linux-stable.git/drivers/char, branch v3.16.67

tty: mark Siemens R3964 line discipline as BROKEN

2019-05-02T20:42:07+00:00

commit c7084edc3f6d67750f50d4183134c4fb5712a5c8 upstream.

The n_r3964 line discipline driver was written in a different time, when
SMP machines were rare, and users were trusted to do the right thing.
Since then, the world has moved on but not this code, it has stayed
rooted in the past with its lovely hand-crafted list structures and
loads of "interesting" race conditions all over the place.

After attempting to clean up most of the issues, I just gave up and am
now marking the driver as BROKEN so that hopefully someone who has this
hardware will show up out of the woodwork (I know you are out there!)
and will help with debugging a raft of changes that I had laying around
for the code, but was too afraid to commit as odds are they would break
things.

Many thanks to Jann and Linus for pointing out the initial problems in
this codebase, as well as many reviews of my attempts to fix the issues.
It was a case of whack-a-mole, and as you can see, the mole won.

Reported-by: Jann Horn 
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Linus Torvalds 
Signed-off-by: Ben Hutchings

ipmi: msghandler: Fix potential Spectre v1 vulnerabilities

2019-05-02T20:41:27+00:00

commit a7102c7461794a5bb31af24b08e9e0f50038897a upstream.

channel and addr->channel are indirectly controlled by user-space,
hence leading to a potential exploitation of the Spectre variant 1
vulnerability.

These issues were detected with the help of Smatch:

drivers/char/ipmi/ipmi_msghandler.c:1381 ipmi_set_my_address() warn: potential spectre issue 'user->intf->addrinfo' [w] (local cap)
drivers/char/ipmi/ipmi_msghandler.c:1401 ipmi_get_my_address() warn: potential spectre issue 'user->intf->addrinfo' [r] (local cap)
drivers/char/ipmi/ipmi_msghandler.c:1421 ipmi_set_my_LUN() warn: potential spectre issue 'user->intf->addrinfo' [w] (local cap)
drivers/char/ipmi/ipmi_msghandler.c:1441 ipmi_get_my_LUN() warn: potential spectre issue 'user->intf->addrinfo' [r] (local cap)
drivers/char/ipmi/ipmi_msghandler.c:2260 check_addr() warn: potential spectre issue 'intf->addrinfo' [r] (local cap)

Fix this by sanitizing channel and addr->channel before using them to
index user->intf->addrinfo and intf->addrinfo, correspondingly.

Notice that given that speculation windows are large, the policy is
to kill the speculation on the first load and not worry if it can be
completed with a dependent load/store [1].

[1] https://lore.kernel.org/lkml/20180423164740.GY17484@dhcp22.suse.cz/

Signed-off-by: Gustavo A. R. Silva 
Signed-off-by: Corey Minyard 
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings

char/mwave: fix potential Spectre v1 vulnerability

2019-05-02T20:41:26+00:00

commit 701956d4018e5d5438570e39e8bda47edd32c489 upstream.

ipcnum is indirectly controlled by user-space, hence leading to
a potential exploitation of the Spectre variant 1 vulnerability.

This issue was detected with the help of Smatch:

drivers/char/mwave/mwavedd.c:299 mwave_ioctl() warn: potential spectre issue 'pDrvData->IPCs' [w] (local cap)

Fix this by sanitizing ipcnum before using it to index pDrvData->IPCs.

Notice that given that speculation windows are large, the policy is
to kill the speculation on the first load and not worry if it can be
completed with a dependent load/store [1].

[1] https://marc.info/?l=linux-kernel&m=152449131114778&w=2

Signed-off-by: Gustavo A. R. Silva 
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Ben Hutchings

ipmi: Move BT capabilities detection to the detect call

2018-12-16T22:08:57+00:00

commit c86ba91be75702c013bbf7379542920b6920e98f upstream.

The capabilities detection was being done as part of the normal
state machine, but it was possible for it to be running while
the upper layers of the IPMI driver were initializing the
device, resulting in error and failure to initialize.

Move the capabilities detection to the the detect function,
so it's done before anything else runs on the device.  This also
simplifies the state machine and removes some code, as a bonus.

Signed-off-by: Corey Minyard 
Reported-by: Andrew Banman 
Tested-by: Andrew Banman 
[bwh: Backported to 3.16:
 - struct si_sm_data doesn't include a dev pointer, so use pr_* functions
   for logging
 - Include  for schedule_timeout_uninterruptible()]
Signed-off-by: Ben Hutchings

random: mix rdrand with entropy sent in from userspace

2018-11-20T18:05:44+00:00

commit 81e69df38e2911b642ec121dec319fad2a4782f3 upstream.

Fedora has integrated the jitter entropy daemon to work around slow
boot problems, especially on VM's that don't support virtio-rng:

    https://bugzilla.redhat.com/show_bug.cgi?id=1572944

It's understandable why they did this, but the Jitter entropy daemon
works fundamentally on the principle: "the CPU microarchitecture is
**so** complicated and we can't figure it out, so it *must* be
random".  Yes, it uses statistical tests to "prove" it is secure, but
AES_ENCRYPT(NSA_KEY, COUNTER++) will also pass statistical tests with
flying colors.

So if RDRAND is available, mix it into entropy submitted from
userspace.  It can't hurt, and if you believe the NSA has backdoored
RDRAND, then they probably have enough details about the Intel
microarchitecture that they can reverse engineer how the Jitter
entropy daemon affects the microarchitecture, and attack its output
stream.  And if RDRAND is in fact an honest DRNG, it will immeasurably
improve on what the Jitter entropy daemon might produce.

This also provides some protection against someone who is able to read
or set the entropy seed file.

Signed-off-by: Theodore Ts'o 
Cc: Arnd Bergmann 
Signed-off-by: Ben Hutchings

tpm: fix race condition in tpm_common_write()

2018-11-20T18:05:05+00:00

commit 3ab2011ea368ec3433ad49e1b9e1c7b70d2e65df upstream.

There is a race condition in tpm_common_write function allowing
two threads on the same /dev/tpm, or two different applications
on the same /dev/tpmrm to overwrite each other commands/responses.
Fixed this by taking the priv->buffer_mutex early in the function.

Also converted the priv->data_pending from atomic to a regular size_t
type. There is no need for it to be atomic since it is only touched
under the protection of the priv->buffer_mutex.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Tadeusz Struk 
Reviewed-by: Jarkko Sakkinen 
Signed-off-by: Jarkko Sakkinen 
[bwh: Backported to 3.16: adjust filenames, context]
Signed-off-by: Ben Hutchings

ipmi:bt: Set the timeout before doing a capabilities check

2018-11-20T18:05:00+00:00

commit fe50a7d0393a552e4539da2d31261a59d6415950 upstream.

There was one place where the timeout value for an operation was
not being set, if a capabilities request was done from idle.  Move
the timeout value setting to before where that change might be
requested.

IMHO the cause here is the invisible returns in the macros.  Maybe
that's a job for later, though.

Reported-by: Nordmark Claes 
Signed-off-by: Corey Minyard 
Signed-off-by: Ben Hutchings

virtio_console: reset on out of memory

2018-10-21T07:45:45+00:00

commit 5c60300d68da32ca77f7f978039dc72bfc78b06b upstream.

When out of memory and we can't add ctrl vq buffers,
probe fails. Unfortunately the error handling is
out of spec: it calls del_vqs without bothering
to reset the device first.

To fix, call the full cleanup function in this case.

Signed-off-by: Michael S. Tsirkin 
Signed-off-by: Ben Hutchings

virtio_console: move removal code

2018-10-21T07:45:45+00:00

commit aa44ec867030a72e8aa127977e37dec551d8df19 upstream.

Will make it reusable for error handling.

Signed-off-by: Michael S. Tsirkin 
Signed-off-by: Ben Hutchings

virtio_console: drop custom control queue cleanup

2018-10-21T07:45:45+00:00

commit 61a8950c5c5708cf2068b29ffde94e454e528208 upstream.

We now cleanup all VQs on device removal - no need
to handle the control VQ specially.

Signed-off-by: Michael S. Tsirkin 
Signed-off-by: Ben Hutchings