drivers/rtc/rtc-efi.c: check for invalid data coming back from UEFI

In particular seeing zero in eft->month is problematic, as it results in
-1 (converted to unsigned int, i.e.  yielding 0xffffffff) getting passed
to rtc_year_days(), where the value gets used as an array index
(normally resulting in a crash).  This was observed with the driver
enabled on x86 on some Fujitsu system (with possibly not up to date
firmware, but anyway).

Perhaps efi_read_alarm() should not fail if neither enabled nor pending
are set, but the returned time is invalid?

Signed-off-by: Jan Beulich <[email protected]>
Reported-by: Raymund Will <[email protected]>
Cc: Alessandro Zummo <[email protected]>
Cc: Jingoo Han <[email protected]>
Acked-by: Lee, Chun-Yi <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

0 files changed, 0 insertions, 0 deletions