From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 C6C783321D8 for ; Sat, 28 Feb 2026 17:53:40 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772301220; cv=none; b=i1do6r+gGplKlCEYrQdkK5sWVtlUVB+p6+wKshxIQaMIbMsLjWjuqjBaKLKJ14Iy6iDe5kE+He13iBoIb9Hlq2j/QMFfzmNTvOQHHGnRubr30TpuwDtceU09srAcox3Qi8lZ1OFaNYM49myAgeEwqewMmDYETA1nNMW/+avV30c= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772301220; c=relaxed/simple; bh=nq9qkBe4okAHoTat6O8vzfoeylYqMxsyWvi3bxn5F+M=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=sAJ3+k4oQOummzFjKgCEagBMmRET3wrA+FjdzdxKn5AL5kSMWeO2Y5Fn895v0mh9wxg+zOkc2BtiIo7Oix0OsgEsPRaVqIpZrez5nZFb/MsNMrgXrzf8oJKGrqAiGSe4ZrvCTJsvWkKpE3lH37Z6ZMywJGtqGV0f5g7bjClMW/s= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=buN6LaVF; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="buN6LaVF" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E13A1C116D0; Sat, 28 Feb 2026 17:53:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1772301220; bh=nq9qkBe4okAHoTat6O8vzfoeylYqMxsyWvi3bxn5F+M=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=buN6LaVFgY49yhtCzr11w3CeKNSgriN2dAr+ETOTrDRZlTt9vaXqyHYtAFHcs7CVx xvNSWuLtcQGKmeqqOlZlCFuI67SatrcANRX4fzTf/tvp/xTMaJMia4MXtEFnYJUOBY css8IK2YAY3GFvdjmwSwxeIcWAQtmz62Yg+XCeCKEPmfi7KzAyBp7sdoMJpe+jMNJ4 ETQi34cMpiLOGbg51qEZW9KG9EfbNsw+TgEiIcU5gmD7L+g8x6ZNiQ4dHq0bEdLYmz Kbm/yBEiIGSKcwOPShtd946ZW0mEL6gMokfX9EVM3pN8fYL8L0l59KZFpZJRaxAK4u Z+LXYFOgpUSLw== From: Sasha Levin To: patches@lists.linux.dev Cc: Jiayuan Chen , syzbot+e136d86d34b42399a8b1@syzkaller.appspotmail.com, Jiayuan Chen , Simon Horman , Steffen Klassert , Sasha Levin Subject: [PATCH 6.18 397/752] xfrm6: fix uninitialized saddr in xfrm6_get_saddr() Date: Sat, 28 Feb 2026 12:41:48 -0500 Message-ID: <20260228174750.1542406-397-sashal@kernel.org> X-Mailer: git-send-email 2.51.0 In-Reply-To: <20260228174750.1542406-1-sashal@kernel.org> References: <20260228174750.1542406-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit From: Jiayuan Chen [ Upstream commit 1799d8abeabc68ec05679292aaf6cba93b343c05 ] xfrm6_get_saddr() does not check the return value of ipv6_dev_get_saddr(). When ipv6_dev_get_saddr() fails to find a suitable source address (returns -EADDRNOTAVAIL), saddr->in6 is left uninitialized, but xfrm6_get_saddr() still returns 0 (success). This causes the caller xfrm_tmpl_resolve_one() to use the uninitialized address in xfrm_state_find(), triggering KMSAN warning: ===================================================== BUG: KMSAN: uninit-value in xfrm_state_find+0x2424/0xa940 xfrm_state_find+0x2424/0xa940 xfrm_resolve_and_create_bundle+0x906/0x5a20 xfrm_lookup_with_ifid+0xcc0/0x3770 xfrm_lookup_route+0x63/0x2b0 ip_route_output_flow+0x1ce/0x270 udp_sendmsg+0x2ce1/0x3400 inet_sendmsg+0x1ef/0x2a0 __sock_sendmsg+0x278/0x3d0 __sys_sendto+0x593/0x720 __x64_sys_sendto+0x130/0x200 x64_sys_call+0x332b/0x3e70 do_syscall_64+0xd3/0xf80 entry_SYSCALL_64_after_hwframe+0x77/0x7f Local variable tmp.i.i created at: xfrm_resolve_and_create_bundle+0x3e3/0x5a20 xfrm_lookup_with_ifid+0xcc0/0x3770 ===================================================== Fix by checking the return value of ipv6_dev_get_saddr() and propagating the error. Fixes: a1e59abf8249 ("[XFRM]: Fix wildcard as tunnel source") Reported-by: syzbot+e136d86d34b42399a8b1@syzkaller.appspotmail.com Closes: https://lore.kernel.org/all/68bf1024.a70a0220.7a912.02c2.GAE@google.com/T/ Signed-off-by: Jiayuan Chen Signed-off-by: Jiayuan Chen Reviewed-by: Simon Horman Signed-off-by: Steffen Klassert Signed-off-by: Sasha Levin --- net/ipv6/xfrm6_policy.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/net/ipv6/xfrm6_policy.c b/net/ipv6/xfrm6_policy.c index 1f19b6f14484c..125ea9a5b8a08 100644 --- a/net/ipv6/xfrm6_policy.c +++ b/net/ipv6/xfrm6_policy.c @@ -57,6 +57,7 @@ static int xfrm6_get_saddr(xfrm_address_t *saddr, struct dst_entry *dst; struct net_device *dev; struct inet6_dev *idev; + int err; dst = xfrm6_dst_lookup(params); if (IS_ERR(dst)) @@ -68,9 +69,11 @@ static int xfrm6_get_saddr(xfrm_address_t *saddr, return -EHOSTUNREACH; } dev = idev->dev; - ipv6_dev_get_saddr(dev_net(dev), dev, ¶ms->daddr->in6, 0, - &saddr->in6); + err = ipv6_dev_get_saddr(dev_net(dev), dev, ¶ms->daddr->in6, 0, + &saddr->in6); dst_release(dst); + if (err) + return -EHOSTUNREACH; return 0; } -- 2.51.0