scsi: scsi_transport_fc: Adjust struct fc_nl_event flex array usage

In order to help the compiler reason about the destination buffer in struct
fc_nl_event, add a flexible array member for this purpose.  However, since
the header is UAPI, it must not change size or layout, so a union is used.

The allocation size calculations are also corrected (it was potentially
allocating an extra 8 bytes), and the padding is zeroed to avoid leaking
kernel heap memory contents.

Detected at run-time by the recently added memcpy() bounds checking:

  memcpy: detected field-spanning write (size 8) of single field "&event->event_data" at drivers/scsi/scsi_transport_fc.c:581 (size 4)

Link: https://lore.kernel.org/linux-next/[email protected]/
Link: https://lore.kernel.org/r/[email protected]
Cc: "James E.J. Bottomley" <[email protected]>
Cc: "Martin K. Petersen" <[email protected]>
Cc: [email protected]
Reported-by: Sachin Sant <[email protected]>
Tested-by: Sachin Sant <[email protected]>
Reviewed-by: James Smart <[email protected]>
Signed-off-by: Kees Cook <[email protected]>
Signed-off-by: Martin K. Petersen <[email protected]>

0 files changed, 0 insertions, 0 deletions