Commit c708c57e authored Apr 20, 2011 by Jan Glauber Committed by Martin Schwidefsky Apr 20, 2011

[S390] prng: prevent access beyond end of stack



While initializing the state of the prng only the first 8 bytes of
random data where used, the second 8 bytes were read from the memory
after the stack. If only 64 bytes of the kernel stack are used and
CONFIG_DEBUG_PAGEALLOC is enabled a kernel panic may occur because of
the invalid page access. Use the correct multiplicator to stay within
the random data buffer.

Signed-off-by: Jan Glauber <jang@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

parent 65f8da47

arch/s390/crypto/prng.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -76,7 +76,7 @@ static void prng_seed(int nbytes)

		/* Add the entropy */
		while (nbytes >= 8) {
		((__u64 )parm_block) ^= ((__u64 )buf+i*8);
		((__u64 )parm_block) ^= ((__u64 )buf+i);
		prng_add_entropy();
		i += 8;
		nbytes -= 8;