Squashfs: reject negative file sizes in squashfs_read_inode()

[ Upstream commit 9f1c14c1de ]

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: 6545b246a2 ("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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Phillip Lougher 2025-10-13 13:36:49 -04:00 committed by Greg Kroah-Hartman
parent c2188189bb
commit f271155ff3

View File

@ -193,6 +193,10 @@ 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) {
/*