Re: [PATCH bpf-next v3] bpf: Clamp trace length in __bpf_get_stack to fix OOB write

[Brahmajit Das]

On 12.11.2025 08:40, 'Lecomte, Arnaud' via syzkaller-bugs wrote:
> I am a not sure this is the right solution and I am scared that by
> forcing this clamping, we are hiding something else.
> If we have a look at the code below:
> ```
> 
> |
> 
> 	if (trace_in) {
> 		trace = trace_in;
> 		trace->nr = min_t(u32, trace->nr, max_depth);
> 	} else if (kernel && task) {
> 		trace = get_callchain_entry_for_task(task, max_depth);
> 	} else {
> 		trace = get_perf_callchain(regs, kernel, user, max_depth,
> 					crosstask, false, 0);
> 	} ``` trace should be (if I remember correctly) clamped there. If not, it
> might hide something else. I would like to have a look at the return for
> each if case through gdb. |

Sure, I can do that.

> 
> Thanks,
> Arnaud

-- 
Regards,
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