linux-toradex.git/drivers/connector/cn_proc.c, branch v4.9.34

connector: make cn_proc explicitly non-modular

2016-07-05T18:40:47+00:00

The Kconfig controlling build of this code is currently:

drivers/connector/Kconfig:config PROC_EVENTS
drivers/connector/Kconfig:      bool "Report process events to userspace"

...meaning that it currently is not being built as a module by anyone.
Lets remove the two modular references, so that when reading the driver
there is no doubt it is builtin-only.

Since module_init translates to device_initcall in the non-modular
case, the init ordering remains unchanged with this commit.

Cc: Evgeniy Polyakov 
Cc: netdev@vger.kernel.org
Signed-off-by: Paul Gortmaker 
Signed-off-by: David S. Miller

connector: fix out-of-order cn_proc netlink message delivery

2016-06-28T12:48:33+00:00

The proc connector messages include a sequence number, allowing userspace
programs to detect lost messages.  However, performing this detection is
currently more difficult than necessary, since netlink messages can be
delivered to the application out-of-order.  To fix this, leave pre-emption
disabled during cn_netlink_send(), and use GFP_NOWAIT.

The following was written as a test case.  Building the kernel w/ make -j32
proved a reliable way to generate out-of-order cn_proc messages.

int
main(int argc, char *argv[])
{
	static uint32_t last_seq[CPU_SETSIZE], seq;
	int cpu, fd;
	struct sockaddr_nl sa;
	struct __attribute__((aligned(NLMSG_ALIGNTO))) {
		struct nlmsghdr nl_hdr;
		struct __attribute__((__packed__)) {
			struct cn_msg cn_msg;
			struct proc_event cn_proc;
		};
	} rmsg;
	struct __attribute__((aligned(NLMSG_ALIGNTO))) {
		struct nlmsghdr nl_hdr;
		struct __attribute__((__packed__)) {
			struct cn_msg cn_msg;
			enum proc_cn_mcast_op cn_mcast;
		};
	} smsg;

	fd = socket(PF_NETLINK, SOCK_DGRAM, NETLINK_CONNECTOR);
	if (fd < 0) {
		perror("socket");
	}

	sa.nl_family = AF_NETLINK;
	sa.nl_groups = CN_IDX_PROC;
	sa.nl_pid = getpid();
	if (bind(fd, (struct sockaddr *)&sa, sizeof(sa)) < 0) {
		perror("bind");
	}

	memset(&smsg, 0, sizeof(smsg));
	smsg.nl_hdr.nlmsg_len = sizeof(smsg);
	smsg.nl_hdr.nlmsg_pid = getpid();
	smsg.nl_hdr.nlmsg_type = NLMSG_DONE;
	smsg.cn_msg.id.idx = CN_IDX_PROC;
	smsg.cn_msg.id.val = CN_VAL_PROC;
	smsg.cn_msg.len = sizeof(enum proc_cn_mcast_op);
	smsg.cn_mcast = PROC_CN_MCAST_LISTEN;
	if (send(fd, &smsg, sizeof(smsg), 0) != sizeof(smsg)) {
		perror("send");
	}

	while (recv(fd, &rmsg, sizeof(rmsg), 0) == sizeof(rmsg)) {
		cpu = rmsg.cn_proc.cpu;
		if (cpu < 0) {
			continue;
		}
		seq = rmsg.cn_msg.seq;
		if ((last_seq[cpu] != 0) && (seq != last_seq[cpu] + 1)) {
			printf("out-of-order seq=%d on cpu=%d\n", seq, cpu);
		}
		last_seq[cpu] = seq;
	}

	/* NOTREACHED */

	perror("recv");

	return -1;
}

Signed-off-by: Aaron Campbell 
Signed-off-by: David S. Miller

connector: Use ktime_get_ns()

2014-07-23T17:18:07+00:00

Replace the ever recurring:
        ts = ktime_get_ts();
        ns = timespec_to_ns(&ts);
with
        ns = ktime_get_ns();

Signed-off-by: Thomas Gleixner 
Cc: Evgeniy Polyakov 
Signed-off-by: John Stultz

net: Use netlink_ns_capable to verify the permisions of netlink messages

2014-04-24T17:44:54+00:00

It is possible by passing a netlink socket to a more privileged
executable and then to fool that executable into writing to the socket
data that happens to be valid netlink message to do something that
privileged executable did not intend to do.

To keep this from happening replace bare capable and ns_capable calls
with netlink_capable, netlink_net_calls and netlink_ns_capable calls.
Which act the same as the previous calls except they verify that the
opener of the socket had the desired permissions as well.

Reported-by: Andy Lutomirski 
Signed-off-by: "Eric W. Biederman" 
Signed-off-by: David S. Miller

connector: add portid to unicast in addition to broadcasting

2014-02-07T23:40:17+00:00

This allows replying only to the requestor portid while still
supporting broadcasting.  Pass 0 to portid for the previous behavior.

Signed-off-by: David Fries 
Acked-by: Evgeniy Polyakov 
Signed-off-by: Greg Kroah-Hartman

connector: improved unaligned access error fix

2013-11-14T22:19:20+00:00

In af3e095a1fb4, Erik Jacobsen fixed one type of unaligned access
bug for ia64 by converting a 64-bit write to use put_unaligned().
Unfortunately, since gcc will convert a short memset() to a series
of appropriately-aligned stores, the problem is now visible again
on tilegx, where the memset that zeros out proc_event is converted
to three 64-bit stores, causing an unaligned access panic.

A better fix for the original problem is to ensure that proc_event
is aligned to 8 bytes here.  We can do that relatively easily by
arranging to start the struct cn_msg aligned to 8 bytes and then
offset by 4 bytes.  Doing so means that the immediately following
proc_event structure is then correctly aligned to 8 bytes.

The result is that the memset() stores are now aligned, and as an
added benefit, we can remove the put_unaligned() calls in the code.

Signed-off-by: Chris Metcalf 
Signed-off-by: David S. Miller

proc connector: fix info leaks

2013-10-02T20:03:50+00:00

Initialize event_data for all possible message types to prevent leaking
kernel stack contents to userland (up to 20 bytes). Also set the flags
member of the connector message to 0 to prevent leaking two more stack
bytes this way.

Cc: stable@vger.kernel.org  # v2.6.15+
Signed-off-by: Mathias Krause 
Signed-off-by: David S. Miller

connector: Added coredumping event to the process connector

2013-03-20T17:23:21+00:00

Process connector can now also detect coredumping events.

Main aim of patch is get notified at start of coredumping, instead of
having to wait for it to finish and then being notified through EXIT
event.

Could be used for instance by process-managers that want to get
notified as soon as possible about process failures, and not
necessarily beeing notified after coredump, which could be in the
order of minutes depending on size of coredump, piping and so on.

Signed-off-by: Jesper Derehag 
Signed-off-by: David S. Miller

proc connector: reject unprivileged listener bumps

2013-02-27T18:08:35+00:00

While PROC_CN_MCAST_LISTEN/IGNORE is entirely advisory, it was possible
for an unprivileged user to turn off notifications for all listeners by
sending PROC_CN_MCAST_IGNORE. Instead, require the same privileges as
required for a multicast bind.

Signed-off-by: Kees Cook 
Cc: Evgeniy Polyakov 
Cc: Matt Helsley 
Cc: stable@vger.kernel.org
Acked-by: Evgeniy Polyakov 
Acked-by: Matt Helsley 
Signed-off-by: David S. Miller

userns: Convert process event connector to handle kuids and kgids

2012-09-07T02:37:10+00:00

- Only allow asking for events from the initial user and pid namespace,
  where we generate the events in.

- Convert kuids and kgids into the initial user namespace to report
  them via the process event connector.

Cc: David Miller 
Acked-by: Evgeniy Polyakov 
Acked-by: Serge Hallyn 
Signed-off-by: Eric W. Biederman