Re: [PATCH v5 9/9] perf debuginfo: Fix libdw API contract violations

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Critical] This problem wasn't introduced by this patch, but the open() call in debuginfo__init_offline_dwarf() lacks the O_NONBLOCK flag, exposing a local Denial of Service (DoS) vulnerability.
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commit a6e339ae66465b909762a437f958cdaed424b666
Author: Ian Rogers <irogers@google.com>

perf debuginfo: Fix libdw API contract violations

This commit adds return value checks for dwfl_report_end and
dwfl_module_relocation_info to prevent potential segmentation faults. It also
fixes a file descriptor leak in the error path of
debuginfo__init_offline_dwarf() when offline initialization fails.

> diff --git a/tools/perf/util/debuginfo.c b/tools/perf/util/debuginfo.c
> index 0e35c13abd04..84a78b30ceac 100644
> --- a/tools/perf/util/debuginfo.c
> +++ b/tools/perf/util/debuginfo.c
> @@ -42,6 +42,7 @@ static int debuginfo__init_offline_dwarf(struct debuginfo *dbg,
>  {
>  	GElf_Addr dummy;
>  	int fd;
> +	bool fd_consumed = false;
>  
>  	fd = open(path, O_RDONLY);

While this wasn't introduced by this patch, could this open() call cause a
regression by hanging on a FIFO?

If the path originates from user-controlled sources, opening it without
O_NONBLOCK can cause the perf record session to hang indefinitely. Using
O_RDONLY | O_NONBLOCK would prevent this.

[ ... ]

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Sashiko AI review · https://sashiko.dev/#/patchset/20260504081227.2203848-1-irogers@google.com?part=9