If sb_min_blocksize returns 0, squashfs_fill_super exits without freeing
allocated memory (sb->s_fs_info).
Fix this by moving the call to sb_min_blocksize to before memory is
allocated.
Fixes: 734aa85390ea ("Squashfs: check return result of sb_min_blocksize")
Reported-by: Scott GUO <scottzhguo@tencent.com>
Closes: https://lore.kernel.org/all/20250811061921.3807353-1-scott_gzh@163.com
Signed-off-by: Phillip Lougher <phillip@squashfs.org.uk>
---
fs/squashfs/super.c | 14 +++++++-------
1 file changed, 7 insertions(+), 7 deletions(-)
diff --git a/fs/squashfs/super.c b/fs/squashfs/super.c
index 992ea0e37257..4465cf05603a 100644
--- a/fs/squashfs/super.c
+++ b/fs/squashfs/super.c
@@ -187,10 +187,15 @@ static int squashfs_fill_super(struct super_block *sb, struct fs_context *fc)
unsigned short flags;
unsigned int fragments;
u64 lookup_table_start, xattr_id_table_start, next_table;
- int err;
+ int err, devblksize = sb_min_blocksize(sb, SQUASHFS_DEVBLK_SIZE);
TRACE("Entered squashfs_fill_superblock\n");
+ if (!devblksize) {
+ errorf(fc, "squashfs: unable to set blocksize\n");
+ return -EINVAL;
+ }
+
sb->s_fs_info = kzalloc(sizeof(*msblk), GFP_KERNEL);
if (sb->s_fs_info == NULL) {
ERROR("Failed to allocate squashfs_sb_info\n");
@@ -201,12 +206,7 @@ static int squashfs_fill_super(struct super_block *sb, struct fs_context *fc)
msblk->panic_on_errors = (opts->errors == Opt_errors_panic);
- msblk->devblksize = sb_min_blocksize(sb, SQUASHFS_DEVBLK_SIZE);
- if (!msblk->devblksize) {
- errorf(fc, "squashfs: unable to set blocksize\n");
- return -EINVAL;
- }
-
+ msblk->devblksize = devblksize;
msblk->devblksize_log2 = ffz(~msblk->devblksize);
mutex_init(&msblk->meta_index_mutex);
--
2.39.2