From: Sasha Levin <sashal@kernel.org>
To: stable@vger.kernel.org
Cc: Phillip Lougher <phillip@squashfs.org.uk>,
Andrew Morton <akpm@linux-foundation.org>,
Sasha Levin <sashal@kernel.org>
Subject: [PATCH 5.10.y 1/2] Squashfs: add additional inode sanity checking
Date: Mon, 13 Oct 2025 17:57:00 -0400 [thread overview]
Message-ID: <20251013215701.3645486-1-sashal@kernel.org> (raw)
In-Reply-To: <2025101321-ripening-subscript-11b6@gregkh>
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;
--
2.51.0
next prev parent reply other threads:[~2025-10-13 21:57 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-10-13 7:49 FAILED: patch "[PATCH] Squashfs: reject negative file sizes in squashfs_read_inode()" failed to apply to 5.10-stable tree gregkh
2025-10-13 21:57 ` Sasha Levin [this message]
2025-10-13 21:57 ` [PATCH 5.10.y 2/2] Squashfs: reject negative file sizes in squashfs_read_inode() Sasha Levin
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