diff options
| author | Phillip Lougher <phillip@squashfs.org.uk> | 2025-09-23 23:06:51 +0100 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2025-09-28 11:36:14 -0700 |
| commit | 9ee94bfbe930a1b39df53fa2d7b31141b780eb5a (patch) | |
| tree | 7a584e2545e77b34122e4db3a1af15a27ba663aa | |
| parent | 1260cbcffa608219fc9188a6cbe9c45a300ef8b5 (diff) | |
Squashfs: add additional inode sanity checking
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>
| -rw-r--r-- | fs/squashfs/inode.c | 20 |
1 files changed, 18 insertions, 2 deletions
diff --git a/fs/squashfs/inode.c b/fs/squashfs/inode.c index bb0529b09adc..8f425dbf9052 100644 --- a/fs/squashfs/inode.c +++ b/fs/squashfs/inode.c @@ -144,8 +144,17 @@ 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) { @@ -159,7 +168,6 @@ 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; @@ -188,8 +196,17 @@ 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) { @@ -204,7 +221,6 @@ 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; |