linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	stable@vger.kernel.org, Willem de Bruijn <willemb@google.com>,
	Steffen Klassert <steffen.klassert@secunet.com>,
	Jakub Kicinski <kuba@kernel.org>
Subject: [PATCH 5.4 21/33] esp: avoid unneeded kmap_atomic call
Date: Fri, 22 Jan 2021 15:12:37 +0100	[thread overview]
Message-ID: <20210122135734.441605268@linuxfoundation.org> (raw)
In-Reply-To: <20210122135733.565501039@linuxfoundation.org>

From: Willem de Bruijn <willemb@google.com>

[ Upstream commit 9bd6b629c39e3fa9e14243a6d8820492be1a5b2e ]

esp(6)_output_head uses skb_page_frag_refill to allocate a buffer for
the esp trailer.

It accesses the page with kmap_atomic to handle highmem. But
skb_page_frag_refill can return compound pages, of which
kmap_atomic only maps the first underlying page.

skb_page_frag_refill does not return highmem, because flag
__GFP_HIGHMEM is not set. ESP uses it in the same manner as TCP.
That also does not call kmap_atomic, but directly uses page_address,
in skb_copy_to_page_nocache. Do the same for ESP.

This issue has become easier to trigger with recent kmap local
debugging feature CONFIG_DEBUG_KMAP_LOCAL_FORCE_MAP.

Fixes: cac2661c53f3 ("esp4: Avoid skb_cow_data whenever possible")
Fixes: 03e2a30f6a27 ("esp6: Avoid skb_cow_data whenever possible")
Signed-off-by: Willem de Bruijn <willemb@google.com>
Acked-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 net/ipv4/esp4.c |    7 +------
 net/ipv6/esp6.c |    7 +------
 2 files changed, 2 insertions(+), 12 deletions(-)

--- a/net/ipv4/esp4.c
+++ b/net/ipv4/esp4.c
@@ -272,7 +272,6 @@ static int esp_output_udp_encap(struct x
 int esp_output_head(struct xfrm_state *x, struct sk_buff *skb, struct esp_info *esp)
 {
 	u8 *tail;
-	u8 *vaddr;
 	int nfrags;
 	int esph_offset;
 	struct page *page;
@@ -314,14 +313,10 @@ int esp_output_head(struct xfrm_state *x
 			page = pfrag->page;
 			get_page(page);
 
-			vaddr = kmap_atomic(page);
-
-			tail = vaddr + pfrag->offset;
+			tail = page_address(page) + pfrag->offset;
 
 			esp_output_fill_trailer(tail, esp->tfclen, esp->plen, esp->proto);
 
-			kunmap_atomic(vaddr);
-
 			nfrags = skb_shinfo(skb)->nr_frags;
 
 			__skb_fill_page_desc(skb, nfrags, page, pfrag->offset,
--- a/net/ipv6/esp6.c
+++ b/net/ipv6/esp6.c
@@ -226,7 +226,6 @@ static void esp_output_fill_trailer(u8 *
 int esp6_output_head(struct xfrm_state *x, struct sk_buff *skb, struct esp_info *esp)
 {
 	u8 *tail;
-	u8 *vaddr;
 	int nfrags;
 	struct page *page;
 	struct sk_buff *trailer;
@@ -259,14 +258,10 @@ int esp6_output_head(struct xfrm_state *
 			page = pfrag->page;
 			get_page(page);
 
-			vaddr = kmap_atomic(page);
-
-			tail = vaddr + pfrag->offset;
+			tail = page_address(page) + pfrag->offset;
 
 			esp_output_fill_trailer(tail, esp->tfclen, esp->plen, esp->proto);
 
-			kunmap_atomic(vaddr);
-
 			nfrags = skb_shinfo(skb)->nr_frags;
 
 			__skb_fill_page_desc(skb, nfrags, page, pfrag->offset,



  parent reply	other threads:[~2021-01-22 14:28 UTC|newest]

Thread overview: 40+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-01-22 14:12 [PATCH 5.4 00/33] 5.4.92-rc1 review Greg Kroah-Hartman
2021-01-22 14:12 ` [PATCH 5.4 01/33] usb: ohci: Make distrust_firmware param default to false Greg Kroah-Hartman
2021-01-22 14:12 ` [PATCH 5.4 02/33] compiler.h: Raise minimum version of GCC to 5.1 for arm64 Greg Kroah-Hartman
2021-01-22 14:12 ` [PATCH 5.4 03/33] xen/privcmd: allow fetching resource sizes Greg Kroah-Hartman
2021-01-22 14:12 ` [PATCH 5.4 04/33] elfcore: fix building with clang Greg Kroah-Hartman
2021-01-22 14:12 ` [PATCH 5.4 05/33] scsi: lpfc: Make function lpfc_defer_pt2pt_acc static Greg Kroah-Hartman
2021-01-22 14:12 ` [PATCH 5.4 06/33] scsi: lpfc: Make lpfc_defer_acc_rsp static Greg Kroah-Hartman
2021-01-22 14:12 ` [PATCH 5.4 07/33] spi: npcm-fiu: simplify the return expression of npcm_fiu_probe() Greg Kroah-Hartman
2021-01-22 14:12 ` [PATCH 5.4 08/33] spi: npcm-fiu: Disable clock in probe error path Greg Kroah-Hartman
2021-01-22 14:12 ` [PATCH 5.4 09/33] nfsd4: readdirplus shouldnt return parent of export Greg Kroah-Hartman
2021-01-22 14:12 ` [PATCH 5.4 10/33] bpf: Dont leak memory in bpf getsockopt when optlen == 0 Greg Kroah-Hartman
2021-01-22 14:12 ` [PATCH 5.4 11/33] bpf: Fix helper bpf_map_peek_elem_proto pointing to wrong callback Greg Kroah-Hartman
2021-01-22 14:12 ` [PATCH 5.4 12/33] udp: Prevent reuseport_select_sock from reading uninitialized socks Greg Kroah-Hartman
2021-01-22 14:12 ` [PATCH 5.4 13/33] netxen_nic: fix MSI/MSI-x interrupts Greg Kroah-Hartman
2021-01-22 14:12 ` [PATCH 5.4 14/33] net: introduce skb_list_walk_safe for skb segment walking Greg Kroah-Hartman
2021-01-22 14:12 ` [PATCH 5.4 15/33] net: skbuff: disambiguate argument and member for skb_list_walk_safe helper Greg Kroah-Hartman
2021-01-22 14:12 ` [PATCH 5.4 16/33] net: ipv6: Validate GSO SKB before finish IPv6 processing Greg Kroah-Hartman
2021-01-22 14:12 ` [PATCH 5.4 17/33] mlxsw: core: Add validation of transceiver temperature thresholds Greg Kroah-Hartman
2021-01-22 14:12 ` [PATCH 5.4 18/33] mlxsw: core: Increase critical threshold for ASIC thermal zone Greg Kroah-Hartman
2021-01-22 14:12 ` [PATCH 5.4 19/33] net: mvpp2: Remove Pause and Asym_Pause support Greg Kroah-Hartman
2021-01-22 14:12 ` [PATCH 5.4 20/33] rndis_host: set proper input size for OID_GEN_PHYSICAL_MEDIUM request Greg Kroah-Hartman
2021-01-22 14:12 ` Greg Kroah-Hartman [this message]
2021-01-22 14:12 ` [PATCH 5.4 22/33] net: dcb: Validate netlink message in DCB handler Greg Kroah-Hartman
2021-01-22 14:12 ` [PATCH 5.4 23/33] net: dcb: Accept RTM_GETDCB messages carrying set-like DCB commands Greg Kroah-Hartman
2021-01-22 14:12 ` [PATCH 5.4 24/33] rxrpc: Call state should be read with READ_ONCE() under some circumstances Greg Kroah-Hartman
2021-01-22 14:12 ` [PATCH 5.4 25/33] net: stmmac: Fixed mtu channged by cache aligned Greg Kroah-Hartman
2021-01-22 14:12 ` [PATCH 5.4 26/33] net: sit: unregister_netdevice on newlinks error path Greg Kroah-Hartman
2021-01-22 14:12 ` [PATCH 5.4 27/33] net: avoid 32 x truesize under-estimation for tiny skbs Greg Kroah-Hartman
2021-01-22 14:12 ` [PATCH 5.4 28/33] rxrpc: Fix handling of an unsupported token type in rxrpc_read() Greg Kroah-Hartman
2021-01-22 14:12 ` [PATCH 5.4 29/33] net, sctp, filter: remap copy_from_user failure error Greg Kroah-Hartman
2021-01-22 16:55   ` Marcelo Ricardo Leitner
2021-01-23 14:57     ` Greg Kroah-Hartman
2021-01-22 14:12 ` [PATCH 5.4 30/33] tipc: fix NULL deref in tipc_link_xmit() Greg Kroah-Hartman
2021-01-22 14:12 ` [PATCH 5.4 31/33] mac80211: do not drop tx nulldata packets on encrypted links Greg Kroah-Hartman
2021-01-22 14:12 ` [PATCH 5.4 32/33] mac80211: check if atf has been disabled in __ieee80211_schedule_txq Greg Kroah-Hartman
2021-01-22 14:12 ` [PATCH 5.4 33/33] spi: cadence: cache reference clock rate during probe Greg Kroah-Hartman
2021-01-23  0:24 ` [PATCH 5.4 00/33] 5.4.92-rc1 review Shuah Khan
2021-01-23  5:57 ` Naresh Kamboju
2021-01-23  7:20   ` Naresh Kamboju
2021-01-23 14:35 ` Guenter Roeck

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20210122135734.441605268@linuxfoundation.org \
    --to=gregkh@linuxfoundation.org \
    --cc=kuba@kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=stable@vger.kernel.org \
    --cc=steffen.klassert@secunet.com \
    --cc=willemb@google.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).