tree 6218d591858a633cbe524527609c1423954911c5
parent 8f358d63bffe3d457a5fb1c485eb5e964d2b6fed
author Christoph Probst <kernel@probst.it> 1557242200 +0200
committer Greg Kroah-Hartman <gregkh@linuxfoundation.org> 1558801607 +0200

cifs: fix strcat buffer overflow and reduce raciness in smb21_set_oplock_level()

commit 6a54b2e002c9d00b398d35724c79f9fe0d9b38fb upstream.

Change strcat to strncpy in the "None" case to fix a buffer overflow
when cinode->oplock is reset to 0 by another thread accessing the same
cinode. It is never valid to append "None" to any other message.

Consolidate multiple writes to cinode->oplock to reduce raciness.

Signed-off-by: Christoph Probst <kernel@probst.it>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
CC: Stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>