Commit 580039e8 authored Dec 03, 2014 by Johan Hedberg Committed by Marcel Holtmann Dec 03, 2014

Bluetooth: Fix false-positive "uninitialized" compiler warning



Some gcc versions don't seem to be able to properly track the flow of
the smp_cmd_pairing_random() function and end up causing the following
types of (false-positive) warnings:

 smp.c:1995:6: warning: ‘nb’ may be used uninitialized in this function [-Wmaybe-uninitialized]
   err = smp_g2(smp->tfm_cmac, pkax, pkbx, na, nb, &passkey);
 smp.c:1995:6: warning: ‘na’ may be used uninitialized in this function [-Wmaybe-uninitialized]
   err = smp_g2(smp->tfm_cmac, pkax, pkbx, na, nb, &passkey);
       ^
 smp.c:1995:6: warning: ‘pkbx’ may be used uninitialized in this function [-Wmaybe-uninitialized]
   err = smp_g2(smp->tfm_cmac, pkax, pkbx, na, nb, &passkey);
       ^
 smp.c:1995:6: warning: ‘pkax’ may be used uninitialized in this function [-Wmaybe-uninitialized]
   err = smp_g2(smp->tfm_cmac, pkax, pkbx, na, nb, &passkey);

This patch fixes the issue by moving the pkax/pkbx and na/nb
initialization earlier in the function.

Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

parent 7f376cd6

net/bluetooth/smp.c

+12 −10

Original line number	Diff line number	Diff line
		@@ -1947,6 +1947,18 @@ static u8 smp_cmd_pairing_random(struct l2cap_conn conn, struct sk_buff skb)
		if (!test_bit(SMP_FLAG_SC, &smp->flags))
		return smp_random(smp);

		if (hcon->out) {
		pkax = smp->local_pk;
		pkbx = smp->remote_pk;
		na = smp->prnd;
		nb = smp->rrnd;
		} else {
		pkax = smp->remote_pk;
		pkbx = smp->local_pk;
		na = smp->rrnd;
		nb = smp->prnd;
		}

		if (smp->method == REQ_OOB) {
		if (!hcon->out)
		smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM,
		@@ -1969,20 +1981,10 @@ static u8 smp_cmd_pairing_random(struct l2cap_conn conn, struct sk_buff skb)

		if (memcmp(smp->pcnf, cfm, 16))
		return SMP_CONFIRM_FAILED;

		pkax = smp->local_pk;
		pkbx = smp->remote_pk;
		na = smp->prnd;
		nb = smp->rrnd;
		} else {
		smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, sizeof(smp->prnd),
		smp->prnd);
		SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK);

		pkax = smp->remote_pk;
		pkbx = smp->local_pk;
		na = smp->rrnd;
		nb = smp->prnd;
		}

		mackey_and_ltk:

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