Security update for the Linux Kernel

The SUSE Linux Enterprise 12 SP3 kernel was updated to receive various security and bugfixes. The following security bugs were fixed: - CVE-2021-26930: Fixed an improper error handling in blkback's grant mapping (XSA-365 bsc#1181843). - CVE-2021-26931: Fixed an issue where Linux kernel was treating grant mapping errors as bugs (XSA-362 bsc#1181753). - CVE-2021-26932: Fixed improper error handling issues in Linux grant mapping (XSA-361 bsc#1181747). - CVE-2020-28374: Fixed insufficient identifier checking in the LIO SCSI target code which could have been used by remote attackers to read or write files via directory traversal in an XCOPY request (bsc#178372). The following non-security bugs were fixed: - cifs: report error instead of invalid when revalidating a dentry fails (bsc#1177440). - xen/netback: fix spurious event detection for common event case (bsc#1182175).