bpf: fix a number of valgrind issues

This patch fixes a number of uninitialized memory problems caught by
valgrind.  These aren't the typical uninitialized memory issues, but
rather an issue with our block hashing and the structure padding areas
not being init/reset.  This isn't something that I expect would have
caused a lot of problems, but they would have been a major
head-scratcher and difficult to reproduce.

Signed-off-by: Paul Moore <pmoore@redhat.com>

1 files changed, 12 insertions, 7 deletions

diff --git a/src/gen_bpf.c b/src/gen_bpf.c
index f491217..e11e892 100644
--- a/src/gen_bpf.c
+++ b/src/gen_bpf.c
@@ -892,6 +892,7 @@ static struct bpf_blk *_gen_bpf_chain(struct bpf_state *state,
 	struct bpf_instr *i_iter;
 	const struct db_arg_chain_tree *c_iter;
 	unsigned int iter;
+	struct bpf_jump nxt_jump_tmp;
 
 	if (chain == NULL) {
 		b_head = _gen_bpf_action(state, NULL, sys->action);
@@ -929,16 +930,18 @@ static struct bpf_blk *_gen_bpf_chain(struct bpf_state *state,
 				if (i_iter->jt.type == TGT_NXT) {
 					if (i_iter->jt.tgt.nxt != 0)
 						goto chain_failure;
-					i_iter->jt = (b_next == NULL ?
-						      *nxt_jump :
-						      _BPF_JMP_BLK(b_next));
+					if (b_next == NULL)
+						i_iter->jt = *nxt_jump;
+					else
+						i_iter->jt=_BPF_JMP_BLK(b_next);
 				}
 				if (i_iter->jf.type == TGT_NXT) {
 					if (i_iter->jf.tgt.nxt != 0)
 						goto chain_failure;
-					i_iter->jf = (b_next == NULL ?
-						      *nxt_jump :
-						      _BPF_JMP_BLK(b_next));
+					if (b_next == NULL)
+						i_iter->jf = *nxt_jump;
+					else
+						i_iter->jf=_BPF_JMP_BLK(b_next);
 				}
 			}
 			b_iter = b_next;
@@ -946,16 +949,18 @@ static struct bpf_blk *_gen_bpf_chain(struct bpf_state *state,
 	}
 
 	/* resolve all of the blocks */
+	memset(&nxt_jump_tmp, 0, sizeof(nxt_jump_tmp));
 	b_iter = b_tail;
 	do {
 		/* b_iter may change after resolving, so save the linkage */
 		b_prev = b_iter->lvl_prv;
 		b_next = b_iter->lvl_nxt;
 
+		nxt_jump_tmp = _BPF_JMP_BLK(b_next);
 		b_iter = _gen_bpf_chain_lvl_res(state, sys, b_iter,
 						(b_next == NULL ?
 						 nxt_jump :
-						 &_BPF_JMP_BLK(b_next)));
+						 &nxt_jump_tmp));
 		if (b_iter == NULL)
 			goto chain_failure;