[syzbot] [bpf?] [net?] KASAN: slab-use-after-free Read in bq_xmit_all

syzbot
2024-07-19T05:12:23Z

Hello,

syzbot found the following issue on:

HEAD commit: 73399b58e5e5 Add linux-next specific files for 20240718
git tree: linux-next
console+strace: https://syzkaller.appspot.com/x/log.txt?x=111f2195980000
kernel config: https://syzkaller.appspot.com/x/.config?x=54e443ddc2b981c8
dashboard link: https://syzkaller.appspot.com/bug?extid=707d98c8649695eaf329
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1602cf31980000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=106fde5e980000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/fbab059c854f/disk-73399b58.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/874a209f4c3f/vmlinux-73399b58.xz
kernel image: https://storage.googleapis.com/syzbot-assets/f34e5c7be278/bzImage-73399b58.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+707d98c8649695eaf329@syzkaller.appspotmail.com

------------[ cut here ]------------
UBSAN: array-index-out-of-bounds in ./kernel/bpf/devmap.c:385:28
index 16 is out of range for type 'struct xdp_frame *[16]'
CPU: 1 UID: 0 PID: 5101 Comm: syz-executor232 Not tainted 6.10.0-next-20240718-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024
Call Trace:
<IRQ>
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
ubsan_epilogue lib/ubsan.c:231 [inline]
__ubsan_handle_out_of_bounds+0x121/0x150 lib/ubsan.c:429
bq_xmit_all+0x157/0x11d0 kernel/bpf/devmap.c:385
__dev_flush+0x81/0x160 kernel/bpf/devmap.c:425
xdp_do_check_flushed+0x129/0x240 net/core/filter.c:4300
__napi_poll+0xe4/0x490 net/core/dev.c:6774
napi_poll net/core/dev.c:6840 [inline]
net_rx_action+0x89b/0x1240 net/core/dev.c:6962
handle_softirqs+0x2c4/0x970 kernel/softirq.c:554
__do_softirq kernel/softirq.c:588 [inline]
invoke_softirq kernel/softirq.c:428 [inline]
__irq_exit_rcu+0xf4/0x1c0 kernel/softirq.c:637
irq_exit_rcu+0x9/0x30 kernel/softirq.c:649
common_interrupt+0xaa/0xd0 arch/x86/kernel/irq.c:278
</IRQ>
<TASK>
asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:693
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0xd8/0x140 kernel/locking/spinlock.c:194
Code: 9c 8f 44 24 20 42 80 3c 23 00 74 08 4c 89 f7 e8 ce cf 5c f6 f6 44 24 21 02 75 52 41 f7 c7 00 02 00 00 74 01 fb bf 01 00 00 00 <e8> c3 69 c4 f5 65 8b 05 04 5f 65 74 85 c0 74 43 48 c7 04 24 0e 36
RSP: 0018:ffffc9000369fb60 EFLAGS: 00000206
RAX: 3e45100d05912800 RBX: 1ffff920006d3f70 RCX: ffffffff817023ea
RDX: dffffc0000000000 RSI: ffffffff8bcad5c0 RDI: 0000000000000001
RBP: ffffc9000369fbf0 R08: ffffffff9300f817 R09: 1ffffffff2601f02
R10: dffffc0000000000 R11: fffffbfff2601f03 R12: dffffc0000000000
R13: 1ffff920006d3f6c R14: ffffc9000369fb80 R15: 0000000000000246
spin_unlock_irqrestore include/linux/spinlock.h:406 [inline]
do_notify_parent_cldstop+0x9ab/0xb50 kernel/signal.c:2216
ptrace_stop+0x465/0x940 kernel/signal.c:2319
ptrace_do_notify kernel/signal.c:2393 [inline]
ptrace_notify+0x255/0x380 kernel/signal.c:2405
ptrace_report_syscall include/linux/ptrace.h:415 [inline]
ptrace_report_syscall_entry include/linux/ptrace.h:452 [inline]
syscall_trace_enter+0x5d/0x150 kernel/entry/common.c:45
syscall_enter_from_user_mode_work include/linux/entry-common.h:168 [inline]
syscall_enter_from_user_mode include/linux/entry-common.h:198 [inline]
do_syscall_64+0xcc/0x230 arch/x86/entry/common.c:79
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f708ebe0e20
Code: ff f7 d8 64 89 02 48 c7 c0 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 80 3d 81 e2 07 00 00 74 17 b8 03 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 48 c3 0f 1f 80 00 00 00 00 48 83 ec 18 89 7c
RSP: 002b:00007ffd97b2a878 EFLAGS: 00000202 ORIG_RAX: 0000000000000003
RAX: ffffffffffffffda RBX: 0000000000000015 RCX: 00007f708ebe0e20
RDX: ffffffffffffffb8 RSI: 0000000020000240 RDI: 0000000000000014
RBP: 0000000000000000 R08: 00007ffd97b2a9a8 R09: 00007ffd97b2a9a8
R10: 00007ffd97b2a9a8 R11: 0000000000000202 R12: 0000000000000000
R13: 0000000000000000 R14: 00007ffd97b2a8b0 R15: 00007ffd97b2a8a0
</TASK>
---[ end trace ]---
----------------
Code disassembly (best guess):
0: 9c pushf
1: 8f 44 24 20 pop 0x20(%rsp)
5: 42 80 3c 23 00 cmpb $0x0,(%rbx,%r12,1)
a: 74 08 je 0x14
c: 4c 89 f7 mov %r14,%rdi
f: e8 ce cf 5c f6 call 0xf65ccfe2
14: f6 44 24 21 02 testb $0x2,0x21(%rsp)
19: 75 52 jne 0x6d
1b: 41 f7 c7 00 02 00 00 test $0x200,%r15d
22: 74 01 je 0x25
24: fb sti
25: bf 01 00 00 00 mov $0x1,%edi
* 2a: e8 c3 69 c4 f5 call 0xf5c469f2 <-- trapping instruction
2f: 65 8b 05 04 5f 65 74 mov %gs:0x74655f04(%rip),%eax # 0x74655f3a
36: 85 c0 test %eax,%eax
38: 74 43 je 0x7d
3a: 48 rex.W
3b: c7 .byte 0xc7
3c: 04 24 add $0x24,%al
3e: 0e (bad)
3f: 36 ss

---
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