From: Phillip Lougher <phillip@squashfs.org.uk> mainline inclusion from mainline-v6.17-rc4 commit 9ee94bfbe930a1b39df53fa2d7b31141b780eb5a category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/ID6BW5 CVE: CVE-2025-40200 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... -------------------------------- Patch series "Squashfs: performance improvement and a sanity check". This patchset adds an additional sanity check when reading regular file inodes, and adds support for SEEK_DATA/SEEK_HOLE lseek() whence values. This patch (of 2): Add an additional sanity check when reading regular file inodes. A regular file if the file size is an exact multiple of the filesystem block size cannot have a fragment. This is because by definition a fragment block stores tailends which are not a whole block in size. Link: https://lkml.kernel.org/r/20250923220652.568416-1-phillip@squashfs.org.uk Link: https://lkml.kernel.org/r/20250923220652.568416-2-phillip@squashfs.org.uk Signed-off-by: Phillip Lougher <phillip@squashfs.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Long Li <leo.lilong@huawei.com> --- fs/squashfs/inode.c | 20 ++++++++++++++++++-- 1 file changed, 18 insertions(+), 2 deletions(-) diff --git a/fs/squashfs/inode.c b/fs/squashfs/inode.c index d5918eba27e3..77eec1772998 100644 --- a/fs/squashfs/inode.c +++ b/fs/squashfs/inode.c @@ -140,8 +140,17 @@ int squashfs_read_inode(struct inode *inode, long long ino) if (err < 0) goto failed_read; + inode->i_size = le32_to_cpu(sqsh_ino->file_size); frag = le32_to_cpu(sqsh_ino->fragment); if (frag != SQUASHFS_INVALID_FRAG) { + /* + * the file cannot have a fragment (tailend) and have a + * file size a multiple of the block size + */ + if ((inode->i_size & (msblk->block_size - 1)) == 0) { + err = -EINVAL; + goto failed_read; + } frag_offset = le32_to_cpu(sqsh_ino->offset); frag_size = squashfs_frag_lookup(sb, frag, &frag_blk); if (frag_size < 0) { @@ -155,7 +164,6 @@ int squashfs_read_inode(struct inode *inode, long long ino) } set_nlink(inode, 1); - inode->i_size = le32_to_cpu(sqsh_ino->file_size); inode->i_fop = &generic_ro_fops; inode->i_mode |= S_IFREG; inode->i_blocks = ((inode->i_size - 1) >> 9) + 1; @@ -183,8 +191,17 @@ int squashfs_read_inode(struct inode *inode, long long ino) if (err < 0) goto failed_read; + inode->i_size = le64_to_cpu(sqsh_ino->file_size); frag = le32_to_cpu(sqsh_ino->fragment); if (frag != SQUASHFS_INVALID_FRAG) { + /* + * the file cannot have a fragment (tailend) and have a + * file size a multiple of the block size + */ + if ((inode->i_size & (msblk->block_size - 1)) == 0) { + err = -EINVAL; + goto failed_read; + } frag_offset = le32_to_cpu(sqsh_ino->offset); frag_size = squashfs_frag_lookup(sb, frag, &frag_blk); if (frag_size < 0) { @@ -199,7 +216,6 @@ int squashfs_read_inode(struct inode *inode, long long ino) xattr_id = le32_to_cpu(sqsh_ino->xattr); set_nlink(inode, le32_to_cpu(sqsh_ino->nlink)); - inode->i_size = le64_to_cpu(sqsh_ino->file_size); inode->i_op = &squashfs_inode_ops; inode->i_fop = &generic_ro_fops; inode->i_mode |= S_IFREG; -- 2.39.2