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 935DE330D23 for ; Fri, 29 May 2026 23:53:19 +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=1780098800; cv=none; b=SeAFHXjk40v68g4zEnyZrboha2CkmvUEZtrUXjjyo50aoVn6nDZf8tir473+zOsEYWuGEWsTGewu84LiFoTgjo5Hza7bIAsa9H+X+QPFF2aTeA7enoIYWi9Ea5Ryss49qja4C0zl405XxTGHwN4Pimg51qeqbCluR3zB48EjMRw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780098800; c=relaxed/simple; bh=RLdKLF03ChFz+xtF5ixUP09+GLDXkuEcuHuQg/iJSyg=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=EzWZSPjURNlEvxUfAQspskCaFDE83wFx6M3WdtMrtHhfU7pXw4/t5HYP2G0YZ4+4GmcXAmwRubh1EQh43ff4J8skldxbkYybQvpPjGBT23KijNhH6XTogCkJKQasNk6jlpBZxIx3ZMMDmqB9y1op/vCwYuXNR69XxBffpph6n5o= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=EEWBBs/z; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="EEWBBs/z" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E78A41F00898; Fri, 29 May 2026 23:53:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1780098799; bh=jsOxGa7xQ0cTYImQ7FZul0c71zTOBckOXV41izLI9cQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=EEWBBs/zCRFWhf5f3s9WX2IQbm+Qf3+ljEv+Z1FNy0kl4Y+1T76cTbz7VlzazH5KR CXdv7pgesxbMMROtc3f50rBMydcNQrT0cVys1h1ly8JD2R15bTegx1WAR4UkX5ddsP w6k2xzXrrA/C6DpHo4ywzSifLAppgx7XzsfKkw7+wtRm4JyPdgCeGPa1q4RDa1GLyA l2tfQEl1I45+OYoJGaJS+7q3VIQNFLH6RMraO2l1L/xK4tZeUQ8xO+N4AbEpiAYKvR 8Cv8JnETlhOuVroanUqG1kCVt0h+QFZVBpxf6fSLtyWyKR1+Px8rKtI0oDxDqFmyz5 3vZlEW6qQnRow== From: Sasha Levin To: stable@vger.kernel.org Cc: Justin Iurman , Ido Schimmel , Jakub Kicinski , Sasha Levin Subject: [PATCH 6.6.y 2/2] ipv6: ioam: add NULL check for idev in ipv6_hop_ioam() Date: Fri, 29 May 2026 19:53:16 -0400 Message-ID: <20260529235316.1963855-2-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260529235316.1963855-1-sashal@kernel.org> References: <2026052812-uncoated-spry-43e1@gregkh> <20260529235316.1963855-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Justin Iurman [ Upstream commit d4ea0dfd75011b78cebf3808f98ac4c4f51a6fb9 ] 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: Sasha Levin --- net/ipv6/exthdrs.c | 15 +++++++++++++-- 1 file changed, 13 insertions(+), 2 deletions(-) diff --git a/net/ipv6/exthdrs.c b/net/ipv6/exthdrs.c index 404555311bc74..f6f6830cc466e 100644 --- a/net/ipv6/exthdrs.c +++ b/net/ipv6/exthdrs.c @@ -919,16 +919,27 @@ static bool ipv6_hop_ra(struct sk_buff *skb, int optoff) 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 */ @@ -978,7 +989,7 @@ static bool ipv6_hop_ioam(struct sk_buff *skb, int optoff) return true; drop: - kfree_skb_reason(skb, SKB_DROP_REASON_IP_INHDR); + kfree_skb_reason(skb, drop_reason); return false; } -- 2.53.0