[PATCH 6.1 1015/1191] perf dso: Guard close() against invalid fd in dso__decompress_kmodule_path()

From
Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date
2026-09-12 16:48:17
Also in
linux-patches
Reply to
Greg Kroah-Hartman, 2026-09-12
6.1-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Arnaldo Carvalho de Melo <redacted>

[ Upstream commit 10f452dc2de401be76ae8e7395c9663313df8b53 ]

dso__decompress_kmodule_path() unconditionally calls close(fd) on the
return value of decompress_kmodule().  When decompression fails or the
DSO is not compressed, decompress_kmodule() returns -1.  close(-1)
fails with EBADF and clobbers errno, which callers up the chain
(dso__get_filename → __open_dso) depend on for error propagation.

Guard the close() call with fd >= 0 so only valid file descriptors are
closed.

Fixes: 42b3fa670825 ("perf tools: Introduce dso__decompress_kmodule_{fd,path}")
Reported-by: sashiko-bot <sashiko-bot@kernel.org>
Reviewed-by: Ian Rogers <irogers@google.com>
Assisted-by: Claude:claude-opus-4.6
Signed-off-by: Arnaldo Carvalho de Melo <redacted>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 tools/perf/util/dso.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/tools/perf/util/dso.c b/tools/perf/util/dso.c
index f1a14c0ad26d5..6b08278a4b7bd 100644
--- a/tools/perf/util/dso.c
+++ b/tools/perf/util/dso.c
@@ -346,7 +346,9 @@ int dso__decompress_kmodule_path(struct dso *dso, const char *name,
 {
 	int fd = decompress_kmodule(dso, name, pathname, len);
 
-	close(fd);
+	/* decompress_kmodule() returns -1 on failure, don't close(-1) */
+	if (fd >= 0)
+		close(fd);
 	return fd >= 0 ? 0 : -1;
 }
 
-- 
2.53.0


Thread (1,211 messages) 1,211 messages, 13 authors, last reply 2026-09-21
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