From patchwork Thu Jan 30 03:15:19 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jakub Kicinski X-Patchwork-Id: 13954249 X-Patchwork-Delegate: kuba@kernel.org 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 178B02A8C1 for ; Thu, 30 Jan 2025 03:15:23 +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=1738206924; cv=none; b=mJc4O5yNKfZuVhV2y3SQYfiP4CJsTm02OsUSpowdpTSwCKvBRfnJsSZxY7KyITKUx+p1uuJUBDdroKH7ZKf1r7bu+Ob2x3ciA9UJGURyZHQHwnrOlpukijdvCGzWUuPgP6i+2i+8s3Wnd9gQ4S++H3o25E7+2GtP/ho+/ts9YNg= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1738206924; c=relaxed/simple; bh=1N/bb2E9l0WDpQGqtBrNqGqG4OnZj3avmgnn3BZsmpc=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=ROfrcJzlLRxq7Zm+b8NKplj7MQTfsLOnlvlRFi11NU1ZZmzvV85PMJtFxIS6DoOkenJqdSopugskjqGjPADO3/WAEmsOkdzBuL6WkAQohOTeKz3175J3xQJ/dlcteAAZYWNGrGpjiH5iMkMrzNTM9dBcWWiDwjmNfzq2jCvw4bg= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=BxydkxCa; 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="BxydkxCa" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3E9CCC4CEDF; Thu, 30 Jan 2025 03:15:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1738206923; bh=1N/bb2E9l0WDpQGqtBrNqGqG4OnZj3avmgnn3BZsmpc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=BxydkxCagaJYtKZ+WC+6EI9VWKzUEA5jYXpoRQMH2HtlbT58HCshH4u2/vAavAAWB jao2M3qTvZF0s41Xkum/NCDlgStBOtPrB1CEeyJHALh68XOmxXjWfXrQD2+SDvo1+o zGd4yIvBlC/PjRGiKX3xM4ecyIT8hHL3D3ZcEpUrM9lODrFDOpUjzsSCJ3PigUoEAt 1GztOQPJsk+TACtlWyRdtpLtFL0HIEK0gg0hfdNxwG6m3+Z8Lq5IfTZTesmVv0Kn7u dinytjpT/kvJfcLOHMzARuiCikkPWp5EkJ9R5ayKdOuIvxRxSSKipKvXl8i4v0OMDt gdagRQ83Lt+Ow== From: Jakub Kicinski To: davem@davemloft.net Cc: netdev@vger.kernel.org, edumazet@google.com, pabeni@redhat.com, andrew+netdev@lunn.ch, horms@kernel.org, Jakub Kicinski , dsahern@kernel.org, justin.iurman@uliege.be Subject: [PATCH net v2 2/2] net: ipv6: fix dst ref loops in rpl, seg6 and ioam6 lwtunnels Date: Wed, 29 Jan 2025 19:15:19 -0800 Message-ID: <20250130031519.2716843-2-kuba@kernel.org> X-Mailer: git-send-email 2.48.1 In-Reply-To: <20250130031519.2716843-1-kuba@kernel.org> References: <20250130031519.2716843-1-kuba@kernel.org> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Patchwork-Delegate: kuba@kernel.org Some lwtunnels have a dst cache for post-transformation dst. If the packet destination did not change we may end up recording a reference to the lwtunnel in its own cache, and the lwtunnel state will never be freed. Discovered by the ioam6.sh test, kmemleak was recently fixed to catch per-cpu memory leaks. I'm not sure if rpl and seg6 can actually hit this, but in principle I don't see why not. Fixes: 985ec6f5e623 ("net: ipv6: rpl_iptunnel: mitigate 2-realloc issue") Fixes: 40475b63761a ("net: ipv6: seg6_iptunnel: mitigate 2-realloc issue") Fixes: dce525185bc9 ("net: ipv6: ioam6_iptunnel: mitigate 2-realloc issue") Signed-off-by: Jakub Kicinski Reviewed-by: Simon Horman --- v2: - fix spello in the comments v1: https://lore.kernel.org/20250129021346.2333089-2-kuba@kernel.org CC: dsahern@kernel.org CC: justin.iurman@uliege.be --- net/ipv6/ioam6_iptunnel.c | 9 ++++++--- net/ipv6/rpl_iptunnel.c | 9 ++++++--- net/ipv6/seg6_iptunnel.c | 9 ++++++--- 3 files changed, 18 insertions(+), 9 deletions(-) diff --git a/net/ipv6/ioam6_iptunnel.c b/net/ipv6/ioam6_iptunnel.c index 3936c137a572..2c383c12a431 100644 --- a/net/ipv6/ioam6_iptunnel.c +++ b/net/ipv6/ioam6_iptunnel.c @@ -410,9 +410,12 @@ static int ioam6_output(struct net *net, struct sock *sk, struct sk_buff *skb) goto drop; } - local_bh_disable(); - dst_cache_set_ip6(&ilwt->cache, cache_dst, &fl6.saddr); - local_bh_enable(); + /* cache only if we don't create a dst reference loop */ + if (dst->lwtstate != cache_dst->lwtstate) { + local_bh_disable(); + dst_cache_set_ip6(&ilwt->cache, cache_dst, &fl6.saddr); + local_bh_enable(); + } err = skb_cow_head(skb, LL_RESERVED_SPACE(cache_dst->dev)); if (unlikely(err)) diff --git a/net/ipv6/rpl_iptunnel.c b/net/ipv6/rpl_iptunnel.c index 9b7d03563115..0ac4283acdf2 100644 --- a/net/ipv6/rpl_iptunnel.c +++ b/net/ipv6/rpl_iptunnel.c @@ -235,9 +235,12 @@ static int rpl_output(struct net *net, struct sock *sk, struct sk_buff *skb) goto drop; } - local_bh_disable(); - dst_cache_set_ip6(&rlwt->cache, dst, &fl6.saddr); - local_bh_enable(); + /* cache only if we don't create a dst reference loop */ + if (orig_dst->lwtstate != dst->lwtstate) { + local_bh_disable(); + dst_cache_set_ip6(&rlwt->cache, dst, &fl6.saddr); + local_bh_enable(); + } err = skb_cow_head(skb, LL_RESERVED_SPACE(dst->dev)); if (unlikely(err)) diff --git a/net/ipv6/seg6_iptunnel.c b/net/ipv6/seg6_iptunnel.c index eacc4e91b48e..33833b2064c0 100644 --- a/net/ipv6/seg6_iptunnel.c +++ b/net/ipv6/seg6_iptunnel.c @@ -576,9 +576,12 @@ static int seg6_output_core(struct net *net, struct sock *sk, goto drop; } - local_bh_disable(); - dst_cache_set_ip6(&slwt->cache, dst, &fl6.saddr); - local_bh_enable(); + /* cache only if we don't create a dst reference loop */ + if (orig_dst->lwtstate != dst->lwtstate) { + local_bh_disable(); + dst_cache_set_ip6(&slwt->cache, dst, &fl6.saddr); + local_bh_enable(); + } err = skb_cow_head(skb, LL_RESERVED_SPACE(dst->dev)); if (unlikely(err))