pstore: ram_core: fix possible overflow in persistent_ram_init_ecc()

In persistent_ram_init_ecc(), on 64-bit arches DIV_ROUND_UP() will return
64-bit value since persistent_ram_zone::buffer_size has type size_t which
is derived from the 64-bit *unsigned long*, while the ecc_blocks variable
this value gets assigned to has (always 32-bit) *int* type.  Even if that
value fits into *int* type, an overflow is still possible when calculating
the size_t typed ecc_total variable further below since there's no cast to
any 64-bit type before multiplication.  Declaring the ecc_blocks variable
as *size_t* should fix this mess...

Found by Linux Verification Center (linuxtesting.org) with the SVACE static
analysis tool.

Fixes: 9cc05ad97c57 ("staging: android: persistent_ram: refactor ecc support")
Signed-off-by: Sergey Shtylyov <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Kees Cook <[email protected]>

0 files changed, 0 insertions, 0 deletions