From 0b9b9d659880a3084ec0a5b49f07f387de7b0f0c Mon Sep 17 00:00:00 2001 From: Stephen Hemminger Date: Mon, 8 May 2023 19:21:27 -0700 Subject: tc_exec: don't dereference NULL on calloc failure MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Reported as: tc_exec.c: In function ‘do_exec’: tc_exec.c:103:18: warning: dereference of NULL ‘eu’ [CWE-476] [-Wanalyzer-null-dereference] 103 | return eu->parse_eopt(eu, argc, argv); | ~~^~~~~~~~~~~~ ‘do_exec’: events 1-6 | | 81 | int do_exec(int argc, char **argv) | | ^~~~~~~ | | | | | (1) entry to ‘do_exec’ |...... | 86 | if (argc < 1) { | | ~ | | | | | (2) following ‘false’ branch (when ‘argc > 0’)... |...... | 91 | if (matches(*argv, "help") == 0) { | | ~~~~~~~~~~~~~~~~~~~~~~~ | | || | | |(3) ...to here | | (4) following ‘true’ branch... |...... | 96 | strncpy(kind, *argv, sizeof(kind) - 1); | | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ | | | | | (5) ...to here | 97 | | 98 | eu = get_exec_kind(kind); | | ~~~~~~~~~~~~~~~~~~~ | | | | | (6) calling ‘get_exec_kind’ from ‘do_exec’ | +--> ‘get_exec_kind’: events 7-10 | | 40 | static struct exec_util *get_exec_kind(const char *name) | | ^~~~~~~~~~~~~ | | | | | (7) entry to ‘get_exec_kind’ |...... | 63 | if (eu == NULL) | | ~ | | | | | (8) following ‘true’ branch (when ‘eu’ is NULL)... | 64 | goto noexist; | | ~~~~ | | | | | (9) ...to here |...... | 72 | if (eu) { | | ~ | | | | | (10) following ‘false’ branch (when ‘eu’ is NULL)... | ‘get_exec_kind’: event 11 | |cc1: | (11): ...to here | <------+ | ‘do_exec’: events 12-13 | | 98 | eu = get_exec_kind(kind); | | ^~~~~~~~~~~~~~~~~~~ | | | | | (12) return of NULL to ‘do_exec’ from ‘get_exec_kind’ |...... | 103 | return eu->parse_eopt(eu, argc, argv); | | ~~~~~~~~~~~~~~ | | | | | (13) dereference of NULL ‘eu’ | Fixes: 4bd624467bc6 ("tc: built-in eBPF exec proxy") Signed-off-by: Stephen Hemminger --- tc/tc_exec.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/tc/tc_exec.c b/tc/tc_exec.c index 5d883402..182fbb4c 100644 --- a/tc/tc_exec.c +++ b/tc/tc_exec.c @@ -96,6 +96,10 @@ int do_exec(int argc, char **argv) strncpy(kind, *argv, sizeof(kind) - 1); eu = get_exec_kind(kind); + if (eu == NULL) { + fprintf(stderr, "Allocation failed finding exec\n"); + return -1; + } argc--; argv++; -- cgit v1.2.1