mirror of
https://github.com/hardkernel/linux.git
synced 2026-06-03 09:41:54 +09:00
732b74d647
commit126285651b("Merge ra.kernel.org:/pub/scm/linux/kernel/git/netdev/net") accidentally reverted the effect of commit1a8024239d("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 original1a8024239d("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>
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.