[PATCH 2/8] mtd-utils: Fix potential negative arguments passed to close(2)

[David Oberhollenzer <david.oberhollenzer@xxxxxxxxxxxxx>]

Many tools open a file descriptor, close it a the end and have some
form of error path in between that jumps to the end.

In some cases, if opening the file fails the error path is taken and
the utility ends up closing one or more invalid file descriptors. It's
technically not a real issue but something that pretty much any static
analysis tool barks at.

Signed-off-by: David Oberhollenzer <david.oberhollenzer@xxxxxxxxxxxxx>
---
 nand-utils/nanddump.c                  | 3 ++-
 nand-utils/nandwrite.c                 | 3 ++-
 nor-utils/rfddump.c                    | 2 +-
 tests/fs-tests/stress/atoms/fwrite00.c | 4 +++-
 4 files changed, 8 insertions(+), 4 deletions(-)

diff --git a/nand-utils/nanddump.c b/nand-utils/nanddump.c
index 841ed67..62699e0 100644
--- a/nand-utils/nanddump.c
+++ b/nand-utils/nanddump.c
@@ -549,7 +549,8 @@ int main(int argc, char * const argv[])
 
 closeall:
 	close(fd);
-	close(ofd);
+	if (ofd > 0 && ofd != STDOUT_FILENO)
+		close(ofd);
 	free(oobbuf);
 	free(readbuf);
 	exit(EXIT_FAILURE);
diff --git a/nand-utils/nandwrite.c b/nand-utils/nandwrite.c
index 8f21593..e8a210c 100644
--- a/nand-utils/nandwrite.c
+++ b/nand-utils/nandwrite.c
@@ -605,7 +605,8 @@ int main(int argc, char * const argv[])
 	failed = false;
 
 closeall:
-	close(ifd);
+	if (ifd > 0 && ifd != STDIN_FILENO)
+		close(ifd);
 	libmtd_close(mtd_desc);
 	free(filebuf);
 	close(fd);
diff --git a/nor-utils/rfddump.c b/nor-utils/rfddump.c
index 4ad2f91..01ab4c2 100644
--- a/nor-utils/rfddump.c
+++ b/nor-utils/rfddump.c
@@ -324,7 +324,7 @@ int main(int argc, char *argv[])
 	return 0;
 
 err:
-	if (out_fd)
+	if (out_fd > 0)
 		close(out_fd);
 
 	close(fd);
diff --git a/tests/fs-tests/stress/atoms/fwrite00.c b/tests/fs-tests/stress/atoms/fwrite00.c
index 3406bba..877c63c 100644
--- a/tests/fs-tests/stress/atoms/fwrite00.c
+++ b/tests/fs-tests/stress/atoms/fwrite00.c
@@ -138,7 +138,9 @@ static void filestress00(void)
 			deleted = 1;
 		}
 	}
-	CHECK(close(fd) != -1);
+	if (fd > 0) {
+		CHECK(close(fd) != -1);
+	}
 	/* Sleep */
 	if (tests_sleep_parameter > 0) {
 		unsigned us = tests_sleep_parameter * 1000;
-- 
2.24.1


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