KASAN: slab-out-of-bounds Read in taprio_dequeue_from_txq

From: Palash Oswal
Date: Thu Apr 13 2023 - 00:38:36 EST

Hello,
I found the following issue using syzkaller with enriched corpus on:
HEAD commit : 0bcc4025550403ae28d2984bddacafbca0a2f112
git tree: linux

C Reproducer : I do not have a C reproducer yet. I will update this
thread when I get one.
Kernel .config :
https://gist.github.com/oswalpalash/d9580b0bfce202b37445fa5fd426e41f

Console log :
==================================================================
BUG: KASAN: slab-out-of-bounds in taprio_dequeue_from_txq+0x7e3/0x8e0
Read of size 8 at addr ffff888110ad3380 by task syz-executor.1/18757

CPU: 1 PID: 18757 Comm: syz-executor.1 Not tainted
6.3.0-rc6-pasta-00035-g0bcc40255504 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
1.13.0-1ubuntu1.1 04/01/2014
Call Trace:
<IRQ>
dump_stack_lvl+0xd9/0x150
print_address_description.constprop.0+0x2c/0x3c0
kasan_report+0x11c/0x130
taprio_dequeue_from_txq+0x7e3/0x8e0
taprio_dequeue_tc_priority+0x272/0x440
taprio_dequeue+0x12c/0x5e0
__qdisc_run+0x1b2/0x1620
net_tx_action+0x6e3/0xc20
__do_softirq+0x1d4/0x905
__irq_exit_rcu+0x114/0x190
irq_exit_rcu+0x9/0x20
sysvec_apic_timer_interrupt+0x97/0xc0
</IRQ>
<TASK>
asm_sysvec_apic_timer_interrupt+0x1a/0x20
RIP: 0010:__sanitizer_cov_trace_pc+0xb/0x70
Code: 0f 1e fa 48 8b be a8 01 00 00 e8 b0 ff ff ff 31 c0 c3 66 66 2e
0f 1f 84 00 00 00 00 00 66 90 f3 0f 1e fa 65 8b 05 fd c2 81 7e <89> c1
48 8b 34 24 81 e1 00 01 00 00 65 48 8b 14 25 c0 b8 03 00 a9
RSP: 0018:ffffc9000308fbf0 EFLAGS: 00000246
RAX: 0000000080000000 RBX: 000000000080ce08 RCX: ffffffff81713a44
RDX: ffff88811187e340 RSI: 0000000000000000 RDI: 0000000000000005
RBP: ffff888135c2b880 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: ffffc9000308fd98 R14: dffffc0000000000 R15: ffff88811187e340
hrtimer_active+0xda/0x1f0
hrtimer_try_to_cancel+0x25/0x4b0
do_nanosleep+0x161/0x4f0
hrtimer_nanosleep+0x19b/0x430
common_nsleep+0xa6/0xd0
__x64_sys_clock_nanosleep+0x32e/0x480
do_syscall_64+0x39/0xb0
entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f5750abbe1f
Code: 44 00 00 b8 16 00 00 00 eb b2 90 89 7c 24 08 e8 77 e1 ff ff 8b
7c 24 08 4d 89 ea 4c 89 e2 41 89 c0 89 ee b8 e6 00 00 00 0f 05 <44> 89
c7 48 89 44 24 08 e8 b4 e1 ff ff 48 8b 44 24 08 e9 5e ff ff
RSP: 002b:00007ffc798ee300 EFLAGS: 00000293 ORIG_RAX: 00000000000000e6
RAX: ffffffffffffffda RBX: 0000000000000e01 RCX: 00007f5750abbe1f
RDX: 00007ffc798ee380 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 00007ffc79957080
R10: 0000000000000000 R11: 0000000000000293 R12: 00007ffc798ee380
R13: 0000000000000000 R14: 00007ffc798ee3fc R15: 0000000000000032
</TASK>

Allocated by task 10073:
kasan_save_stack+0x22/0x40
kasan_set_track+0x25/0x30
__kasan_kmalloc+0xa3/0xb0
__kmalloc+0x5e/0x190
taprio_init+0x319/0x8c0
qdisc_create+0x4d1/0x1040
tc_modify_qdisc+0x488/0x1a40
rtnetlink_rcv_msg+0x43d/0xd50
netlink_rcv_skb+0x165/0x440
netlink_unicast+0x547/0x7f0
netlink_sendmsg+0x926/0xe30
sock_sendmsg+0xde/0x190
____sys_sendmsg+0x71c/0x900
___sys_sendmsg+0x110/0x1b0
__sys_sendmsg+0xf7/0x1c0
do_syscall_64+0x39/0xb0
entry_SYSCALL_64_after_hwframe+0x63/0xcd

The buggy address belongs to the object at ffff888110ad3300
which belongs to the cache kmalloc-128 of size 128
The buggy address is located 0 bytes to the right of
allocated 128-byte region [ffff888110ad3300, ffff888110ad3380)

The buggy address belongs to the physical page:
page:ffffea000442b4c0 refcount:1 mapcount:0 mapping:0000000000000000
index:0x0 pfn:0x110ad3
flags: 0x57ff00000000200(slab|node=1|zone=2|lastcpupid=0x7ff)
raw: 057ff00000000200 ffff888012440400 ffffea0004432050 ffffea0004d34490
raw: 0000000000000000 ffff888110ad3000 0000000100000010 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask
0x242020(__GFP_HIGH|__GFP_NOWARN|__GFP_COMP|__GFP_THISNODE), pid
10056, tgid 10053 (syz-executor.0), ts 1299225545953, free_ts
1297773239495
get_page_from_freelist+0x1190/0x2e20
__alloc_pages+0x1cb/0x4a0
cache_grow_begin+0x9b/0x3b0
cache_alloc_refill+0x27f/0x380
__kmem_cache_alloc_node+0x360/0x3f0
kmalloc_trace+0x26/0xe0
__hw_addr_add_ex+0x22d/0x7f0
dev_addr_init+0x13e/0x220
alloc_netdev_mqs+0x2f8/0x1250
rtnl_create_link+0xbeb/0xee0
__rtnl_newlink+0xfd2/0x1840
rtnl_newlink+0x68/0xa0
rtnetlink_rcv_msg+0x43d/0xd50
netlink_rcv_skb+0x165/0x440
netlink_unicast+0x547/0x7f0
netlink_sendmsg+0x926/0xe30
page last free stack trace:
free_pcp_prepare+0x5d5/0xa50
free_unref_page+0x1d/0x490
slabs_destroy+0x85/0xc0
___cache_free+0x204/0x3d0
qlist_free_all+0x4f/0x1a0
kasan_quarantine_reduce+0x192/0x220
__kasan_slab_alloc+0x63/0x90
kmem_cache_alloc+0x1bd/0x3f0
__alloc_file+0x21/0x270
alloc_empty_file+0x71/0x190
alloc_file+0x5e/0x800
alloc_file_pseudo+0x169/0x250
sock_alloc_file+0x53/0x190
__sys_socket+0x1a8/0x250
__x64_sys_socket+0x73/0xb0
do_syscall_64+0x39/0xb0

Memory state around the buggy address:
ffff888110ad3280: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff888110ad3300: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff888110ad3380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
^
ffff888110ad3400: 00 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc
ffff888110ad3480: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================
----------------
Code disassembly (best guess):
0: 0f 1e fa nop %edx
3: 48 8b be a8 01 00 00 mov 0x1a8(%rsi),%rdi
a: e8 b0 ff ff ff callq 0xffffffbf
f: 31 c0 xor %eax,%eax
11: c3 retq
12: 66 66 2e 0f 1f 84 00 data16 nopw %cs:0x0(%rax,%rax,1)
19: 00 00 00 00
1d: 66 90 xchg %ax,%ax
1f: f3 0f 1e fa endbr64
23: 65 8b 05 fd c2 81 7e mov %gs:0x7e81c2fd(%rip),%eax
# 0x7e81c327
* 2a: 89 c1 mov %eax,%ecx <-- trapping instruction
2c: 48 8b 34 24 mov (%rsp),%rsi
30: 81 e1 00 01 00 00 and $0x100,%ecx
36: 65 48 8b 14 25 c0 b8 mov %gs:0x3b8c0,%rdx
3d: 03 00
3f: a9 .byte 0xa9