| Message ID | 20240308152723.831620-1-dtatulea@nvidia.com (mailing list archive) |
|---|---|
| State | Awaiting Upstream |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | [net,v3] net: esp: fix bad handling of pages from page_pool | expand |
Hi Dragos, On Fri, 8 Mar 2024 at 17:27, Dragos Tatulea <dtatulea@nvidia.com> wrote: > > 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. > Indeed if you call put_page, you will leak a page. But won't that skb eventually be freed by skb_free_head()? Thanks /Ilias > 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> > --- > Changes in v2: > - Fixes in tags. > > Changes in v3: > - Rebased to ipsec tree. > --- > include/linux/skbuff.h | 10 ++++++++++ > net/ipv4/esp4.c | 8 ++++---- > net/ipv6/esp6.c | 8 ++++---- > 3 files changed, 18 insertions(+), 8 deletions(-) > > diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h > index 2dde34c29203..d9a1ccfb5708 100644 > --- a/include/linux/skbuff.h > +++ b/include/linux/skbuff.h > @@ -3448,6 +3448,16 @@ static inline void skb_frag_ref(struct sk_buff *skb, int f) > > 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); > -- > 2.42.0 >
Hi Ilias, On Mon, 2024-03-11 at 10:43 +0200, Ilias Apalodimas wrote: > Hi Dragos, > > On Fri, 8 Mar 2024 at 17:27, Dragos Tatulea <dtatulea@nvidia.com> wrote: > > > > 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. > > > > Indeed if you call put_page, you will leak a page. But won't that skb > eventually be freed by skb_free_head()? > I don't think it will: if you look at esp_output_tail (!esp->inplace case), the skb frags are put on the sg list and then the skb is cut off to have a single frag (with a "regular" page from x->xfrag). So if the pages from the old fragments are not freed here they will leak altogether. Thanks, Dragos > Thanks > /Ilias > > > 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> > > --- > > Changes in v2: > > - Fixes in tags. > > > > Changes in v3: > > - Rebased to ipsec tree. > > --- > > include/linux/skbuff.h | 10 ++++++++++ > > net/ipv4/esp4.c | 8 ++++---- > > net/ipv6/esp6.c | 8 ++++---- > > 3 files changed, 18 insertions(+), 8 deletions(-) > > > > diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h > > index 2dde34c29203..d9a1ccfb5708 100644 > > --- a/include/linux/skbuff.h > > +++ b/include/linux/skbuff.h > > @@ -3448,6 +3448,16 @@ static inline void skb_frag_ref(struct sk_buff *skb, int f) > > > > 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); > > -- > > 2.42.0 > >
Hi Dragos On Mon, 11 Mar 2024 at 10:51, Dragos Tatulea <dtatulea@nvidia.com> wrote: > > Hi Ilias, > > On Mon, 2024-03-11 at 10:43 +0200, Ilias Apalodimas wrote: > > Hi Dragos, > > > > On Fri, 8 Mar 2024 at 17:27, Dragos Tatulea <dtatulea@nvidia.com> wrote: > > > > > > 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. > > > > > > > Indeed if you call put_page, you will leak a page. But won't that skb > > eventually be freed by skb_free_head()? > > > I don't think it will: if you look at esp_output_tail (!esp->inplace case), the > skb frags are put on the sg list and then the skb is cut off to have a single > frag (with a "regular" page from x->xfrag). So if the pages from the old > fragments are not freed here they will leak altogether. Ok, if they won't reach that function -- which calls napi_pp_put_page itself, then this looks sane Acked-by: Ilias Apalodimas <ilias.apalodimas@linaro.org> > > Thanks, > Dragos > > > Thanks > > /Ilias > > > > > 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> > > > --- > > > Changes in v2: > > > - Fixes in tags. > > > > > > Changes in v3: > > > - Rebased to ipsec tree. > > > --- > > > include/linux/skbuff.h | 10 ++++++++++ > > > net/ipv4/esp4.c | 8 ++++---- > > > net/ipv6/esp6.c | 8 ++++---- > > > 3 files changed, 18 insertions(+), 8 deletions(-) > > > > > > diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h > > > index 2dde34c29203..d9a1ccfb5708 100644 > > > --- a/include/linux/skbuff.h > > > +++ b/include/linux/skbuff.h > > > @@ -3448,6 +3448,16 @@ static inline void skb_frag_ref(struct sk_buff *skb, int f) > > > > > > 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); > > > -- > > > 2.42.0 > > > >
On Fri, Mar 08, 2024 at 05:26:00PM +0200, Dragos Tatulea wrote: > 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: ... > 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> Applied to the ipsec tree, thanks a lot!
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 2dde34c29203..d9a1ccfb5708 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -3448,6 +3448,16 @@ static inline void skb_frag_ref(struct sk_buff *skb, int f) 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);
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> --- Changes in v2: - Fixes in tags. Changes in v3: - Rebased to ipsec tree. --- include/linux/skbuff.h | 10 ++++++++++ net/ipv4/esp4.c | 8 ++++---- net/ipv6/esp6.c | 8 ++++---- 3 files changed, 18 insertions(+), 8 deletions(-)