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 C96B52494F0; Wed, 8 Apr 2026 18:22:17 +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=1775672537; cv=none; b=alnnLcZfkFdIxVaOqfwEbXUaaaC30KREuRw1opKLzfbF8gv0ehYeKj2UXmWQ2rkahXKHlc5oYkYDOGSYDoXEX5vFc2HHm22CDszOzXxcR8Vkn9wgPuGT2XcpelEJj30/PYGk+WsYla4IvOCX3jsYYjkqMe/BAAPzSq+lz9YsNeo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775672537; c=relaxed/simple; bh=jADT5Xmwf0NZCVx5Iv0jOxudpRXhN5O7bb4aAI7ymB8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=PiwGsnxGxyi3dJQDdMBIcR8FX8hygsHeXzlBErp0IE0TcZAJtMr5RDJeWGKuoBKd1gexcehIchmwVWUS6sWXwE4R79q4NvWs/tFBIdDKZAaz6C/WKo9Tyb6PC1iFXEkBYtMbGtBg1r4OXURm2UkD41TtlKe3Dhq2F2wxgn1Ek4I= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=gPz18asp; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="gPz18asp" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5F3ADC19421; Wed, 8 Apr 2026 18:22:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1775672537; bh=jADT5Xmwf0NZCVx5Iv0jOxudpRXhN5O7bb4aAI7ymB8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=gPz18asp2YiLJvB9pHh/YcnWjRXuSzV+CfqAyh9nScVtVyrfwQODefdeDygleqFqw UrDSHZBHaMkdBRX6FXkxOc2IhRkpNH5oF+zkXZPB0cuxKWoB3OOJTlKdzU0XTClRev keqUloZdh/OJSD7FTuugKDeQQyW7g8hzjmA1+f74= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Jakub Kicinski , Paolo Abeni , Sasha Levin Subject: [PATCH 6.6 028/160] ipv6: prevent possible UaF in addrconf_permanent_addr() Date: Wed, 8 Apr 2026 20:01:55 +0200 Message-ID: <20260408175914.262321597@linuxfoundation.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260408175913.177092714@linuxfoundation.org> References: <20260408175913.177092714@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 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Paolo Abeni [ Upstream commit fd63f185979b047fb22a0dfc6bd94d0cab6a6a70 ] The mentioned helper try to warn the user about an exceptional condition, but the message is delivered too late, accessing the ipv6 after its possible deletion. Reorder the statement to avoid the possible UaF; while at it, place the warning outside the idev->lock as it needs no protection. Reported-by: Jakub Kicinski Closes: https://sashiko.dev/#/patchset/8c8bfe2e1a324e501f0e15fef404a77443fd8caf.1774365668.git.pabeni%40redhat.com Fixes: f1705ec197e7 ("net: ipv6: Make address flushing on ifdown optional") Signed-off-by: Paolo Abeni Link: https://patch.msgid.link/ef973c3a8cb4f8f1787ed469f3e5391b9fe95aa0.1774601542.git.pabeni@redhat.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- net/ipv6/addrconf.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c index 7fcc68dcf144b..32fa6236dacdd 100644 --- a/net/ipv6/addrconf.c +++ b/net/ipv6/addrconf.c @@ -3611,12 +3611,12 @@ static void addrconf_permanent_addr(struct net *net, struct net_device *dev) if ((ifp->flags & IFA_F_PERMANENT) && fixup_permanent_addr(net, idev, ifp) < 0) { write_unlock_bh(&idev->lock); - in6_ifa_hold(ifp); - ipv6_del_addr(ifp); - write_lock_bh(&idev->lock); net_info_ratelimited("%s: Failed to add prefix route for address %pI6c; dropping\n", idev->dev->name, &ifp->addr); + in6_ifa_hold(ifp); + ipv6_del_addr(ifp); + write_lock_bh(&idev->lock); } } -- 2.53.0