Go to file
Xuan Zhuo 732b74d647 virtio-net: fix for skb_over_panic inside big mode
commit 126285651b ("Merge ra.kernel.org:/pub/scm/linux/kernel/git/netdev/net")
accidentally reverted the effect of
commit 1a8024239d ("virtio-net: fix for skb_over_panic inside big mode")
on drivers/net/virtio_net.c

As a result, users of crosvm (which is using large packet mode)
are experiencing crashes with 5.14-rc1 and above that do not
occur with 5.13.

Crash trace:

[   61.346677] skbuff: skb_over_panic: text:ffffffff881ae2c7 len:3762 put:3762 head:ffff8a5ec8c22000 data:ffff8a5ec8c22010 tail:0xec2 end:0xec0 dev:<NULL>
[   61.369192] kernel BUG at net/core/skbuff.c:111!
[   61.372840] invalid opcode: 0000 [#1] SMP PTI
[   61.374892] CPU: 5 PID: 0 Comm: swapper/5 Not tainted 5.14.0-rc1 linux-v5.14-rc1-for-mesa-ci.tar.bz2 #1
[   61.376450] Hardware name: ChromiumOS crosvm, BIOS 0

..

[   61.393635] Call Trace:
[   61.394127]  <IRQ>
[   61.394488]  skb_put.cold+0x10/0x10
[   61.395095]  page_to_skb+0xf7/0x410
[   61.395689]  receive_buf+0x81/0x1660
[   61.396228]  ? netif_receive_skb_list_internal+0x1ad/0x2b0
[   61.397180]  ? napi_gro_flush+0x97/0xe0
[   61.397896]  ? detach_buf_split+0x67/0x120
[   61.398573]  virtnet_poll+0x2cf/0x420
[   61.399197]  __napi_poll+0x25/0x150
[   61.399764]  net_rx_action+0x22f/0x280
[   61.400394]  __do_softirq+0xba/0x257
[   61.401012]  irq_exit_rcu+0x8e/0xb0
[   61.401618]  common_interrupt+0x7b/0xa0
[   61.402270]  </IRQ>

See
https://lore.kernel.org/r/5edaa2b7c2fe4abd0347b8454b2ac032b6694e2c.camel%40collabora.com
for the report.

Apply the original 1a8024239d ("virtio-net: fix for skb_over_panic inside big mode")
again, the original logic still holds:

In virtio-net's large packet mode, there is a hole in the space behind
buf.

    hdr_padded_len - hdr_len

We must take this into account when calculating tailroom.

Cc: Greg KH <gregkh@linuxfoundation.org>
Fixes: fb32856b16 ("virtio-net: page_to_skb() use build_skb when there's sufficient tailroom")
Fixes: 126285651b ("Merge ra.kernel.org:/pub/scm/linux/kernel/git/netdev/net")
Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Reported-by: Corentin Noël <corentin.noel@collabora.com>
Tested-by: Corentin Noël <corentin.noel@collabora.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-10-09 13:50:33 +01:00
arch ARM: dts: spear3xx: Fix gmac node 2021-10-08 16:22:39 +01:00
block block-5.15-2021-10-01 2021-10-02 11:00:36 -07:00
certs certs: Add support for using elliptic curve keys for signing modules 2021-08-23 19:55:42 +03:00
crypto Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 2021-08-30 12:57:10 -07:00
Documentation dt-bindings: net: snps,dwmac: add dwmac 3.40a IP version 2021-10-08 16:22:39 +01:00
drivers virtio-net: fix for skb_over_panic inside big mode 2021-10-09 13:50:33 +01:00
fs Bug fixes for NFSD error handling paths 2021-10-07 14:11:40 -07:00
include net: dsa: mv88e6xxx: isolate the ATU databases of standalone and bridged ports 2021-10-08 15:47:46 -07:00
init Merge branch 'work.init' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2021-09-24 10:18:07 -07:00
ipc ipc: remove memcg accounting for sops objects in do_semtimedop() 2021-09-14 10:22:11 -07:00
kernel Networking fixes for 5.15-rc5, including fixes from xfrm, bpf, 2021-10-07 09:50:31 -07:00
lib lib/zlib_inflate/inffast: check config in C to avoid unused function warning 2021-09-24 16:13:35 -07:00
LICENSES LICENSES/dual/CC-BY-4.0: Git rid of "smart quotes" 2021-07-15 06:31:24 -06:00
mm mm: fix uninitialized use in overcommit_policy_handler 2021-09-24 16:13:35 -07:00
net net: dsa: hold rtnl_lock in dsa_switch_setup_tag_protocol 2021-10-09 13:44:05 +01:00
samples samples/bpf: Relicense bpf_insn.h as GPL-2.0-only OR BSD-2-Clause 2021-09-29 16:03:55 +02:00
scripts kasan: always respect CONFIG_KASAN_STACK 2021-09-24 16:13:35 -07:00
security Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ 2021-10-07 12:44:41 +01:00
sound ALSA: pcsp: Make hrtimer forwarding more robust 2021-09-28 10:58:08 +02:00
tools perf tools fixes for v5.15: 3rd batch 2021-10-07 10:58:42 -07:00
usr .gitignore: prefix local generated files with a slash 2021-05-02 00:43:35 +09:00
virt KVM: Remove tlbs_dirty 2021-09-23 11:01:12 -04:00
.clang-format clang-format: Update with the latest for_each macro list 2021-05-12 23:32:39 +02:00
.cocciconfig
.get_maintainer.ignore Opt out of scripts/get_maintainer.pl 2019-05-16 10:53:40 -07:00
.gitattributes .gitattributes: use 'dts' diff driver for dts files 2019-12-04 19:44:11 -08:00
.gitignore .gitignore: ignore only top-level modules.builtin 2021-05-02 00:43:35 +09:00
.mailmap mailmap: update email address of Matthias Fuchs and Thomas Körper 2021-08-19 09:39:44 +02:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS MAINTAINERS: Move Daniel Drake to credits 2021-09-21 08:34:58 +03:00
Kbuild kbuild: rename hostprogs-y/always to hostprogs/always-y 2020-02-04 01:53:07 +09:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS net: dsa: mv88e6xxx: isolate the ATU databases of standalone and bridged ports 2021-10-08 15:47:46 -07:00
Makefile Linux 5.15-rc4 2021-10-03 14:08:47 -07:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.