From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id EAD81257854; Thu, 28 May 2026 20:18:00 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779999481; cv=none; b=JMTqQA2Vgiyhyc2HHLMwgNstlhP0E4mGKNqeVaS8zZxADCvVNwJmpUDno30gNcnKANiPrQzrVZ1VG2EPvZ3EPVHFybSsNlmc1MOUZuskFGMrQe1HyFkHIO1jkisxyvx3FgrPnIgtfgRK4xELjgyP/qBITIVb+GMlveF5MRWnv7A= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779999481; c=relaxed/simple; bh=JerZbnRYFg5UmT/o9MXZw0DUwZAHpi8l3XTrpk3AQls=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=URPWMNySDQjZJwcqOZzuj/371La+KEVX1SK6tOZCfffqMu9RcV2n5rzsFJ3mWVjSt0TFy3K/HVIZyn6iQJCQMBHm7ZJ5O0klIchOu0cQmXAzpXcOakBKERQ8Cmh5PYMjmtFWTZTNpbbZ1MRKExGr2VTn2H6hIQGoH6dCv+nXpwU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=nq67Or+A; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="nq67Or+A" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0ED041F000E9; Thu, 28 May 2026 20:17:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1779999480; bh=D4X3FaFMq8R0bHFzYTZ5tY9fglUwy8Fc9FXhtIi5Jbo=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=nq67Or+A+Y8gsO+OpfaMt7GhII8n4/KQqbzQzR3vTP9bYHKGMRJ22mKaucfYFIjwZ O18SEhcGHznwRnbXc1R7PoOuMGI6qfarP3PCLDv/D/U12eIaiIUnMD60uCRBry1Fj9 /sAfRPYSBTyvnVDNJ4StxKIQfgQJIKRtMi/Px8yQ= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Justin Iurman , Ido Schimmel , Jakub Kicinski Subject: [PATCH 6.18 083/377] ipv6: ioam: add NULL check for idev in ipv6_hop_ioam() Date: Thu, 28 May 2026 21:45:21 +0200 Message-ID: <20260528194640.779926911@linuxfoundation.org> X-Mailer: git-send-email 2.54.0 In-Reply-To: <20260528194638.371537336@linuxfoundation.org> References: <20260528194638.371537336@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Justin Iurman commit d4ea0dfd75011b78cebf3808f98ac4c4f51a6fb9 upstream. Reported by Sashiko: The function ipv6_hop_ioam() accesses __in6_dev_get(skb->dev)->cnf.ioam6_enabled without validating the returned idev pointer. Because addrconf_ifdown() can concurrently clear dev->ip6_ptr via RCU, __in6_dev_get() can return NULL during interface teardown, which could cause a NULL pointer dereference when processing an IOAM Hop-by-Hop option. Let's add a check and use SKB_DROP_REASON_IPV6DISABLED accordingly. Fixes: 9ee11f0fff20 ("ipv6: ioam: Data plane support for Pre-allocated Trace") Cc: stable@vger.kernel.org Signed-off-by: Justin Iurman Reviewed-by: Ido Schimmel Link: https://patch.msgid.link/20260517183059.29140-1-justin.iurman@gmail.com Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman --- net/ipv6/exthdrs.c | 15 +++++++++++++-- 1 file changed, 13 insertions(+), 2 deletions(-) --- a/net/ipv6/exthdrs.c +++ b/net/ipv6/exthdrs.c @@ -910,16 +910,27 @@ static bool ipv6_hop_ra(struct sk_buff * static bool ipv6_hop_ioam(struct sk_buff *skb, int optoff) { + enum skb_drop_reason drop_reason; struct ioam6_trace_hdr *trace; struct ioam6_namespace *ns; + struct inet6_dev *idev; struct ioam6_hdr *hdr; + drop_reason = SKB_DROP_REASON_IP_INHDR; + /* Bad alignment (must be 4n-aligned) */ if (optoff & 3) goto drop; + /* Does the device still have IPv6 configuration? */ + idev = __in6_dev_get(skb->dev); + if (!idev) { + drop_reason = SKB_DROP_REASON_IPV6DISABLED; + goto drop; + } + /* Ignore if IOAM is not enabled on ingress */ - if (!READ_ONCE(__in6_dev_get(skb->dev)->cnf.ioam6_enabled)) + if (!READ_ONCE(idev->cnf.ioam6_enabled)) goto ignore; /* Truncated Option header */ @@ -972,7 +983,7 @@ ignore: return true; drop: - kfree_skb_reason(skb, SKB_DROP_REASON_IP_INHDR); + kfree_skb_reason(skb, drop_reason); return false; }