The patch below does not apply to the 6.12-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-6.12.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 '2025101320-sliceable-electable-e1b9@gregkh' --subject-prefix 'PATCH 6.12.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) { /*
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;
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) { /*
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