No description
  • C 98.2%
  • Assembly 1%
  • Makefile 0.3%
  • Shell 0.2%
  • Python 0.1%
Find a file
Repository files (latest commit first)
Filename Latest commit message Latest commit date
Oleg Nesterov 1f3aa3e028 ipc/mqueue.c: change __do_notify() to bypass check_kill_permission()
commit b5f2006144c6ae941726037120fa1001ddede784 upstream.

Commit cc731525f2 ("signal: Remove kernel interal si_code magic")
changed the value of SI_FROMUSER(SI_MESGQ), this means that mq_notify() no
longer works if the sender doesn't have rights to send a signal.

Change __do_notify() to use do_send_sig_info() instead of kill_pid_info()
to avoid check_kill_permission().

This needs the additional notify.sigev_signo != 0 check, shouldn't we
change do_mq_notify() to deny sigev_signo == 0 ?

Test-case:

	#include <signal.h>
	#include <mqueue.h>
	#include <unistd.h>
	#include <sys/wait.h>
	#include <assert.h>

	static int notified;

	static void sigh(int sig)
	{
		notified = 1;
	}

	int main(void)
	{
		signal(SIGIO, sigh);

		int fd = mq_open("/mq", O_RDWR|O_CREAT, 0666, NULL);
		assert(fd >= 0);

		struct sigevent se = {
			.sigev_notify	= SIGEV_SIGNAL,
			.sigev_signo	= SIGIO,
		};
		assert(mq_notify(fd, &se) == 0);

		if (!fork()) {
			assert(setuid(1) == 0);
			mq_send(fd, "",1,0);
			return 0;
		}

		wait(NULL);
		mq_unlink("/mq");
		assert(notified);
		return 0;
	}

[manfred@colorfullife.com: 1) Add self_exec_id evaluation so that the implementation matches do_notify_parent 2) use PIDTYPE_TGID everywhere]
Fixes: cc731525f2 ("signal: Remove kernel interal si_code magic")
Reported-by: Yoji <yoji.fujihar.min@gmail.com>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Manfred Spraul <manfred@colorfullife.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Markus Elfring <elfring@users.sourceforge.net>
Cc: <1vier1@web.de>
Cc: <stable@vger.kernel.org>
Link: http://lkml.kernel.org/r/e2a782e4-eab9-4f5c-c749-c07a8f7a4e66@colorfullife.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-14 07:58:26 +02:00
arch arm64: hugetlb: avoid potential NULL dereference 2020-05-14 07:58:26 +02:00
block
certs
crypto
Documentation
drivers drm: ingenic-drm: add MODULE_DEVICE_TABLE 2020-05-14 07:58:26 +02:00
fs cifs: do not share tcons with DFS 2020-05-10 10:31:27 +02:00
include tunnel: Propagate ECT(1) when decapsulating as recommended by RFC6040 2020-05-14 07:58:22 +02:00
init
ipc ipc/mqueue.c: change __do_notify() to bypass check_kill_permission() 2020-05-14 07:58:26 +02:00
kernel tracing: Add a vmalloc_sync_mappings() for safe measure 2020-05-14 07:58:25 +02:00
lib lib: devres: add a helper function for ioremap_uc 2020-05-10 10:31:30 +02:00
LICENSES
mm mm/mremap: Add comment explaining the untagging behaviour of mremap() 2020-05-10 10:31:33 +02:00
net sctp: Fix bundling of SHUTDOWN with COOKIE-ACK 2020-05-14 07:58:24 +02:00
samples
scripts scripts/config: allow colons in option strings for sed 2020-05-10 10:31:27 +02:00
security selinux: properly handle multiple messages in selinux_netlink_send() 2020-05-06 08:15:17 +02:00
sound ALSA: hda: Match both PCI ID and SSID for driver blacklist 2020-05-10 10:31:31 +02:00
tools tools headers UAPI: Sync copy of arm64's asm/unistd.h with the kernel sources 2020-05-10 10:31:33 +02:00
usr
virt KVM: arm64: Fix 32bit PC wrap-around 2020-05-14 07:58:26 +02:00
.clang-format
.cocciconfig
.get_maintainer.ignore
.gitattributes
.gitignore
.mailmap
COPYING
CREDITS
Kbuild
Kconfig
MAINTAINERS
Makefile Linux 5.4.40 2020-05-10 10:31:34 +02:00
README

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.