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authorPhillip Lougher <phillip@squashfs.org.uk>2025-10-13 17:45:03 -0400
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2025-10-19 16:21:50 +0200
commit2ec88c3d9f8feb4e5e4b2441f510f9c91dbb233c (patch)
treea21694ae9f17fe691d97b69a8f020d0198a40147
parent49f3a867d948c8bebf0f093f1c6e4fe221a567a5 (diff)
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Squashfs: add additional inode sanity checking
[ 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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--fs/squashfs/inode.c20
1 files changed, 18 insertions, 2 deletions
diff --git a/fs/squashfs/inode.c b/fs/squashfs/inode.c
index c381d08c30c2..b0a5ce62dae4 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;
@@ -184,8 +192,17 @@ 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) {
@@ -200,7 +217,6 @@ 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;