squashfs: fix memory leak in squashfs_fill_super

commit b64700d41b upstream.

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.

Link: https://lkml.kernel.org/r/20250811223740.110392-1-phillip@squashfs.org.uk
Fixes: 734aa85390 ("Squashfs: check return result of sb_min_blocksize")
Signed-off-by: Phillip Lougher <phillip@squashfs.org.uk>
Reported-by: Scott GUO <scottzhguo@tencent.com>
Closes: https://lore.kernel.org/all/20250811061921.3807353-1-scott_gzh@163.com
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Phillip Lougher 2025-08-11 23:37:40 +01:00 committed by Greg Kroah-Hartman
parent 7a556ae35d
commit b14850b047

View File

@ -122,10 +122,15 @@ 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");
@ -135,12 +140,7 @@ 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);