Otherwise recent WDK binaries fail on ARM64, where an exception handler
is used for trapping an illegal instruction when ARMv8.1 atomics are
being tested for functionality.
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
The reason this was failing before is that dloadsup.h's
DloadObtainSection was doing a linear search of sections to find which
header corresponds with the IMAGE_DELAYLOAD_DESCRIPTOR section, and we
were stupidly overwriting the VirtualSize field, so the linear search
wound up matching the .text section, which then it found to not be
marked writable and failed with FAST_FAIL_DLOAD_PROTECTION_FAILURE.
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Probably a bad idea, but we don't currently support it, and those huge
windows.NewCallback trampolines make juicer targets anyway.
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Trying this for every peer winds up being very slow and precludes it
from acceptable runtime in the CI, so reduce this to 4.
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Now that we have parent pointers hooked up, we can simply go right to
the node and remove it in place, rather than having to recursively walk
the entire trie.
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
This makes the insertion algorithm a bit more efficient, while also now
taking on the additional task of connecting up parent pointers. This
will be handy in the following commit.
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Heavier network extensions might require the wireguard-go component to
use less ram, so let users of this reduce these as needed.
At some point we'll put this behind a configuration method of sorts, but
for now, just expose the consts as vars.
Requested-by: Josh Bleecher Snyder <josh@tailscale.com>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
On Linux we can run `ip link del wg0`, in which case the fd becomes
stale, and we should exit. Since this is an intentional action, don't
treat it as an error.
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
The -1 protection was removed and the wrong error was returned, causing
us to read from a bogus fd. As well, remove the useless closures that
aren't doing anything, since this is all synchronized anyway.
Fixes: 10533c3 ("all: make conn.Bind.Open return a slice of receive functions")
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
When retrying, if count is not 0, we forget to dequeue another request,
and so the ring fills up and errors out.
Reported-by: Sascha Dierberg <dierberg@dresearch-fe.de>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
In 097af6e ("tun: windows: protect reads from closing") we made sure no
functions are running when End() is called, to avoid a UaF. But we still
need to kick that event somehow, so that Read() is allowed to exit, in
order to release the lock. So this commit calls SetEvent, while moving
the closing boolean to be atomic so it can be modified without locks,
and then moves to a WaitGroup for the RCU-like pattern.
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
When debugging, it's useful to know why a receive func exited.
We were already logging that, but only in the "death spiral" case.
Move the logging up, to capture it always.
Reduce the verbosity, since it is not an error case any more.
Put the receive func name in the log line.
Signed-off-by: Josh Bleecher Snyder <josharian@gmail.com>
The code previously used the old errors channel for checking, rather
than the simpler boolean, which caused issues on shutdown, since the
errors channel was meaningless. However, looking at this exposed a more
basic problem: Close() and all the other functions that check the closed
boolean can race. So protect with a basic RW lock, to ensure that
Close() waits for all pending operations to complete.
Reported-by: Joshua Sjoding <joshua.sjoding@scjalliance.com>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
If we receive a large UDP packet, don't return an error to receive.go,
which then terminates the receive loop. Instead, simply retry.
Considering Winsock's general finickiness, we might consider other
places where an attacker on the wire can generate error conditions like
this.
Reported-by: Sascha Dierberg <sascha.dierberg@gmail.com>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
When we pass the TUN FD to the child, we have to call TUNSIFPID;
otherwise when we close the device, we get a splat in dmesg.
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Note: this bug is "hidden" by avoiding "death spiral" code path by
6228659 ("device: handle broader range of errors in RoutineReceiveIncoming").
If the code reached "death spiral" mechanism, there would be multiple
double frees happening. This results in a deadlock on iOS, because the
pools are fixed size and goroutine might stop until somebody makes
space in the pool.
This was almost 100% repro on the new ARM Macbooks:
- Build with 'ios' tag for Mac. This will enable bounded pools.
- Somehow call device.IpcSet at least couple of times (update config)
- device.BindUpdate() would be triggered
- RoutineReceiveIncoming would enter "death spiral".
- RoutineReceiveIncoming would stall on double free (pool is already
full)
- The stuck routine would deadlock 'device.closeBindLocked()' function
on line 'netc.stopping.Wait()'
Signed-off-by: Kristupas Antanavičius <kristupas.antanavicius@nordsec.com>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
By not comparing these with the modulo, the ring became nearly never
full, resulting in completion queue buffers filling up prematurely.
Reported-by: Joshua Sjoding <joshua.sjoding@scjalliance.com>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
