From 040ad83b0e8aa065fd2fc641cacba8491a8b186d Mon Sep 17 00:00:00 2001 From: Eric Biggers Date: Sun, 19 Apr 2026 23:33:47 -0700 Subject: [PATCH] crypto: drbg - Fix ineffective sanity check Fix drbg_healthcheck_sanity() to correctly check the return value of drbg_generate(). drbg_generate() returns 0 on success, or a negative errno value on failure. drbg_healthcheck_sanity() incorrectly assumed that it returned a positive value on success. This didn't make the sanity check fail, but it made it ineffective. Fixes: cde001e4c3c3 ("crypto: rng - RNGs must return 0 in success case") Cc: stable@vger.kernel.org Signed-off-by: Eric Biggers Signed-off-by: Herbert Xu --- crypto/drbg.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) diff --git a/crypto/drbg.c b/crypto/drbg.c index de4c69032155e..f23b431bd4902 100644 --- a/crypto/drbg.c +++ b/crypto/drbg.c @@ -1737,7 +1737,6 @@ static int drbg_kcapi_seed(struct crypto_rng *tfm, */ static inline int __init drbg_healthcheck_sanity(void) { - int len = 0; #define OUTBUFLEN 16 unsigned char buf[OUTBUFLEN]; struct drbg_state *drbg = NULL; @@ -1782,11 +1781,11 @@ static inline int __init drbg_healthcheck_sanity(void) max_request_bytes = drbg_max_request_bytes(drbg); drbg_string_fill(&addtl, buf, max_addtllen + 1); /* overflow addtllen with additional info string */ - len = drbg_generate(drbg, buf, OUTBUFLEN, &addtl); - BUG_ON(0 < len); + ret = drbg_generate(drbg, buf, OUTBUFLEN, &addtl); + BUG_ON(ret == 0); /* overflow max_bits */ - len = drbg_generate(drbg, buf, (max_request_bytes + 1), NULL); - BUG_ON(0 < len); + ret = drbg_generate(drbg, buf, max_request_bytes + 1, NULL); + BUG_ON(ret == 0); /* overflow max addtllen with personalization string */ ret = drbg_seed(drbg, &addtl, false); -- 2.47.3