Set pointer to list of expression to NULL and check that it is set on before using it. In function ‘expr_evaluate_concat’, inlined from ‘expr_evaluate’ at evaluate.c:2488:10: evaluate.c:1338:20: warning: ‘expressions’ may be used uninitialized [-Wmaybe-uninitialized] 1338 | if (runaway) { | ^ evaluate.c: In function ‘expr_evaluate’: evaluate.c:1321:33: note: ‘expressions’ was declared here 1321 | const struct list_head *expressions; | ^~~~~~~~~~~ Reported-by: Florian Westphal <fw@xxxxxxxxx> Fixes: 508f3a270531 ("netlink: swap byteorder of value component in concatenation of intervals") Signed-off-by: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx> --- src/evaluate.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/src/evaluate.c b/src/evaluate.c index 3a524aab0e12..d0279e335a4e 100644 --- a/src/evaluate.c +++ b/src/evaluate.c @@ -1318,7 +1318,7 @@ static int expr_evaluate_concat(struct eval_ctx *ctx, struct expr **expr) uint32_t type = dtype ? dtype->type : 0, ntype = 0; int off = dtype ? dtype->subtypes : 0; unsigned int flags = EXPR_F_CONSTANT | EXPR_F_SINGLETON; - const struct list_head *expressions; + const struct list_head *expressions = NULL; struct expr *i, *next, *key = NULL; const struct expr *key_ctx = NULL; bool runaway = false; @@ -1395,7 +1395,7 @@ static int expr_evaluate_concat(struct eval_ctx *ctx, struct expr **expr) dsize_bytes = div_round_up(dsize, BITS_PER_BYTE); (*expr)->field_len[(*expr)->field_count++] = dsize_bytes; size += netlink_padded_len(dsize); - if (key) { + if (key && expressions) { if (list_is_last(&key->list, expressions)) runaway = true; -- 2.30.2