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Zha Bin 7fbe078c37 vhost/vsock: fix vhost vsock cid hashing inconsistent
The vsock core only supports 32bit CID, but the Virtio-vsock spec define
CID (dst_cid and src_cid) as u64 and the upper 32bits is reserved as
zero. This inconsistency causes one bug in vhost vsock driver. The
scenarios is:

  0. A hash table (vhost_vsock_hash) is used to map an CID to a vsock
  object. And hash_min() is used to compute the hash key. hash_min() is
  defined as:
  (sizeof(val) <= 4 ? hash_32(val, bits) : hash_long(val, bits)).
  That means the hash algorithm has dependency on the size of macro
  argument 'val'.
  0. In function vhost_vsock_set_cid(), a 64bit CID is passed to
  hash_min() to compute the hash key when inserting a vsock object into
  the hash table.
  0. In function vhost_vsock_get(), a 32bit CID is passed to hash_min()
  to compute the hash key when looking up a vsock for an CID.

Because the different size of the CID, hash_min() returns different hash
key, thus fails to look up the vsock object for an CID.

To fix this bug, we keep CID as u64 in the IOCTLs and virtio message
headers, but explicitly convert u64 to u32 when deal with the hash table
and vsock core.

Fixes: 834e772c8d ("vhost/vsock: fix use-after-free in network stack callers")
Link: https://github.com/stefanha/virtio/blob/vsock/trunk/content.tex
Signed-off-by: Zha Bin <zhabin@linux.alibaba.com>
Reviewed-by: Liu Jiang <gerry@linux.alibaba.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-01-11 17:48:11 -08:00
arch Remove 'type' argument from access_ok() function 2019-01-03 18:57:57 -08:00
block for-4.21/block-20190102 2019-01-02 18:49:58 -08:00
certs export.h: remove VMLINUX_SYMBOL() and VMLINUX_SYMBOL_STR() 2018-08-22 23:21:44 +09:00
crypto Kconfig updates for v4.21 2018-12-29 13:03:29 -08:00
Documentation bpf, doc: update design qa to reflect kern_version requirement 2019-01-07 15:52:00 -08:00
drivers vhost/vsock: fix vhost vsock cid hashing inconsistent 2019-01-11 17:48:11 -08:00
firmware firmware: refactor firmware/Makefile 2018-12-23 10:10:32 +09:00
fs Remove 'type' argument from access_ok() function 2019-01-03 18:57:57 -08:00
include ptp: uapi: change _IOW to IOWR in PTP_SYS_OFFSET_EXTENDED definition 2019-01-08 16:22:56 -05:00
init Merge tag 'devicetree-for-4.21' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux 2018-12-28 20:08:34 -08:00
ipc ipc: IPCMNI limit check for semmni 2018-10-31 08:54:14 -07:00
kernel bpf: fix bpffs bitfield pretty print 2019-01-11 10:40:54 +01:00
lib Remove 'type' argument from access_ok() function 2019-01-03 18:57:57 -08:00
LICENSES This is a fairly typical cycle for documentation. There's some welcome 2018-10-24 18:01:11 +01:00
mm Remove 'type' argument from access_ok() function 2019-01-03 18:57:57 -08:00
net Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf 2019-01-11 12:51:49 -08:00
samples samples: bpf: user proper argument index 2019-01-10 15:54:47 +01:00
scripts Tracing changes for v4.21: 2018-12-31 11:46:59 -08:00
security Remove 'type' argument from access_ok() function 2019-01-03 18:57:57 -08:00
sound Remove 'type' argument from access_ok() function 2019-01-03 18:57:57 -08:00
tools tools/bpf: fix bpftool map dump with bitfields 2019-01-11 10:40:54 +01:00
usr user/Makefile: Fix typo and capitalization in comment section 2018-12-11 00:18:03 +09:00
virt Remove 'type' argument from access_ok() function 2019-01-03 18:57:57 -08:00
.clang-format page cache: Convert find_get_pages_contig to XArray 2018-10-21 10:46:34 -04:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.get_maintainer.ignore
.gitattributes .gitattributes: set git diff driver for C source code files 2016-10-07 18:46:30 -07:00
.gitignore kbuild: Add support for DT binding schema checks 2018-12-13 09:41:32 -06:00
.mailmap Merge tag 'nand/for-4.21' of git://git.infradead.org/linux-mtd into mtd/next 2018-12-18 19:59:16 +01:00
COPYING COPYING: use the new text with points to the license files 2018-03-23 12:41:45 -06:00
CREDITS MAINTAINERS: update entry for MMP platform 2018-12-03 12:39:57 -08:00
Kbuild kbuild: remove unused cmd_gentimeconst 2018-12-25 00:10:30 +09:00
Kconfig kconfig: move the "Executable file formats" menu to fs/Kconfig.binfmt 2018-08-02 08:06:55 +09:00
MAINTAINERS Merge branch 'for-linus-4.21-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml 2019-01-02 18:39:22 -08:00
Makefile Kbuild updates for v4.21 2018-12-29 12:03:17 -08:00
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.