mirror of
https://github.com/hardkernel/linux.git
synced 2026-06-04 18:19:28 +09:00
9e39394fae
For IPV6_2292PKTOPTIONS, do_ipv6_getsockopt() stores the user pointer
optval in the msg_control field of the msghdr.
Hence, sparse rightfully warns at ./net/ipv6/ipv6_sockglue.c:1151:33:
warning: incorrect type in assignment (different address spaces)
expected void *msg_control
got char [noderef] __user *optval
Since commit 1f466e1f15 ("net: cleanly handle kernel vs user buffers for
->msg_control"), user pointers shall be stored in the msg_control_user
field, and kernel pointers in the msg_control field. This allows to
propagate __user annotations nicely through this struct.
Store optval in msg_control_user to properly record and propagate the
memory space annotation of this pointer.
Note that msg_control_is_user is set to true, so the key invariant, i.e.,
use msg_control_user if and only if msg_control_is_user is true, holds.
The msghdr is further used in the six alternative put_cmsg() calls, with
msg_control_is_user being true, put_cmsg() picks msg_control_user
preserving the __user annotation and passes that properly to
copy_to_user().
No functional change. No change in object code.
Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20201127093421.21673-1-lukas.bulwahn@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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.