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 B301F3CE215; Sat, 28 Feb 2026 17:40:09 +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=1772300409; cv=none; b=jQfE2gVy1r0Hwwf+YeBLV2sEJpmIzIFBFfc5R/O2v+R05yTcv6LxaM2+wcsryHF8Ay/BYqxepeEpS7dYNHcr5ENGt5RURlmZNyzs0PMrykYJENoRLHxSblw/UlJ7EJY8ppCpbOeCpbIF9JAf4nOJJ26ZsF7iT2U8OmylHhjnEII= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772300409; c=relaxed/simple; bh=nq9qkBe4okAHoTat6O8vzfoeylYqMxsyWvi3bxn5F+M=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=it+H8RZWXMzuBhi8r7Dn52ODlEwJDwAc2nDFWGpQbMVF8M0Klgh35zFjUuWMkBLBbdBsqC7ZFmqiT00yzrDw6qAzBZt8VryYZ3lOt11hBknzJkP7cWydIcsbc48iQm/TNfF+sRGNMUq8xzyz3nQnADy+uSD1yzKNePLejNDA5LU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=VyJR7ZVt; 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="VyJR7ZVt" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B8D0EC19423; Sat, 28 Feb 2026 17:40:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1772300409; bh=nq9qkBe4okAHoTat6O8vzfoeylYqMxsyWvi3bxn5F+M=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=VyJR7ZVtKWmAvQ1nCGMKrY2M49uHJ3a4za/bz2ctZ4KMf3bmfh1EfQjNShMoqK71A hYjKfLr7N2zGgvl9Fj2+ggYpgTvrcxzNHriuWDs/hBiUhLJhmvclxXLtPkupDDGRVc DsBgSHKTtzlvYGyW8riKZfDSDQRGxLV7LaeBs0Zer54AlSxninx172BCVkXf5dbCa8 N4qctfcYvUIMvXfpoSCboTqUTxnWiHJhQVPa53VZkPqVLczQb+AugcEOE6oMMVw8hV /PFltgl0AKxKiTzIoa4xPNw1B7afyJpylMKiwwrL2XDH8qtKk8fpYvHTOQ5Ar4ncV7 skNloilRIYqZA== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Jiayuan Chen , syzbot+e136d86d34b42399a8b1@syzkaller.appspotmail.com, Jiayuan Chen , Simon Horman , Steffen Klassert , Sasha Levin Subject: [PATCH 6.19 447/844] xfrm6: fix uninitialized saddr in xfrm6_get_saddr() Date: Sat, 28 Feb 2026 12:26:00 -0500 Message-ID: <20260228173244.1509663-448-sashal@kernel.org> X-Mailer: git-send-email 2.51.0 In-Reply-To: <20260228173244.1509663-1-sashal@kernel.org> References: <20260228173244.1509663-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: stable@vger.kernel.org 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