[PATCH] debugfs: fix filehandle leak in copy_file()

[PATCH] debugfs: fix filehandle leak in copy_file()

[Andreas Dilger]

Fix a file handle leak for the target file in copy_file() when error
handlers return without closing the file.  Instead, clean up at the
end of the function to handle cleanup in normal and error cases.

Minor other code style cleanups.

Signed-off-by: Andreas Dilger <adilger@dilger.ca>
---
 debugfs/debugfs.c | 27 ++++++++++++++-------------
 1 file changed, 14 insertions(+), 13 deletions(-)

diff --git a/debugfs/debugfs.c b/debugfs/debugfs.c
index 326f41e..e53e0b9 100644
--- a/debugfs/debugfs.c
+++ b/debugfs/debugfs.c
@@ -1578,10 +1578,11 @@ void do_find_free_inode(int argc, char *argv[])
 }
 
 #ifndef READ_ONLY
-static errcode_t copy_file(int fd, ext2_ino_t newfile, int bufsize, int make_holes)
+static errcode_t copy_file(int fd, ext2_ino_t newfile, int bufsize,
+			   int make_holes)
 {
 	ext2_file_t	e2_file;
-	errcode_t	retval;
+	errcode_t	retval, close_ret;
 	int		got;
 	unsigned int	written;
 	char		*buf;
@@ -1597,15 +1598,14 @@ static errcode_t copy_file(int fd, ext2_ino_t newfile, int bufsize, int make_hol
 	retval = ext2fs_get_mem(bufsize, &buf);
 	if (retval) {
 		com_err("copy_file", retval, "can't allocate buffer\n");
-		return retval;
+		goto out_close;
 	}
 
 	/* This is used for checking whether the whole block is zero */
 	retval = ext2fs_get_memzero(bufsize, &zero_buf);
 	if (retval) {
-		com_err("copy_file", retval, "can't allocate buffer\n");
-		ext2fs_free_mem(&buf);
-		return retval;
+		com_err("copy_file", retval, "can't allocate zero buffer\n");
+		goto out_free_buf;
 	}
 
 	while (1) {
@@ -1624,7 +1624,8 @@ static errcode_t copy_file(int fd, ext2_ino_t newfile, int bufsize, int make_hol
 			cmp = memcmp(ptr, zero_buf, got);
 			if (cmp == 0) {
 				 /* The whole block is zero, make a hole */
-				retval = ext2fs_file_lseek(e2_file, got, EXT2_SEEK_CUR, NULL);
+				retval = ext2fs_file_lseek(e2_file, got,
+							   EXT2_SEEK_CUR, NULL);
 				if (retval)
 					goto fail;
 				got = 0;
@@ -1642,15 +1643,15 @@ static errcode_t copy_file(int fd, ext2_ino_t newfile, int bufsize, int make_hol
 			ptr += written;
 		}
 	}
-	ext2fs_free_mem(&buf);
-	ext2fs_free_mem(&zero_buf);
-	retval = ext2fs_file_close(e2_file);
-	return retval;
 
 fail:
-	ext2fs_free_mem(&buf);
 	ext2fs_free_mem(&zero_buf);
-	(void) ext2fs_file_close(e2_file);
+out_free_buf:
+	ext2fs_free_mem(&buf);
+out_close:
+	close_ret = ext2fs_file_close(e2_file);
+	if (retval == 0)
+		retval = close_ret;
 	return retval;
 }
 
-- 
1.9.3

Re: [PATCH] debugfs: fix filehandle leak in copy_file()

[Theodore Ts'o]

On Tue, May 20, 2014 at 04:30:35PM -0600, Andreas Dilger wrote:
> Fix a file handle leak for the target file in copy_file() when error
> handlers return without closing the file.  Instead, clean up at the
> end of the function to handle cleanup in normal and error cases.
> 
> Minor other code style cleanups.
> 
> Signed-off-by: Andreas Dilger <adilger@dilger.ca>

Thanks, applied.

					- Ted