2023-07-30 01:20:36

by syzbot

[permalink] [raw]
Subject: [syzbot] [bpf?] UBSAN: array-index-out-of-bounds in bpf_mprog_detach

Hello,

syzbot found the following issue on:

HEAD commit: ec87f05402f5 octeontx2-af: Install TC filter rules in hard..
git tree: net-next
console output: https://syzkaller.appspot.com/x/log.txt?x=12a76df1a80000
kernel config: https://syzkaller.appspot.com/x/.config?x=8acaeb93ad7c6aaa
dashboard link: https://syzkaller.appspot.com/bug?extid=0c06ba0f831fe07a8f27
compiler: gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/0fc53904fc08/disk-ec87f054.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/aee64718ea5c/vmlinux-ec87f054.xz
kernel image: https://storage.googleapis.com/syzbot-assets/d3b6d3f4cfbc/bzImage-ec87f054.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: [email protected]

================================================================================
UBSAN: array-index-out-of-bounds in ./include/linux/bpf_mprog.h:292:24
index 4294967295 is out of range for type 'bpf_mprog_fp [64]'
CPU: 1 PID: 13232 Comm: syz-executor.1 Not tainted 6.5.0-rc2-syzkaller-00573-gec87f05402f5 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2023
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x125/0x1b0 lib/dump_stack.c:106
ubsan_epilogue lib/ubsan.c:217 [inline]
__ubsan_handle_out_of_bounds+0x111/0x150 lib/ubsan.c:348
bpf_mprog_read include/linux/bpf_mprog.h:292 [inline]
bpf_mprog_fetch kernel/bpf/mprog.c:307 [inline]
bpf_mprog_detach+0xcd7/0xd50 kernel/bpf/mprog.c:381
tcx_prog_detach+0x258/0x950 kernel/bpf/tcx.c:78
bpf_prog_detach kernel/bpf/syscall.c:3877 [inline]
__sys_bpf+0x36ee/0x4ec0 kernel/bpf/syscall.c:5357
__do_sys_bpf kernel/bpf/syscall.c:5449 [inline]
__se_sys_bpf kernel/bpf/syscall.c:5447 [inline]
__x64_sys_bpf+0x78/0xc0 kernel/bpf/syscall.c:5447
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x38/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f443e27cb29
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f443cdfe0c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000141
RAX: ffffffffffffffda RBX: 00007f443e39bf80 RCX: 00007f443e27cb29
RDX: 0000000000000020 RSI: 0000000020000340 RDI: 0000000000000009
RBP: 00007f443e2c847a R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007f443e39bf80 R15: 00007ffdb0833788
</TASK>
================================================================================


---
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2023-08-04 01:02:34

by Martin KaFai Lau

[permalink] [raw]
Subject: Re: [syzbot] [bpf?] UBSAN: array-index-out-of-bounds in bpf_mprog_detach

On 7/29/23 5:48 PM, syzbot wrote:
> syzbot found the following issue on:
>
> HEAD commit: ec87f05402f5 octeontx2-af: Install TC filter rules in hard..
> git tree: net-next
> console output:https://syzkaller.appspot.com/x/log.txt?x=12a76df1a80000
> kernel config:https://syzkaller.appspot.com/x/.config?x=8acaeb93ad7c6aaa
> dashboard link:https://syzkaller.appspot.com/bug?extid=0c06ba0f831fe07a8f27
> compiler: gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
>
> Unfortunately, I don't have any reproducer for this issue yet.
>
> Downloadable assets:
> disk image:https://storage.googleapis.com/syzbot-assets/0fc53904fc08/disk-ec87f054.raw.xz
> vmlinux:https://storage.googleapis.com/syzbot-assets/aee64718ea5c/vmlinux-ec87f054.xz
> kernel image:https://storage.googleapis.com/syzbot-assets/d3b6d3f4cfbc/bzImage-ec87f054.xz
>
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by:[email protected]
>
> ================================================================================
> UBSAN: array-index-out-of-bounds in ./include/linux/bpf_mprog.h:292:24
> index 4294967295 is out of range for type 'bpf_mprog_fp [64]'
> CPU: 1 PID: 13232 Comm: syz-executor.1 Not tainted 6.5.0-rc2-syzkaller-00573-gec87f05402f5 #0
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2023
> Call Trace:
> <TASK>
> __dump_stack lib/dump_stack.c:88 [inline]
> dump_stack_lvl+0x125/0x1b0 lib/dump_stack.c:106
> ubsan_epilogue lib/ubsan.c:217 [inline]
> __ubsan_handle_out_of_bounds+0x111/0x150 lib/ubsan.c:348
> bpf_mprog_read include/linux/bpf_mprog.h:292 [inline]
> bpf_mprog_fetch kernel/bpf/mprog.c:307 [inline]
> bpf_mprog_detach+0xcd7/0xd50 kernel/bpf/mprog.c:381
> tcx_prog_detach+0x258/0x950 kernel/bpf/tcx.c:78
> bpf_prog_detach kernel/bpf/syscall.c:3877 [inline]
> __sys_bpf+0x36ee/0x4ec0 kernel/bpf/syscall.c:5357

Thanks for the report. I will take a look.

2023-08-04 13:35:42

by Daniel Borkmann

[permalink] [raw]
Subject: Re: [syzbot] [bpf?] UBSAN: array-index-out-of-bounds in bpf_mprog_detach

On 8/4/23 1:39 AM, Martin KaFai Lau wrote:
> On 7/29/23 5:48 PM, syzbot wrote:
>> syzbot found the following issue on:
>>
>> HEAD commit:    ec87f05402f5 octeontx2-af: Install TC filter rules in hard..
>> git tree:       net-next
>> console output:https://syzkaller.appspot.com/x/log.txt?x=12a76df1a80000
>> kernel config:https://syzkaller.appspot.com/x/.config?x=8acaeb93ad7c6aaa
>> dashboard link:https://syzkaller.appspot.com/bug?extid=0c06ba0f831fe07a8f27
>> compiler:       gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
>>
>> Unfortunately, I don't have any reproducer for this issue yet.
>>
>> Downloadable assets:
>> disk image:https://storage.googleapis.com/syzbot-assets/0fc53904fc08/disk-ec87f054.raw.xz
>> vmlinux:https://storage.googleapis.com/syzbot-assets/aee64718ea5c/vmlinux-ec87f054.xz
>> kernel image:https://storage.googleapis.com/syzbot-assets/d3b6d3f4cfbc/bzImage-ec87f054.xz
>>
>> IMPORTANT: if you fix the issue, please add the following tag to the commit:
>> Reported-by:[email protected]
>>
>> ================================================================================
>> UBSAN: array-index-out-of-bounds in ./include/linux/bpf_mprog.h:292:24
>> index 4294967295 is out of range for type 'bpf_mprog_fp [64]'
>> CPU: 1 PID: 13232 Comm: syz-executor.1 Not tainted 6.5.0-rc2-syzkaller-00573-gec87f05402f5 #0
>> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2023
>> Call Trace:
>>   <TASK>
>>   __dump_stack lib/dump_stack.c:88 [inline]
>>   dump_stack_lvl+0x125/0x1b0 lib/dump_stack.c:106
>>   ubsan_epilogue lib/ubsan.c:217 [inline]
>>   __ubsan_handle_out_of_bounds+0x111/0x150 lib/ubsan.c:348
>>   bpf_mprog_read include/linux/bpf_mprog.h:292 [inline]
>>   bpf_mprog_fetch kernel/bpf/mprog.c:307 [inline]
>>   bpf_mprog_detach+0xcd7/0xd50 kernel/bpf/mprog.c:381
>>   tcx_prog_detach+0x258/0x950 kernel/bpf/tcx.c:78
>>   bpf_prog_detach kernel/bpf/syscall.c:3877 [inline]
>>   __sys_bpf+0x36ee/0x4ec0 kernel/bpf/syscall.c:5357

Was able to repro, fix + selftest is here:
https://lore.kernel.org/bpf/[email protected]/

Thanks,
Daniel