lookup: Fix an invalid read

Valgrind reports the following invalid read:

$ sudo valgrind ./nft-parsing-test -f ../jsonfiles/30-rule-lookup.json
==26664== Memcheck, a memory error detector
==26664== Copyright (C) 2002-2013, and GNU GPL'd, by Julian Seward et al.
==26664== Using Valgrind-3.9.0 and LibVEX; rerun with -h for copyright info
==26664== Command: ./nft-parsing-test -f ../jsonfiles/30-rule-lookup.json
==26664==
==26664== Invalid read of size 8
==26664==    at 0x4E45490: nft_rule_expr_lookup_set (lookup.c:50)
==26664==    by 0x4E40B04: nft_rule_expr_set (expr.c:73)
==26664==    by 0x4E44FFF: nft_rule_expr_lookup_json_parse (lookup.c:157)
==26664==    by 0x4E408CD: nft_jansson_expr_parse (jansson.c:206)
==26664==    by 0x4E3B719: nft_jansson_parse_rule (rule.c:606)
==26664==    by 0x4E3F005: nft_ruleset_do_parse (ruleset.c:312)
==26664==    by 0x401479: test_json (nft-parsing-test.c:129)
==26664==    by 0x4017C2: execute_test_file (nft-parsing-test.c:270)
==26664==    by 0x400EBB: main (nft-parsing-test.c:332)
==26664==  Address 0x5c34d40 is 0 bytes inside a block of size 5 alloc'd
==26664==    at 0x4C274A0: malloc (vg_replace_malloc.c:291)
==26664==    by 0x56834FF: ??? (in /usr/lib/x86_64-linux-gnu/libjansson.so.4.6.0)
==26664==    by 0x5685825: json_string_nocheck (in /usr/lib/x86_64-linux-gnu/libjansson.so.4.6.0)
==26664==    by 0x5682A3F: ??? (in /usr/lib/x86_64-linux-gnu/libjansson.so.4.6.0)
==26664==    by 0x5682ADE: ??? (in /usr/lib/x86_64-linux-gnu/libjansson.so.4.6.0)
==26664==    by 0x5682C5D: ??? (in /usr/lib/x86_64-linux-gnu/libjansson.so.4.6.0)
==26664==    by 0x5682ADE: ??? (in /usr/lib/x86_64-linux-gnu/libjansson.so.4.6.0)
==26664==    by 0x5682ADE: ??? (in /usr/lib/x86_64-linux-gnu/libjansson.so.4.6.0)
==26664==    by 0x5682C5D: ??? (in /usr/lib/x86_64-linux-gnu/libjansson.so.4.6.0)
==26664==    by 0x5682ADE: ??? (in /usr/lib/x86_64-linux-gnu/libjansson.so.4.6.0)
==26664==    by 0x5682EDD: ??? (in /usr/lib/x86_64-linux-gnu/libjansson.so.4.6.0)
==26664==    by 0x5683295: json_loadf (in /usr/lib/x86_64-linux-gnu/libjansson.so.4.6.0)
==26664==
==26664== Invalid read of size 8
==26664==    at 0x4E45497: nft_rule_expr_lookup_set (lookup.c:50)
==26664==    by 0x4E40B04: nft_rule_expr_set (expr.c:73)
==26664==    by 0x4E44FFF: nft_rule_expr_lookup_json_parse (lookup.c:157)
==26664==    by 0x4E408CD: nft_jansson_expr_parse (jansson.c:206)
==26664==    by 0x4E3B719: nft_jansson_parse_rule (rule.c:606)
==26664==    by 0x4E3F005: nft_ruleset_do_parse (ruleset.c:312)
==26664==    by 0x401479: test_json (nft-parsing-test.c:129)
==26664==    by 0x4017C2: execute_test_file (nft-parsing-test.c:270)
==26664==    by 0x400EBB: main (nft-parsing-test.c:332)
==26664==  Address 0x5c34d48 is 3 bytes after a block of size 5 alloc'd
==26664==    at 0x4C274A0: malloc (vg_replace_malloc.c:291)
==26664==    by 0x56834FF: ??? (in /usr/lib/x86_64-linux-gnu/libjansson.so.4.6.0)
==26664==    by 0x5685825: json_string_nocheck (in /usr/lib/x86_64-linux-gnu/libjansson.so.4.6.0)
==26664==    by 0x5682A3F: ??? (in /usr/lib/x86_64-linux-gnu/libjansson.so.4.6.0)
==26664==    by 0x5682ADE: ??? (in /usr/lib/x86_64-linux-gnu/libjansson.so.4.6.0)
==26664==    by 0x5682C5D: ??? (in /usr/lib/x86_64-linux-gnu/libjansson.so.4.6.0)
==26664==    by 0x5682ADE: ??? (in /usr/lib/x86_64-linux-gnu/libjansson.so.4.6.0)
==26664==    by 0x5682ADE: ??? (in /usr/lib/x86_64-linux-gnu/libjansson.so.4.6.0)
==26664==    by 0x5682C5D: ??? (in /usr/lib/x86_64-linux-gnu/libjansson.so.4.6.0)
==26664==    by 0x5682ADE: ??? (in /usr/lib/x86_64-linux-gnu/libjansson.so.4.6.0)
==26664==    by 0x5682EDD: ??? (in /usr/lib/x86_64-linux-gnu/libjansson.so.4.6.0)
==26664==    by 0x5683295: json_loadf (in /usr/lib/x86_64-linux-gnu/libjansson.so.4.6.0)

Signed-off-by: Ana Rey <anarey@gmail.com>

diff --git a/src/expr/lookup.c b/src/expr/lookup.c
index 5e0bf75985edd3cbc5825a514142e2f3f610d854..50282a8c143f2a18f4202b9eaa83666941130eef 100644 (file)
--- a/src/expr/lookup.c
+++ b/src/expr/lookup.c
@@ -47,8 +47,8 @@ nft_rule_expr_lookup_set(struct nft_rule_expr *e, uint16_t type,
                lookup->dreg = *((uint32_t *)data);
                break;
        case NFT_EXPR_LOOKUP_SET:
-               memcpy(lookup->set_name, data, IFNAMSIZ);
-               lookup->set_name[IFNAMSIZ-1] = '\0';
+               snprintf(lookup->set_name, sizeof(lookup->set_name), "%s",
+                        (const char *)data);
                break;
        default:
                return -1;