Re: [PATCH bpf-next v4 2/2] bpf: fix stackmap overflow check in __bpf_get_stackid()

[Yonghong Song <yonghong.song@linux.dev>]

On 8/18/25 9:57 AM, Yonghong Song wrote:
>
>
> On 8/18/25 6:49 AM, Lecomte, Arnaud wrote:
>> Hey,
>> Just forwarding the patch to the associated maintainers with 
>> `stackmap.c`.
>
> Arnaud, please add Ack (provided in comments for v3) to make things 
> easier
> for maintainers.
>
> Also, looks like all your patch sets (v1 to v4) in the same thread.

sorry, it should be v3 and v4 in the same thread.

> It would be good to have all these versions in separate thread.
> Please look at some examples in bpf mailing list.
>
>> Have a great day,
>> Cheers
>>
>> On 13/08/2025 21:55, Arnaud Lecomte wrote:
>>> Syzkaller reported a KASAN slab-out-of-bounds write in 
>>> __bpf_get_stackid()
>>> when copying stack trace data. The issue occurs when the perf trace
>>>   contains more stack entries than the stack map bucket can hold,
>>>   leading to an out-of-bounds write in the bucket's data array.
>>>
>>> Changes in v2:
>>>   - Fixed max_depth names across get stack id
>>>
>>> Changes in v4:
>>>   - Removed unnecessary empty line in __bpf_get_stackid
>>>
>>> Reported-by: syzbot+c9b724fbb41cf2538b7b@syzkaller.appspotmail.com
>>> Closes: https://syzkaller.appspot.com/bug?extid=c9b724fbb41cf2538b7b
>>> Signed-off-by: Arnaud Lecomte <contact@arnaud-lcm.com>
>>> ---
>>>   kernel/bpf/stackmap.c | 23 +++++++++++++----------
>>>   1 file changed, 13 insertions(+), 10 deletions(-)
>>>
> [...]
>
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