Re: [PATCH v3 6/6] 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:
- [High] Missing O_NONBLOCK in open() can cause indefinite hangs on untrusted paths.
--

commit febe76c541fd0ae3fbecd6102991f4418485f2b8
Author: Ian Rogers <irogers@google.com>

perf debuginfo: Fix libdw API contract violations

This commit adds a return value check for dwfl_report_end() during offline
initialization and validates the result of dwfl_module_relocation_info()
before passing it to strcmp().

> diff --git a/tools/perf/util/debuginfo.c b/tools/perf/util/debuginfo.c
> index 0e35c13abd04..49cb7f9b715d 100644
> --- a/tools/perf/util/debuginfo.c
> +++ b/tools/perf/util/debuginfo.c
> @@ -62,7 +62,8 @@ static int debuginfo__init_offline_dwarf(struct debuginfo *dbg,
>  
>  	dwfl_module_build_id(dbg->mod, &dbg->build_id, &dummy);
>  

While reviewing this function, I noticed an older issue that pre-dates this
commit. Does the open() call earlier in this function risk an indefinite hang
if the path refers to a FIFO, device node, or slow network mount?

tools/perf/util/debuginfo.c:debuginfo__init_offline_dwarf() {
        ...
        int fd;

        fd = open(path, O_RDONLY);
        if (fd < 0)
                return fd;
        ...
}

Could this path be opened with the O_NONBLOCK flag to prevent hanging on
untrusted special files?

> -	dwfl_report_end(dbg->dwfl, NULL, NULL);
> +	if (dwfl_report_end(dbg->dwfl, NULL, NULL) != 0)
> +		goto error;
>  
>  	return 0;

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260503003552.1063540-1-irogers@google.com?part=6