3.4-stable review patch. If anyone has any objections, please let me know.
------------------ From: Neil Horman <[email protected]> commit 714b33d15130cbb5ab426456d4e3de842d6c5b8a upstream. Stephan Mueller reported to me recently a error in random number generation in the ansi cprng. If several small requests are made that are less than the instances block size, the remainder for loop code doesn't increment rand_data_valid in the last iteration, meaning that the last bytes in the rand_data buffer gets reused on the subsequent smaller-than-a-block request for random data. The fix is pretty easy, just re-code the for loop to make sure that rand_data_valid gets incremented appropriately Signed-off-by: Neil Horman <[email protected]> Reported-by: Stephan Mueller <[email protected]> CC: Stephan Mueller <[email protected]> CC: Petr Matousek <[email protected]> CC: Herbert Xu <[email protected]> CC: "David S. Miller" <[email protected]> Signed-off-by: Herbert Xu <[email protected]> Cc: Luis Henriques <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- crypto/ansi_cprng.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/crypto/ansi_cprng.c +++ b/crypto/ansi_cprng.c @@ -230,11 +230,11 @@ remainder: */ if (byte_count < DEFAULT_BLK_SZ) { empty_rbuf: - for (; ctx->rand_data_valid < DEFAULT_BLK_SZ; - ctx->rand_data_valid++) { + while (ctx->rand_data_valid < DEFAULT_BLK_SZ) { *ptr = ctx->rand_data[ctx->rand_data_valid]; ptr++; byte_count--; + ctx->rand_data_valid++; if (byte_count == 0) goto done; } -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
