5.4-stable review patch. If anyone has any objections, please let me know.
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From: Phillip Lougher phillip@squashfs.org.uk
commit b64700d41bdc4e9f82f1346c15a3678ebb91a89c 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: 734aa85390ea ("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 --- fs/squashfs/super.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-)
--- a/fs/squashfs/super.c +++ b/fs/squashfs/super.c @@ -74,10 +74,15 @@ static int squashfs_fill_super(struct su 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"); @@ -85,12 +90,7 @@ static int squashfs_fill_super(struct su } msblk = sb->s_fs_info;
- 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);