mainlining shenanigans
Go to file
David Howells 555df336c7 keys: Fix description size
The maximum key description size is 4095.  Commit f771fde820 ("keys:
Simplify key description management") inadvertantly reduced that to 255
and made sizes between 256 and 4095 work weirdly, and any size whereby
size & 255 == 0 would cause an assertion in __key_link_begin() at the
following line:

	BUG_ON(index_key->desc_len == 0);

This can be fixed by simply increasing the size of desc_len in struct
keyring_index_key to a u16.

Note the argument length test in keyutils only checked empty
descriptions and descriptions with a size around the limit (ie.  4095)
and not for all the values in between, so it missed this.  This has been
addressed and

	https://git.kernel.org/pub/scm/linux/kernel/git/dhowells/keyutils.git/commit/?id=066bf56807c26cd3045a25f355b34c1d8a20a5aa

now exhaustively tests all possible lengths of type, description and
payload and then some.

The assertion failure looks something like:

 kernel BUG at security/keys/keyring.c:1245!
 ...
 RIP: 0010:__key_link_begin+0x88/0xa0
 ...
 Call Trace:
  key_create_or_update+0x211/0x4b0
  __x64_sys_add_key+0x101/0x200
  do_syscall_64+0x5b/0x1e0
  entry_SYSCALL_64_after_hwframe+0x44/0xa9

It can be triggered by:

	keyctl add user "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa" a @s

Fixes: f771fde820 ("keys: Simplify key description management")
Reported-by: kernel test robot <rong.a.chen@intel.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-08-19 09:43:57 -07:00
arch Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2019-08-18 09:45:42 -07:00
block block: remove REQ_NOWAIT_INLINE 2019-08-15 11:09:16 -06:00
certs Revert "Merge tag 'keys-acl-20190703' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs" 2019-07-10 18:43:43 -07:00
crypto USB / PHY patches for 5.3-rc1 2019-07-11 15:40:06 -07:00
Documentation Devicetree fixes for 5.3: 2019-08-15 09:18:56 -07:00
drivers This pull request contains a single fix for MTD: 2019-08-18 12:56:42 -07:00
fs for-5.3-rc4-tag 2019-08-18 09:51:48 -07:00
include keys: Fix description size 2019-08-19 09:43:57 -07:00
init Merge branch 'work.mount0' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2019-07-19 10:42:02 -07:00
ipc Merge branch 'work.mount0' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2019-07-19 10:42:02 -07:00
kernel SPDX fixes for 5.3-rc5 2019-08-18 09:26:16 -07:00
lib Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2019-08-06 17:11:59 -07:00
LICENSES LICENSES: Rename other to deprecated 2019-05-03 06:34:32 -06:00
mm hugetlbfs: fix hugetlb page migration/fault race causing SIGBUS 2019-08-13 16:06:53 -07:00
net net: dsa: sja1105: Fix memory leak on meta state machine error path 2019-08-06 14:37:02 -07:00
samples auxdisplay: Fix a typo in cfag12864b-example.c 2019-08-08 20:00:18 +02:00
scripts SPDX fixes for 5.3-rc5 2019-08-18 09:26:16 -07:00
security KEYS: trusted: allow module init if TPM is inactive or deactivated 2019-08-13 19:59:23 +03:00
sound sound fixes for 5.3-rc5 2019-08-16 08:49:45 -07:00
tools - A few fixes for the userspace hyper-v tools from Adrian Vladu. 2019-08-17 19:31:30 -07:00
usr kbuild: enable arch/s390/include/uapi/asm/zcrypt.h for uapi header test 2019-07-23 10:45:46 +02:00
virt KVM/arm fixes for 5.3, take #2 2019-08-09 16:53:50 +02:00
.clang-format Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2019-04-17 11:26:25 -07:00
.cocciconfig
.get_maintainer.ignore Opt out of scripts/get_maintainer.pl 2019-05-16 10:53:40 -07:00
.gitattributes .gitattributes: set git diff driver for C source code files 2016-10-07 18:46:30 -07:00
.gitignore .gitignore: Add compilation database file 2019-07-27 12:18:19 +09:00
.mailmap MAINTAINERS: Update my email address 2019-07-22 14:57:50 +01:00
COPYING COPYING: use the new text with points to the license files 2018-03-23 12:41:45 -06:00
CREDITS Remove references to dead website. 2019-07-19 12:22:04 -07:00
Kbuild Kbuild updates for v5.1 2019-03-10 17:48:21 -07:00
Kconfig docs: kbuild: convert docs to ReST and rename to *.rst 2019-06-14 14:21:21 -06:00
MAINTAINERS Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2019-08-18 09:45:42 -07:00
Makefile Linux 5.3-rc5 2019-08-18 14:31:08 -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.