efi/cper: Read only validated fields in cper_mem_err_pack()

cper_mem_err_pack() copies extended, rank, mem_array_handle and
mem_dev_handle unconditionally. Those live at offsets 73 to 79, past the
end of struct cper_sec_mem_err_old, the 73-byte UEFI 2.1/2.2 layout that
older firmware still emits and that cper_estatus_print_section() admits.
On such a record the copy reads up to seven bytes past the payload, and off
the end of the error status block when that section is the last one.

Copy each of the four only when its validation bit is set, and zero it
otherwise. Nothing is lost: a 2.1/2.2 record leaves those bits clear, and
every consumer of struct cper_mem_err_compact already gates the fields on
the same bits. Zeroing also stops callers reading them back out of the
uninitialised on-stack struct they pass in.

Reported-by: sashiko-bot@kernel.org
Closes: https://sashiko.dev/#/patchset/20260714231835.303081-1-dave.jiang@intel.com?part=7
Fixes: 2dfb7d51a61d ("trace, RAS: Add eMCA trace event interface")
Reviewed-by: Hanjun Guo <guohanjun@huawei.com>
Reviewed-by: Shuai Xue <xueshuai@linux.alibaba.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Link: https://patch.msgid.link/20260904172337.1409775-11-dave.jiang@intel.com
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

0 files changed, 0 insertions, 0 deletions