fs: fix potential memory leak on i/o errors in .read()

Make sure to free the line buffer pointer when aborting a
`getline()` / `getdelim()` based read operation on i/o errors.

As an example, this issue could be triggered by receiving a broken
pipe error while attempting to read a line from stdin.

Signed-off-by: Jo-Philipp Wich <jo@mein.io>

1 files changed, 6 insertions, 2 deletions

diff --git a/lib/fs.c b/lib/fs.c
index 220bd74..e3f8a4a 100644
--- a/lib/fs.c
+++ b/lib/fs.c
@@ -130,8 +130,10 @@ uc_fs_read_common(uc_vm_t *vm, size_t nargs, const char *type)
 		if (llen == 4 && !strcmp(lstr, "line")) {
 			llen = getline(&p, &rlen, *fp);
 
-			if (llen == -1)
+			if (llen == -1) {
+				free(p);
 				err_return(errno);
+			}
 
 			len = (size_t)llen;
 		}
@@ -158,8 +160,10 @@ uc_fs_read_common(uc_vm_t *vm, size_t nargs, const char *type)
 		else if (llen == 1) {
 			llen = getdelim(&p, &rlen, *lstr, *fp);
 
-			if (llen == -1)
+			if (llen == -1) {
+				free(p);
 				err_return(errno);
+			}
 
 			len = (size_t)llen;
 		}