[PATCH 07/17] fs/squashfs: sqfs_search_dir: fix dangling pointer

Richard Genoud
2020-10-14T08:06:12Z

dirs->entry shouldn't be left dangling as it could be freed twice.

Signed-off-by: Richard Genoud <richard.genoud@posteo.net>
---
fs/squashfs/sqfs.c | 5 +++++
1 file changed, 5 insertions(+)

diff --git a/fs/squashfs/sqfs.c b/fs/squashfs/sqfs.c
index c4d74fd4d6d..1df27f7b903 100644
--- a/fs/squashfs/sqfs.c
+++ b/fs/squashfs/sqfs.c
@@ -485,6 +485,7 @@ static int sqfs_search_dir(struct squashfs_dir_stream *dirs, char **token_list,
if (!ret)
break;
free(dirs->entry);
+ dirs->entry = NULL;
}

if (ret) {
@@ -530,6 +531,7 @@ static int sqfs_search_dir(struct squashfs_dir_stream *dirs, char **token_list,
if (ret)
return -EINVAL;
free(dirs->entry);
+ dirs->entry = NULL;

ret = sqfs_search_dir(dirs, sym_tokens, token_count,
m_list, m_count);
@@ -537,6 +539,7 @@ static int sqfs_search_dir(struct squashfs_dir_stream *dirs, char **token_list,
} else if (!sqfs_is_dir(get_unaligned_le16(&dir->inode_type))) {
printf("** Cannot find directory. **\n");
free(dirs->entry);
+ dirs->entry = NULL;
return -EINVAL;
}

@@ -556,6 +559,7 @@ static int sqfs_search_dir(struct squashfs_dir_stream *dirs, char **token_list,
if (sqfs_is_empty_dir(table)) {
printf("Empty directory.\n");
free(dirs->entry);
+ dirs->entry = NULL;
return SQFS_EMPTY_DIR;
}

@@ -564,6 +568,7 @@ static int sqfs_search_dir(struct squashfs_dir_stream *dirs, char **token_list,
dirs->entry_count = dirs->dir_header->count + 1;
dirs->size -= SQFS_DIR_HEADER_SIZE;
free(dirs->entry);
+ dirs->entry = NULL;
}

offset = sqfs_dir_offset(table, m_list, m_count);