From: Phillip Lougher phillip@squashfs.org.uk
[ Upstream commit 9ee94bfbe930a1b39df53fa2d7b31141b780eb5a ]
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 Stable-dep-of: 9f1c14c1de1b ("Squashfs: reject negative file sizes in squashfs_read_inode()") Signed-off-by: Sasha Levin sashal@kernel.org --- 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 95a9ff9e23997..eb6f577154d59 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;