FAILED: patch "[PATCH] Squashfs: reject negative file sizes in squashfs_read_inode()" failed to apply to 6.17-stable tree

FAILED: patch "[PATCH] Squashfs: reject negative file sizes in squashfs_read_inode()" failed to apply to 6.17-stable tree

[gregkh]

The patch below does not apply to the 6.17-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.17.y
git checkout FETCH_HEAD
git cherry-pick -x 9f1c14c1de1bdde395f6cc893efa4f80a2ae3b2b
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2025101319-anything-blob-1499@gregkh' --subject-prefix 'PATCH 6.17.y' HEAD^..

Possible dependencies:



thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 9f1c14c1de1bdde395f6cc893efa4f80a2ae3b2b Mon Sep 17 00:00:00 2001
From: Phillip Lougher <phillip@squashfs.org.uk>
Date: Fri, 26 Sep 2025 22:59:35 +0100
Subject: [PATCH] Squashfs: reject negative file sizes in squashfs_read_inode()

Syskaller reports a "WARNING in ovl_copy_up_file" in overlayfs.

This warning is ultimately caused because the underlying Squashfs file
system returns a file with a negative file size.

This commit checks for a negative file size and returns EINVAL.

[phillip@squashfs.org.uk: only need to check 64 bit quantity]
  Link: https://lkml.kernel.org/r/20250926222305.110103-1-phillip@squashfs.org.uk
Link: https://lkml.kernel.org/r/20250926215935.107233-1-phillip@squashfs.org.uk
Fixes: 6545b246a2c8 ("Squashfs: inode operations")
Signed-off-by: Phillip Lougher <phillip@squashfs.org.uk>
Reported-by: syzbot+f754e01116421e9754b9@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/all/68d580e5.a00a0220.303701.0019.GAE@google.com/
Cc: Amir Goldstein <amir73il@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/fs/squashfs/inode.c b/fs/squashfs/inode.c
index ddc65d006063..cceae3b78698 100644
--- a/fs/squashfs/inode.c
+++ b/fs/squashfs/inode.c
@@ -197,6 +197,10 @@ int squashfs_read_inode(struct inode *inode, long long ino)
 			goto failed_read;
 
 		inode->i_size = le64_to_cpu(sqsh_ino->file_size);
+		if (inode->i_size < 0) {
+			err = -EINVAL;
+			goto failed_read;
+		}
 		frag = le32_to_cpu(sqsh_ino->fragment);
 		if (frag != SQUASHFS_INVALID_FRAG) {
 			/*

[PATCH 6.17.y 1/2] Squashfs: add additional inode sanity checking

[Sasha Levin]

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 d5918eba27e37..77eec1772998b 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

[PATCH 6.17.y 2/2] Squashfs: reject negative file sizes in squashfs_read_inode()

[Sasha Levin]

From: Phillip Lougher <phillip@squashfs.org.uk>

[ Upstream commit 9f1c14c1de1bdde395f6cc893efa4f80a2ae3b2b ]

Syskaller reports a "WARNING in ovl_copy_up_file" in overlayfs.

This warning is ultimately caused because the underlying Squashfs file
system returns a file with a negative file size.

This commit checks for a negative file size and returns EINVAL.

[phillip@squashfs.org.uk: only need to check 64 bit quantity]
  Link: https://lkml.kernel.org/r/20250926222305.110103-1-phillip@squashfs.org.uk
Link: https://lkml.kernel.org/r/20250926215935.107233-1-phillip@squashfs.org.uk
Fixes: 6545b246a2c8 ("Squashfs: inode operations")
Signed-off-by: Phillip Lougher <phillip@squashfs.org.uk>
Reported-by: syzbot+f754e01116421e9754b9@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/all/68d580e5.a00a0220.303701.0019.GAE@google.com/
Cc: Amir Goldstein <amir73il@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 fs/squashfs/inode.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/fs/squashfs/inode.c b/fs/squashfs/inode.c
index 77eec1772998b..de8657a77703a 100644
--- a/fs/squashfs/inode.c
+++ b/fs/squashfs/inode.c
@@ -192,6 +192,10 @@ int squashfs_read_inode(struct inode *inode, long long ino)
 			goto failed_read;
 
 		inode->i_size = le64_to_cpu(sqsh_ino->file_size);
+		if (inode->i_size < 0) {
+			err = -EINVAL;
+			goto failed_read;
+		}
 		frag = le32_to_cpu(sqsh_ino->fragment);
 		if (frag != SQUASHFS_INVALID_FRAG) {
 			/*
-- 
2.51.0