[syzbot] [net?] UBSAN: array-index-out-of-bounds in cake_enqueue (2)

[syzbot <syzbot+f63600d288bfb7057424@syzkaller.appspotmail.com>]

Hello,

syzbot found the following issue on:

HEAD commit:    573067a5a685 Merge branch 'for-next/core' into for-kernelci
git tree:       git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci
console output: https://syzkaller.appspot.com/x/log.txt?x=17556f30580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=cd7202b56d469648
dashboard link: https://syzkaller.appspot.com/bug?extid=f63600d288bfb7057424
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
userspace arch: arm64

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/9d3b5c855aa0/disk-573067a5.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/0c06fc1ead83/vmlinux-573067a5.xz
kernel image: https://storage.googleapis.com/syzbot-assets/3390e59b9e4b/Image-573067a5.gz.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+f63600d288bfb7057424@syzkaller.appspotmail.com

------------[ cut here ]------------
UBSAN: array-index-out-of-bounds in net/sched/sch_cake.c:1862:6
index 65535 is out of range for type 'u16[1025]' (aka 'unsigned short[1025]')
CPU: 1 UID: 0 PID: 8219 Comm: syz.0.325 Not tainted 6.13.0-rc3-syzkaller-g573067a5a685 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Call trace:
 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:466 (C)
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0xe4/0x150 lib/dump_stack.c:120
 dump_stack+0x1c/0x28 lib/dump_stack.c:129
 ubsan_epilogue lib/ubsan.c:231 [inline]
 __ubsan_handle_out_of_bounds+0xf8/0x148 lib/ubsan.c:429
 cake_enqueue+0x6000/0x78d4 net/sched/sch_cake.c:1862
 dev_qdisc_enqueue+0x60/0x374 net/core/dev.c:3793
 __dev_xmit_skb net/core/dev.c:3889 [inline]
 __dev_queue_xmit+0xbe4/0x35b4 net/core/dev.c:4400
 dev_queue_xmit include/linux/netdevice.h:3168 [inline]
 packet_xmit+0x6c/0x318 net/packet/af_packet.c:276
 packet_snd net/packet/af_packet.c:3146 [inline]
 packet_sendmsg+0x3ca8/0x52fc net/packet/af_packet.c:3178
 sock_sendmsg_nosec net/socket.c:711 [inline]
 __sock_sendmsg net/socket.c:726 [inline]
 __sys_sendto+0x360/0x4d8 net/socket.c:2197
 __do_sys_sendto net/socket.c:2204 [inline]
 __se_sys_sendto net/socket.c:2200 [inline]
 __arm64_sys_sendto+0xd8/0xf8 net/socket.c:2200
 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
 invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:49
 el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132
 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151
 el0_svc+0x54/0x168 arch/arm64/kernel/entry-common.c:744
 el0t_64_sync_handler+0x84/0x108 arch/arm64/kernel/entry-common.c:762
 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:600
---[ end trace ]---
FAULT_INJECTION: forcing a failure.
name fail_usercopy, interval 1, probability 0, space 0, times 0
CPU: 1 UID: 0 PID: 8219 Comm: syz.0.325 Not tainted 6.13.0-rc3-syzkaller-g573067a5a685 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Call trace:
 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:466 (C)
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0xe4/0x150 lib/dump_stack.c:120
 dump_stack+0x1c/0x28 lib/dump_stack.c:129
 fail_dump lib/fault-inject.c:53 [inline]
 should_fail_ex+0x3b0/0x50c lib/fault-inject.c:154
 should_fail+0x14/0x24 lib/fault-inject.c:164
 should_fail_usercopy+0x20/0x30 lib/fault-inject-usercopy.c:37
 _inline_copy_to_user include/linux/uaccess.h:193 [inline]
 copy_to_user include/linux/uaccess.h:223 [inline]
 simple_read_from_buffer+0xd4/0x248 fs/libfs.c:1128
 proc_fail_nth_read+0x134/0x1a0 fs/proc/base.c:1482
 vfs_read+0x22c/0x970 fs/read_write.c:563
 ksys_read+0x15c/0x26c fs/read_write.c:708
 __do_sys_read fs/read_write.c:717 [inline]
 __se_sys_read fs/read_write.c:715 [inline]
 __arm64_sys_read+0x7c/0x90 fs/read_write.c:715
 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
 invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:49
 el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132
 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151
 el0_svc+0x54/0x168 arch/arm64/kernel/entry-common.c:744
 el0t_64_sync_handler+0x84/0x108 arch/arm64/kernel/entry-common.c:762
 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:600


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