link:
https://syzkaller.appspot.com/bug?extid=ce3896e859e1057a1449
compiler: Debian clang version 20.1.7 (++20250616065708+6146a88f6049-1~exp1~20250616065826.132), Debian LLD 20.1.7
userspace arch: arm64
Unfortunately, I don't have any reproducer for this issue yet.
Downloadable assets:
disk image:
https://storage.googleapis.com/syzbot-assets/be2756a32e51/disk-dfc486ec.raw.xz
vmlinux:
https://storage.googleapis.com/syzbot-assets/fb99deb14858/vmlinux-dfc486ec.xz
kernel image:
https://storage.googleapis.com/syzbot-assets/c651d3cff1de/Image-dfc486ec.gz.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by:
syzbot+ce3896...@syzkaller.appspotmail.com
tipc: Enabling of bearer <eth:syzkaller0> rejected, already enabled
Unable to handle kernel paging request at virtual address dfff800000000004
KASAN: null-ptr-deref in range [0x0000000000000020-0x0000000000000027]
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
[dfff800000000004] address between user and kernel address ranges
Internal error: Oops: 0000000096000006 [#1] PREEMPT SMP
Modules linked in:
CPU: 0 PID: 9893 Comm: syz.0.1490 Not tainted 6.1.144-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 : qdisc_tree_reduce_backlog+0x1e8/0x410 net/sched/sch_api.c:802
lr : qdisc_tree_reduce_backlog+0x19c/0x410 net/sched/sch_api.c:794
sp : ffff800022496da0
x29: ffff800022496da0 x28: 0000000000000004 x27: dfff800000000000
x26: 0000000000000000 x25: 0000000000000000 x24: 0000000000000020
x23: 00000000000b0002 x22: ffff80001775e5e0 x21: ffff0000f5dda000
x20: 0000000000000000 x19: 0000000000000000 x18: 00000000bc62ff92
x17: dfff800000000000 x16: ffff8000082d0f50 x15: 0000000000000002
x14: 00000000ffffffff x13: 0000000000ff0100 x12: 0000000000ff0100
x11: ff0080000febb728 x10: 0000000000000002 x9 : ffff0000cdc78000
x8 : 0000000000000000 x7 : ffff80000febbedc x6 : 0000000000000000
x5 : 0000000000000000 x4 : 0000000000000000 x3 : 0000000000000002
x2 : 0000000000000008 x1 : 0000000000000000 x0 : 0000000000000000
Call trace:
qdisc_tree_reduce_backlog+0x1e8/0x410 net/sched/sch_api.c:802
hhf_change+0x6c4/0xbb8 net/sched/sch_hhf.c:567
hhf_init+0x1b0/0x6fc net/sched/sch_hhf.c:593
qdisc_create+0x6f0/0xe20 net/sched/sch_api.c:1310
tc_modify_qdisc+0x954/0x1718 net/sched/sch_api.c:-1
rtnetlink_rcv_msg+0x734/0xce4 net/core/rtnetlink.c:6153
netlink_rcv_skb+0x208/0x3c4 net/netlink/af_netlink.c:2493
rtnetlink_rcv+0x28/0x38 net/core/rtnetlink.c:6171
netlink_unicast_kernel net/netlink/af_netlink.c:1311 [inline]
netlink_unicast+0x600/0x818 net/netlink/af_netlink.c:1337
netlink_sendmsg+0x6e8/0x9b0 net/netlink/af_netlink.c:1859
sock_sendmsg_nosec net/socket.c:718 [inline]
__sock_sendmsg net/socket.c:730 [inline]
____sys_sendmsg+0x5b8/0x918 net/socket.c:2519
___sys_sendmsg net/socket.c:2573 [inline]
__sys_sendmsg+0x25c/0x320 net/socket.c:2602
__do_sys_sendmsg net/socket.c:2611 [inline]
__se_sys_sendmsg net/socket.c:2609 [inline]
__arm64_sys_sendmsg+0x80/0x94 net/socket.c:2609
__invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
invoke_syscall+0x98/0x2bc arch/arm64/kernel/syscall.c:52
el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:140
do_el0_svc+0x58/0x13c arch/arm64/kernel/syscall.c:204
el0_svc+0x58/0x138 arch/arm64/kernel/entry-common.c:637
el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585
Code: 14000020 f9400339 91008338 d343ff1c (387b6b88)
---[ end trace 0000000000000000 ]---
pstore: crypto_comp_compress failed, ret = -22!
----------------
Code disassembly (best guess):
0: 14000020 b 0x80
4: f9400339 ldr x25, [x25]
8: 91008338 add x24, x25, #0x20
c: d343ff1c lsr x28, x24, #3
* 10: 387b6b88 ldrb w8, [x28, x27] <-- trapping instruction
---
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