[U-Boot] [PATCH v2 2/2] fs/fat: Check malloc return values and fix memory leaks

1 Oct 2017

Check malloc() return values and properly unwind on errors so
memory allocated for fat_itr structures get freed properly.
Also fixes a leak of fsdata.fatbuf in fat_size().
Fixes: 2460098cffacd1 ("fs/fat: Reduce stack usage")
Reported-by: Coverity (CID: 167225, 167233, 167234)
Signed-off-by: Tuomas Tynkkynen tuomas.tynkkynen@iki.fi
---
v2: New patch
---
 fs/fat/fat.c | 30 ++++++++++++++++++++----------
 1 file changed, 20 insertions(+), 10 deletions(-)

diff --git a/fs/fat/fat.c b/fs/fat/fat.c
index 35941c1498..7fe78439cf 100644
--- a/fs/fat/fat.c
+++ b/fs/fat/fat.c
@@ -1039,12 +1039,15 @@ int fat_exists(const char *filename)
    int ret;
itr = malloc_cache_aligned(sizeof(fat_itr));
+	if (!itr)
+		return 0;
    ret = fat_itr_root(itr, &fsdata);
    if (ret)
-		return 0;
+		goto out;
ret = fat_itr_resolve(itr, filename, TYPE_ANY);
    free(fsdata.fatbuf);
+out:
    free(itr);
    return ret == 0;
 }
@@ -1056,9 +1059,11 @@ int fat_size(const char *filename, loff_t *size)
    int ret;
itr = malloc_cache_aligned(sizeof(fat_itr));
+	if (!itr)
+		return -ENOMEM;
    ret = fat_itr_root(itr, &fsdata);
    if (ret)
-		return ret;
+		goto out_free_itr;
ret = fat_itr_resolve(itr, filename, TYPE_FILE);
    if (ret) {
@@ -1072,12 +1077,13 @@ int fat_size(const char *filename, loff_t *size)
    		*size = 0;
    		ret = 0;
    	}
-		goto out;
+		goto out_free_both;
    }
*size = FAT2CPU32(itr->dent->size);
+out_free_both:
    free(fsdata.fatbuf);
-out:
+out_free_itr:
    free(itr);
    return ret;
 }
@@ -1090,19 +1096,22 @@ int file_fat_read_at(const char *filename, loff_t pos, void *buffer,
    int ret;
itr = malloc_cache_aligned(sizeof(fat_itr));
+	if (!itr)
+		return -ENOMEM;
    ret = fat_itr_root(itr, &fsdata);
    if (ret)
-		return ret;
+		goto out_free_itr;
ret = fat_itr_resolve(itr, filename, TYPE_FILE);
    if (ret)
-		goto out;
+		goto out_free_both;
printf("reading %s\n", filename);
    ret = get_contents(&fsdata, itr->dent, pos, buffer, maxsize, actread);
-out:
+out_free_both:
    free(fsdata.fatbuf);
+out_free_itr:
    free(itr);
    return ret;
 }
@@ -1148,17 +1157,18 @@ int fat_opendir(const char *filename, struct fs_dir_stream **dirsp)
ret = fat_itr_root(&dir->itr, &dir->fsdata);
    if (ret)
-		goto fail;
+		goto fail_free_dir;
ret = fat_itr_resolve(&dir->itr, filename, TYPE_DIR);
    if (ret)
-		goto fail;
+		goto fail_free_both;
*dirsp = (struct fs_dir_stream *)dir;
    return 0;
-fail:
+fail_free_both:
    free(dir->fsdata.fatbuf);
+fail_free_dir:
    free(dir);
    return ret;
 }
-- 
2.13.0


    