From: Sasha Levin <sashal@kernel.org>
To: stable@vger.kernel.org, rcn@igalia.com
Cc: Sasha Levin <sashal@kernel.org>
Subject: Re: [PATCH 6.6 v3 1/3] net: Reference bpf_redirect_info via task_struct on PREEMPT_RT.
Date: Thu, 27 Feb 2025 00:08:19 -0500 [thread overview]
Message-ID: <20250226153136-b2eabb2b52d4bcec@stable.kernel.org> (raw)
In-Reply-To: <20250226-20250204-kasan-slab-use-after-free-read-in-dev_map_enqueue__submit-v3-1-360efec441ba@igalia.com>
[ Sasha's backport helper bot ]
Hi,
Summary of potential issues:
⚠️ Found follow-up fixes in mainline
The upstream commit SHA1 provided is correct: 401cb7dae8130fd34eb84648e02ab4c506df7d5e
WARNING: Author mismatch between patch and upstream commit:
Backport author: =?utf-8?q?Ricardo_Ca=C3=B1uelo_Navarro?=<rcn@igalia.com>
Commit author: Sebastian Andrzej Siewior<bigeasy@linutronix.de>
Found fixes commits:
55e802468e1d sfc: Don't invoke xdp_do_flush() from netpoll.
157f29152b61 netkit: Assign missing bpf_net_context
fecef4cd42c6 tun: Assign missing bpf_net_context.
Note: The patch differs from the upstream commit:
---
1: 401cb7dae8130 ! 1: fe2023f9238ce net: Reference bpf_redirect_info via task_struct on PREEMPT_RT.
@@ Metadata
## Commit message ##
net: Reference bpf_redirect_info via task_struct on PREEMPT_RT.
+ [ Upstream commit 401cb7dae8130fd34eb84648e02ab4c506df7d5e ]
+
The XDP redirect process is two staged:
- bpf_prog_run_xdp() is invoked to run a eBPF program which inspects the
packet and makes decisions. While doing that, the per-CPU variable
@@ Commit message
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Link: https://patch.msgid.link/20240620132727.660738-15-bigeasy@linutronix.de
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
+ [rcn: the backport addresses the differences in
+ net/core/dev.c:napi_threaded_poll(), busy_poll_stop(), napi_busy_loop()
+ and net_rx_action() between upstream and stable. This allows the patch
+ to be applied without bringing additional dependencies, such as
+ dad6b9770263 ("net: Allow to use SMP threads for backlog NAPI."). These
+ changes allow applying the patch on stable without bringing the whole
+ related series.
+ The rest of the changes are made to adapt context lines and are
+ unrelated to the purpose of the patch.]
+ Signed-off-by: Ricardo Cañuelo Navarro <rcn@igalia.com>
## include/linux/filter.h ##
@@ include/linux/filter.h: struct bpf_nh_params {
@@ net/bpf/test_run.c: static int bpf_test_run(struct bpf_prog *prog, void *ctx, u3
## net/core/dev.c ##
@@ net/core/dev.c: sch_handle_ingress(struct sk_buff *skb, struct packet_type **pt_prev, int *ret,
+ struct net_device *orig_dev, bool *another)
{
struct bpf_mprog_entry *entry = rcu_dereference_bh(skb->dev->tcx_ingress);
- enum skb_drop_reason drop_reason = SKB_DROP_REASON_TC_INGRESS;
+ struct bpf_net_context __bpf_net_ctx, *bpf_net_ctx;
int sch_ret;
@@ net/core/dev.c: sch_handle_ingress(struct sk_buff *skb, struct packet_type **pt_
+ bpf_net_ctx_clear(bpf_net_ctx);
return NULL;
case TC_ACT_SHOT:
- kfree_skb_reason(skb, drop_reason);
+ kfree_skb_reason(skb, SKB_DROP_REASON_TC_INGRESS);
*ret = NET_RX_DROP;
+ bpf_net_ctx_clear(bpf_net_ctx);
return NULL;
@@ net/core/dev.c: sch_handle_ingress(struct sk_buff *skb, struct packet_type **pt_
return skb;
}
-@@ net/core/dev.c: sch_handle_egress(struct sk_buff *skb, int *ret, struct net_device *dev)
+@@ net/core/dev.c: static __always_inline struct sk_buff *
+ sch_handle_egress(struct sk_buff *skb, int *ret, struct net_device *dev)
{
struct bpf_mprog_entry *entry = rcu_dereference_bh(dev->tcx_egress);
- enum skb_drop_reason drop_reason = SKB_DROP_REASON_TC_EGRESS;
+ struct bpf_net_context __bpf_net_ctx, *bpf_net_ctx;
int sch_ret;
@@ net/core/dev.c: sch_handle_egress(struct sk_buff *skb, int *ret, struct net_devi
+ bpf_net_ctx_clear(bpf_net_ctx);
return NULL;
case TC_ACT_SHOT:
- kfree_skb_reason(skb, drop_reason);
+ kfree_skb_reason(skb, SKB_DROP_REASON_TC_EGRESS);
*ret = NET_XMIT_DROP;
+ bpf_net_ctx_clear(bpf_net_ctx);
return NULL;
@@ net/core/dev.c: sch_handle_egress(struct sk_buff *skb, int *ret, struct net_devi
return skb;
}
-@@ net/core/dev.c: enum {
- static void busy_poll_stop(struct napi_struct *napi, void *have_poll_lock,
- unsigned flags, u16 budget)
+@@ net/core/dev.c: static void __busy_poll_stop(struct napi_struct *napi, bool skip_schedule)
+ static void busy_poll_stop(struct napi_struct *napi, void *have_poll_lock, bool prefer_busy_poll,
+ u16 budget)
{
+ struct bpf_net_context __bpf_net_ctx, *bpf_net_ctx;
bool skip_schedule = false;
unsigned long timeout;
int rc;
-@@ net/core/dev.c: static void busy_poll_stop(struct napi_struct *napi, void *have_poll_lock,
+@@ net/core/dev.c: static void busy_poll_stop(struct napi_struct *napi, void *have_poll_lock, bool
clear_bit(NAPI_STATE_IN_BUSY_POLL, &napi->state);
local_bh_disable();
+ bpf_net_ctx = bpf_net_ctx_set(&__bpf_net_ctx);
- if (flags & NAPI_F_PREFER_BUSY_POLL) {
+ if (prefer_busy_poll) {
napi->defer_hard_irqs_count = READ_ONCE(napi->dev->napi_defer_hard_irqs);
-@@ net/core/dev.c: static void busy_poll_stop(struct napi_struct *napi, void *have_poll_lock,
+@@ net/core/dev.c: static void busy_poll_stop(struct napi_struct *napi, void *have_poll_lock, bool
netpoll_poll_unlock(have_poll_lock);
if (rc == budget)
__busy_poll_stop(napi, skip_schedule);
@@ net/core/dev.c: static void busy_poll_stop(struct napi_struct *napi, void *have_
local_bh_enable();
}
-@@ net/core/dev.c: static void __napi_busy_loop(unsigned int napi_id,
+@@ net/core/dev.c: void napi_busy_loop(unsigned int napi_id,
{
unsigned long start_time = loop_end ? busy_loop_current_time() : 0;
int (*napi_poll)(struct napi_struct *napi, int budget);
@@ net/core/dev.c: static void __napi_busy_loop(unsigned int napi_id,
void *have_poll_lock = NULL;
struct napi_struct *napi;
-@@ net/core/dev.c: static void __napi_busy_loop(unsigned int napi_id,
+@@ net/core/dev.c: void napi_busy_loop(unsigned int napi_id,
int work = 0;
local_bh_disable();
@@ net/core/dev.c: static void __napi_busy_loop(unsigned int napi_id,
if (!napi_poll) {
unsigned long val = READ_ONCE(napi->state);
-@@ net/core/dev.c: static void __napi_busy_loop(unsigned int napi_id,
+@@ net/core/dev.c: void napi_busy_loop(unsigned int napi_id,
+ if (work > 0)
__NET_ADD_STATS(dev_net(napi->dev),
LINUX_MIB_BUSYPOLLRXPACKETS, work);
- skb_defer_free_flush(this_cpu_ptr(&softnet_data));
+ bpf_net_ctx_clear(bpf_net_ctx);
local_bh_enable();
if (!loop_end || loop_end(loop_end_arg, start_time))
-@@ net/core/dev.c: static int napi_thread_wait(struct napi_struct *napi)
+@@ net/core/dev.c: static void skb_defer_free_flush(struct softnet_data *sd)
- static void napi_threaded_poll_loop(struct napi_struct *napi)
+ static int napi_threaded_poll(void *data)
{
+ struct bpf_net_context __bpf_net_ctx, *bpf_net_ctx;
+ struct napi_struct *napi = data;
struct softnet_data *sd;
- unsigned long last_qs = jiffies;
-
-@@ net/core/dev.c: static void napi_threaded_poll_loop(struct napi_struct *napi)
- void *have;
-
- local_bh_disable();
-+ bpf_net_ctx = bpf_net_ctx_set(&__bpf_net_ctx);
-+
- sd = this_cpu_ptr(&softnet_data);
- sd->in_napi_threaded_poll = true;
-
-@@ net/core/dev.c: static void napi_threaded_poll_loop(struct napi_struct *napi)
- net_rps_action_and_irq_enable(sd);
- }
- skb_defer_free_flush(sd);
-+ bpf_net_ctx_clear(bpf_net_ctx);
- local_bh_enable();
-
- if (!repoll)
+ void *have;
+@@ net/core/dev.c: static int napi_threaded_poll(void *data)
+ bool repoll = false;
+
+ local_bh_disable();
++ bpf_net_ctx = bpf_net_ctx_set(&__bpf_net_ctx);
+ sd = this_cpu_ptr(&softnet_data);
+ sd->in_napi_threaded_poll = true;
+
+@@ net/core/dev.c: static int napi_threaded_poll(void *data)
+ net_rps_action_and_irq_enable(sd);
+ }
+ skb_defer_free_flush(sd);
++ bpf_net_ctx_clear(bpf_net_ctx);
+ local_bh_enable();
+
+ if (!repoll)
@@ net/core/dev.c: static __latent_entropy void net_rx_action(struct softirq_action *h)
struct softnet_data *sd = this_cpu_ptr(&softnet_data);
unsigned long time_limit = jiffies +
- usecs_to_jiffies(READ_ONCE(net_hotdata.netdev_budget_usecs));
+ usecs_to_jiffies(READ_ONCE(netdev_budget_usecs));
+ struct bpf_net_context __bpf_net_ctx, *bpf_net_ctx;
- int budget = READ_ONCE(net_hotdata.netdev_budget);
+ int budget = READ_ONCE(netdev_budget);
LIST_HEAD(list);
LIST_HEAD(repoll);
@@ net/core/filter.c: static const struct bpf_func_proto bpf_clone_redirect_proto =
-DEFINE_PER_CPU(struct bpf_redirect_info, bpf_redirect_info);
-EXPORT_PER_CPU_SYMBOL_GPL(bpf_redirect_info);
-
- static struct net_device *skb_get_peer_dev(struct net_device *dev)
- {
- const struct net_device_ops *ops = dev->netdev_ops;
-@@ net/core/filter.c: static struct net_device *skb_get_peer_dev(struct net_device *dev)
-
int skb_do_redirect(struct sk_buff *skb)
{
- struct bpf_redirect_info *ri = this_cpu_ptr(&bpf_redirect_info);
@@ net/core/filter.c: static const struct bpf_func_proto bpf_redirect_peer_proto =
if (unlikely((plen && plen < sizeof(*params)) || flags))
return TC_ACT_SHOT;
-@@ net/core/filter.c: void xdp_do_check_flushed(struct napi_struct *napi)
+@@ net/core/filter.c: void xdp_do_flush(void)
}
- #endif
+ EXPORT_SYMBOL_GPL(xdp_do_flush);
-void bpf_clear_redirect_map(struct bpf_map *map)
-{
@@ net/core/lwt_bpf.c: static inline struct bpf_lwt *bpf_lwt_lwtunnel(struct lwtunn
+ struct bpf_net_context __bpf_net_ctx, *bpf_net_ctx;
int ret;
- /* Disabling BH is needed to protect per-CPU bpf_redirect_info between
- * BPF prog and skb_do_redirect().
+ /* Migration disable and BH disable are needed to protect per-cpu
+@@ net/core/lwt_bpf.c: static int run_lwt_bpf(struct sk_buff *skb, struct bpf_lwt_prog *lwt,
*/
+ migrate_disable();
local_bh_disable();
+ bpf_net_ctx = bpf_net_ctx_set(&__bpf_net_ctx);
bpf_compute_data_pointers(skb);
@@ net/core/lwt_bpf.c: static int run_lwt_bpf(struct sk_buff *skb, struct bpf_lwt_p
+ bpf_net_ctx_clear(bpf_net_ctx);
local_bh_enable();
+ migrate_enable();
- return ret;
---
Results of testing on various branches:
| Branch | Patch Apply | Build Test |
|---------------------------|-------------|------------|
| stable/linux-6.6.y | Success | Success |
next prev parent reply other threads:[~2025-02-27 5:08 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-02-26 9:39 [PATCH 6.6 v3 0/3] Set the bpf_net_context before invoking BPF XDP in the TUN driver Ricardo Cañuelo Navarro
2025-02-26 9:39 ` [PATCH 6.6 v3 1/3] net: Reference bpf_redirect_info via task_struct on PREEMPT_RT Ricardo Cañuelo Navarro
2025-02-27 5:08 ` Sasha Levin [this message]
2025-02-28 4:56 ` Sasha Levin
2025-02-26 9:39 ` [PATCH 6.6 v3 2/3] tun: Assign missing bpf_net_context Ricardo Cañuelo Navarro
2025-02-27 5:08 ` Sasha Levin
2025-02-28 4:56 ` Sasha Levin
2025-02-26 9:39 ` [PATCH 6.6 v3 3/3] tun: Add missing bpf_net_ctx_clear() in do_xdp_generic() Ricardo Cañuelo Navarro
2025-02-27 5:08 ` Sasha Levin
2025-02-28 4:56 ` Sasha Levin
2025-02-26 16:31 ` [PATCH 6.6 v3 0/3] Set the bpf_net_context before invoking BPF XDP in the TUN driver Sebastian Andrzej Siewior
2025-02-26 17:12 ` Ricardo Cañuelo Navarro
2025-02-27 16:31 ` Sebastian Andrzej Siewior
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