From 18111b130abc0f53b41abbbf82b27d7232ec99f2 Mon Sep 17 00:00:00 2001 From: Richard Levitte Date: Mon, 15 Apr 2019 13:15:55 +0200 Subject: [PATCH] asn1parse: avoid double free |str| was used for multiple conflicting purposes. When using '-strictpem', it's used to uniquely hold a reference to the loaded payload. However, when using '-strparse', |str| was re-used to hold the position from where to start parsing. So when '-strparse' and '-strictpem' are were together, |str| ended up pointing into data pointed at by |at|, and was yet being freed, with the result that the payload it held a reference to became a memory leak, and there was a double free conflict when both |str| and |at| were being freed. The situation is resolved by always having |buf| hold the pointer to the file data, and always and only use |str| to hold the position to start parsing from. Now, we only need to free |buf| properly and not |str|. Fixes #8752 Reviewed-by: Matthias St. Pierre (Merged from https://github.com/openssl/openssl/pull/8753) (cherry picked from commit 4f29f3a29b8b416a501c7166dbbca5284b198f81) --- apps/asn1pars.c | 12 +++++------- 1 file changed, 5 insertions(+), 7 deletions(-) diff --git a/apps/asn1pars.c b/apps/asn1pars.c index 62c70b9cc4..c9a843a363 100644 --- a/apps/asn1pars.c +++ b/apps/asn1pars.c @@ -170,17 +170,17 @@ int asn1parse_main(int argc, char **argv) if (derfile && (derout = bio_open_default(derfile, 'w', FORMAT_ASN1)) == NULL) goto end; + if ((buf = BUF_MEM_new()) == NULL) + goto end; if (strictpem) { - if (PEM_read_bio(in, &name, &header, &str, &num) != - 1) { + if (PEM_read_bio(in, &name, &header, &str, &num) != 1) { BIO_printf(bio_err, "Error reading PEM file\n"); ERR_print_errors(bio_err); goto end; } + buf->data = (char *)str; + buf->length = buf->max = num; } else { - - if ((buf = BUF_MEM_new()) == NULL) - goto end; if (!BUF_MEM_grow(buf, BUFSIZ * 8)) goto end; /* Pre-allocate :-) */ @@ -303,8 +303,6 @@ int asn1parse_main(int argc, char **argv) BUF_MEM_free(buf); OPENSSL_free(name); OPENSSL_free(header); - if (strictpem) - OPENSSL_free(str); ASN1_TYPE_free(at); sk_OPENSSL_STRING_free(osk); return ret; -- 2.25.1