5.4-stable review patch. If anyone has any objections, please let me know.
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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 Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/squashfs/inode.c | 4 ++++ 1 file changed, 4 insertions(+)
--- a/fs/squashfs/inode.c +++ b/fs/squashfs/inode.c @@ -193,6 +193,10 @@ int squashfs_read_inode(struct inode *in 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) { /*