From: Phillip Lougher Date: Fri, 26 Sep 2025 21:59:35 +0000 (+0100) Subject: Squashfs: reject negative file sizes in squashfs_read_inode() X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=9f1c14c1de1bdde395f6cc893efa4f80a2ae3b2b;p=thirdparty%2Fkernel%2Fstable.git 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 Reported-by: syzbot+f754e01116421e9754b9@syzkaller.appspotmail.com Closes: https://lore.kernel.org/all/68d580e5.a00a0220.303701.0019.GAE@google.com/ Cc: Amir Goldstein Cc: Signed-off-by: Andrew Morton --- diff --git a/fs/squashfs/inode.c b/fs/squashfs/inode.c index ddc65d0060633..cceae3b78698c 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) { /*