diff mbox series

[1/2] net: esp: fix bad handling of pages from page_pool

Message ID 20240319110151.409825-2-steffen.klassert@secunet.com (mailing list archive)
State Accepted
Commit c3198822c6cb9fb588e446540485669cc81c5d34
Delegated to: Netdev Maintainers
Headers show
Series [1/2] net: esp: fix bad handling of pages from page_pool | expand

Checks

Context Check Description
netdev/series_format warning Pull request is its own cover letter; Target tree name not specified in the subject
netdev/tree_selection success Guessed tree name to be net-next
netdev/ynl success Generated files up to date; no warnings/errors; no diff in generated;
netdev/fixes_present success Fixes tag not required for -next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 5778 this patch: 5778
netdev/build_tools success Errors and warnings before: 0 this patch: 0
netdev/cc_maintainers fail 2 blamed authors not CCed: ilias.apalodimas@linaro.org hawk@kernel.org; 5 maintainers not CCed: pabeni@redhat.com hawk@kernel.org ilias.apalodimas@linaro.org edumazet@google.com dsahern@kernel.org
netdev/build_clang success Errors and warnings before: 2061 this patch: 2061
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success Fixes tag looks correct
netdev/build_allmodconfig_warn success Errors and warnings before: 6068 this patch: 6068
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 80 lines checked
netdev/build_clang_rust success No Rust files in patch. Skipping build
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0
netdev/contest success net-next-2024-03-19--18-00 (tests: 907)

Commit Message

Steffen Klassert March 19, 2024, 11:01 a.m. UTC 
From: Dragos Tatulea <dtatulea@nvidia.com>

When the skb is reorganized during esp_output (!esp->inline), the pages
coming from the original skb fragments are supposed to be released back
to the system through put_page. But if the skb fragment pages are
originating from a page_pool, calling put_page on them will trigger a
page_pool leak which will eventually result in a crash.

This leak can be easily observed when using CONFIG_DEBUG_VM and doing
ipsec + gre (non offloaded) forwarding:

  BUG: Bad page state in process ksoftirqd/16  pfn:1451b6
  page:00000000de2b8d32 refcount:0 mapcount:0 mapping:0000000000000000 index:0x1451b6000 pfn:0x1451b6
  flags: 0x200000000000000(node=0|zone=2)
  page_type: 0xffffffff()
  raw: 0200000000000000 dead000000000040 ffff88810d23c000 0000000000000000
  raw: 00000001451b6000 0000000000000001 00000000ffffffff 0000000000000000
  page dumped because: page_pool leak
  Modules linked in: ip_gre gre mlx5_ib mlx5_core xt_conntrack xt_MASQUERADE nf_conntrack_netlink nfnetlink iptable_nat nf_nat xt_addrtype br_netfilter rpcrdma rdma_ucm ib_iser libiscsi scsi_transport_iscsi ib_umad rdma_cm ib_ipoib iw_cm ib_cm ib_uverbs ib_core overlay zram zsmalloc fuse [last unloaded: mlx5_core]
  CPU: 16 PID: 96 Comm: ksoftirqd/16 Not tainted 6.8.0-rc4+ #22
  Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014
  Call Trace:
   <TASK>
   dump_stack_lvl+0x36/0x50
   bad_page+0x70/0xf0
   free_unref_page_prepare+0x27a/0x460
   free_unref_page+0x38/0x120
   esp_ssg_unref.isra.0+0x15f/0x200
   esp_output_tail+0x66d/0x780
   esp_xmit+0x2c5/0x360
   validate_xmit_xfrm+0x313/0x370
   ? validate_xmit_skb+0x1d/0x330
   validate_xmit_skb_list+0x4c/0x70
   sch_direct_xmit+0x23e/0x350
   __dev_queue_xmit+0x337/0xba0
   ? nf_hook_slow+0x3f/0xd0
   ip_finish_output2+0x25e/0x580
   iptunnel_xmit+0x19b/0x240
   ip_tunnel_xmit+0x5fb/0xb60
   ipgre_xmit+0x14d/0x280 [ip_gre]
   dev_hard_start_xmit+0xc3/0x1c0
   __dev_queue_xmit+0x208/0xba0
   ? nf_hook_slow+0x3f/0xd0
   ip_finish_output2+0x1ca/0x580
   ip_sublist_rcv_finish+0x32/0x40
   ip_sublist_rcv+0x1b2/0x1f0
   ? ip_rcv_finish_core.constprop.0+0x460/0x460
   ip_list_rcv+0x103/0x130
   __netif_receive_skb_list_core+0x181/0x1e0
   netif_receive_skb_list_internal+0x1b3/0x2c0
   napi_gro_receive+0xc8/0x200
   gro_cell_poll+0x52/0x90
   __napi_poll+0x25/0x1a0
   net_rx_action+0x28e/0x300
   __do_softirq+0xc3/0x276
   ? sort_range+0x20/0x20
   run_ksoftirqd+0x1e/0x30
   smpboot_thread_fn+0xa6/0x130
   kthread+0xcd/0x100
   ? kthread_complete_and_exit+0x20/0x20
   ret_from_fork+0x31/0x50
   ? kthread_complete_and_exit+0x20/0x20
   ret_from_fork_asm+0x11/0x20
   </TASK>

The suggested fix is to introduce a new wrapper (skb_page_unref) that
covers page refcounting for page_pool pages as well.

Cc: stable@vger.kernel.org
Fixes: 6a5bcd84e886 ("page_pool: Allow drivers to hint on SKB recycling")
Reported-and-tested-by: Anatoli N.Chechelnickiy <Anatoli.Chechelnickiy@m.interpipe.biz>
Reported-by: Ian Kumlien <ian.kumlien@gmail.com>
Link: https://lore.kernel.org/netdev/CAA85sZvvHtrpTQRqdaOx6gd55zPAVsqMYk_Lwh4Md5knTq7AyA@mail.gmail.com
Signed-off-by: Dragos Tatulea <dtatulea@nvidia.com>
Reviewed-by: Mina Almasry <almasrymina@google.com>
Reviewed-by: Jakub Kicinski <kuba@kernel.org>
Acked-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
---
 include/linux/skbuff.h | 10 ++++++++++
 net/ipv4/esp4.c        |  8 ++++----
 net/ipv6/esp6.c        |  8 ++++----
 3 files changed, 18 insertions(+), 8 deletions(-)

Comments

patchwork-bot+netdevbpf@kernel.org March 20, 2024, 3:10 a.m. UTC | #1 
Hello:

This series was applied to netdev/net.git (main)
by Steffen Klassert <steffen.klassert@secunet.com>:

On Tue, 19 Mar 2024 12:01:50 +0100 you wrote:
> From: Dragos Tatulea <dtatulea@nvidia.com>
> 
> When the skb is reorganized during esp_output (!esp->inline), the pages
> coming from the original skb fragments are supposed to be released back
> to the system through put_page. But if the skb fragment pages are
> originating from a page_pool, calling put_page on them will trigger a
> page_pool leak which will eventually result in a crash.
> 
> [...]

Here is the summary with links:
  - [1/2] net: esp: fix bad handling of pages from page_pool
    https://git.kernel.org/netdev/net/c/c3198822c6cb
  - [2/2] xfrm: Allow UDP encapsulation only in offload modes
    https://git.kernel.org/netdev/net/c/773bb766ca4a

You are awesome, thank you!
diff mbox series

Patch

diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index 3023bc2be6a1..b49a7d6591e8 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -3523,6 +3523,16 @@  int skb_cow_data_for_xdp(struct page_pool *pool, struct sk_buff **pskb,
 			 struct bpf_prog *prog);
 bool napi_pp_put_page(struct page *page, bool napi_safe);
 
+static inline void
+skb_page_unref(const struct sk_buff *skb, struct page *page, bool napi_safe)
+{
+#ifdef CONFIG_PAGE_POOL
+	if (skb->pp_recycle && napi_pp_put_page(page, napi_safe))
+		return;
+#endif
+	put_page(page);
+}
+
 static inline void
 napi_frag_unref(skb_frag_t *frag, bool recycle, bool napi_safe)
 {
diff --git a/net/ipv4/esp4.c b/net/ipv4/esp4.c
index 4dd9e5040672..d33d12421814 100644
--- a/net/ipv4/esp4.c
+++ b/net/ipv4/esp4.c
@@ -95,7 +95,7 @@  static inline struct scatterlist *esp_req_sg(struct crypto_aead *aead,
 			     __alignof__(struct scatterlist));
 }
 
-static void esp_ssg_unref(struct xfrm_state *x, void *tmp)
+static void esp_ssg_unref(struct xfrm_state *x, void *tmp, struct sk_buff *skb)
 {
 	struct crypto_aead *aead = x->data;
 	int extralen = 0;
@@ -114,7 +114,7 @@  static void esp_ssg_unref(struct xfrm_state *x, void *tmp)
 	 */
 	if (req->src != req->dst)
 		for (sg = sg_next(req->src); sg; sg = sg_next(sg))
-			put_page(sg_page(sg));
+			skb_page_unref(skb, sg_page(sg), false);
 }
 
 #ifdef CONFIG_INET_ESPINTCP
@@ -260,7 +260,7 @@  static void esp_output_done(void *data, int err)
 	}
 
 	tmp = ESP_SKB_CB(skb)->tmp;
-	esp_ssg_unref(x, tmp);
+	esp_ssg_unref(x, tmp, skb);
 	kfree(tmp);
 
 	if (xo && (xo->flags & XFRM_DEV_RESUME)) {
@@ -639,7 +639,7 @@  int esp_output_tail(struct xfrm_state *x, struct sk_buff *skb, struct esp_info *
 	}
 
 	if (sg != dsg)
-		esp_ssg_unref(x, tmp);
+		esp_ssg_unref(x, tmp, skb);
 
 	if (!err && x->encap && x->encap->encap_type == TCP_ENCAP_ESPINTCP)
 		err = esp_output_tail_tcp(x, skb);
diff --git a/net/ipv6/esp6.c b/net/ipv6/esp6.c
index 6e6efe026cdc..7371886d4f9f 100644
--- a/net/ipv6/esp6.c
+++ b/net/ipv6/esp6.c
@@ -112,7 +112,7 @@  static inline struct scatterlist *esp_req_sg(struct crypto_aead *aead,
 			     __alignof__(struct scatterlist));
 }
 
-static void esp_ssg_unref(struct xfrm_state *x, void *tmp)
+static void esp_ssg_unref(struct xfrm_state *x, void *tmp, struct sk_buff *skb)
 {
 	struct crypto_aead *aead = x->data;
 	int extralen = 0;
@@ -131,7 +131,7 @@  static void esp_ssg_unref(struct xfrm_state *x, void *tmp)
 	 */
 	if (req->src != req->dst)
 		for (sg = sg_next(req->src); sg; sg = sg_next(sg))
-			put_page(sg_page(sg));
+			skb_page_unref(skb, sg_page(sg), false);
 }
 
 #ifdef CONFIG_INET6_ESPINTCP
@@ -294,7 +294,7 @@  static void esp_output_done(void *data, int err)
 	}
 
 	tmp = ESP_SKB_CB(skb)->tmp;
-	esp_ssg_unref(x, tmp);
+	esp_ssg_unref(x, tmp, skb);
 	kfree(tmp);
 
 	esp_output_encap_csum(skb);
@@ -677,7 +677,7 @@  int esp6_output_tail(struct xfrm_state *x, struct sk_buff *skb, struct esp_info
 	}
 
 	if (sg != dsg)
-		esp_ssg_unref(x, tmp);
+		esp_ssg_unref(x, tmp, skb);
 
 	if (!err && x->encap && x->encap->encap_type == TCP_ENCAP_ESPINTCP)
 		err = esp_output_tail_tcp(x, skb);