[PATCH] objtool: Fix memory leak in objtool_create_backup

From: cz18811105578
Date: Tue Mar 01 2022 - 11:37:02 EST


From: Zong Cao <cz18811105578@xxxxxxxxx>

The error handling branch did not properly free the memory before
return, which would cause memory leak.

Fixes: 8ad15c690084 ("objtool: Add --backup")
Signed-off-by: Zong Cao <cz18811105578@xxxxxxxxx>
---
tools/objtool/objtool.c | 21 ++++++++++++++++-----
1 file changed, 16 insertions(+), 5 deletions(-)

diff --git a/tools/objtool/objtool.c b/tools/objtool/objtool.c
index bdf699f6552b..1f4734c84382 100644
--- a/tools/objtool/objtool.c
+++ b/tools/objtool/objtool.c
@@ -62,19 +62,19 @@ static bool objtool_create_backup(const char *_objname)
d = open(name, O_CREAT|O_WRONLY|O_TRUNC, 0644);
if (d < 0) {
perror("failed to create backup file");
- return false;
+ goto free_name;
}

s = open(_objname, O_RDONLY);
if (s < 0) {
perror("failed to open orig file");
- return false;
+ goto close_d;
}

buf = malloc(4096);
if (!buf) {
perror("failed backup data malloc");
- return false;
+ goto close_s;
}

while ((l = read(s, buf, 4096)) > 0) {
@@ -83,7 +83,7 @@ static bool objtool_create_backup(const char *_objname)
t = write(d, base, l);
if (t < 0) {
perror("failed backup write");
- return false;
+ goto free_buf;
}
base += t;
l -= t;
@@ -92,7 +92,7 @@ static bool objtool_create_backup(const char *_objname)

if (l < 0) {
perror("failed backup read");
- return false;
+ goto free_buf;
}

free(name);
@@ -101,6 +101,17 @@ static bool objtool_create_backup(const char *_objname)
close(s);

return true;
+
+free_buf:
+ free(buf);
+close_s:
+ close(s);
+close_d:
+ close(d);
+free_name:
+ free(name);
+ return false;
+
}

struct objtool_file *objtool_open_read(const char *_objname)
--
2.30.1 (Apple Git-130)