linux-stable.git/drivers/char, branch v4.14.136

hpet: Fix division by zero in hpet_time_div()

2019-07-31T05:28:58+00:00

commit 0c7d37f4d9b8446956e97b7c5e61173cdb7c8522 upstream.

The base value in do_div() called by hpet_time_div() is truncated from
unsigned long to uint32_t, resulting in a divide-by-zero exception.

UBSAN: Undefined behaviour in ../drivers/char/hpet.c:572:2
division by zero
CPU: 1 PID: 23682 Comm: syz-executor.3 Not tainted 4.4.184.x86_64+ #4
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014
 0000000000000000 b573382df1853d00 ffff8800a3287b98 ffffffff81ad7561
 ffff8800a3287c00 ffffffff838b35b0 ffffffff838b3860 ffff8800a3287c20
 0000000000000000 ffff8800a3287bb0 ffffffff81b8f25e ffffffff838b35a0
Call Trace:
 [] __dump_stack lib/dump_stack.c:15 [inline]
 [] dump_stack+0xc1/0x120 lib/dump_stack.c:51
 [] ubsan_epilogue+0x12/0x8d lib/ubsan.c:166
 [] __ubsan_handle_divrem_overflow+0x282/0x2c8 lib/ubsan.c:262
 [] hpet_time_div drivers/char/hpet.c:572 [inline]
 [] hpet_ioctl_common drivers/char/hpet.c:663 [inline]
 [] hpet_ioctl_common.cold+0xa8/0xad drivers/char/hpet.c:577
 [] hpet_ioctl+0xc6/0x180 drivers/char/hpet.c:676
 [] vfs_ioctl fs/ioctl.c:43 [inline]
 [] file_ioctl fs/ioctl.c:470 [inline]
 [] do_vfs_ioctl+0x6e0/0xf70 fs/ioctl.c:605
 [] SYSC_ioctl fs/ioctl.c:622 [inline]
 [] SyS_ioctl+0x94/0xc0 fs/ioctl.c:613
 [] tracesys_phase2+0x90/0x95

The main C reproducer autogenerated by syzkaller,

  syscall(__NR_mmap, 0x20000000, 0x1000000, 3, 0x32, -1, 0);
  memcpy((void*)0x20000100, "/dev/hpet\000", 10);
  syscall(__NR_openat, 0xffffffffffffff9c, 0x20000100, 0, 0);
  syscall(__NR_ioctl, r[0], 0x40086806, 0x40000000000000);

Fix it by using div64_ul().

Signed-off-by: Kefeng Wang 
Signed-off-by: Zhang HongJun 
Cc: stable 
Reviewed-by: Arnd Bergmann 
Link: https://lore.kernel.org/r/20190711132757.130092-1-wangkefeng.wang@huawei.com
Signed-off-by: Greg Kroah-Hartman

hwrng: omap - Set default quality

2019-05-31T13:47:34+00:00

[ Upstream commit 62f95ae805fa9e1e84d47d3219adddd97b2654b7 ]

Newer combinations of the glibc, kernel and openssh can result in long initial
startup times on OMAP devices:

[    6.671425] systemd-rc-once[102]: Creating ED25519 key; this may take some time ...
[  142.652491] systemd-rc-once[102]: Creating ED25519 key; done.

due to the blocking getrandom(2) system call:

[  142.610335] random: crng init done

Set the quality level for the omap hwrng driver allowing the kernel to use the
hwrng as an entropy source at boot.

Signed-off-by: Rouven Czerwinski 
Signed-off-by: Herbert Xu 
Signed-off-by: Sasha Levin

virtio_console: initialize vtermno value for ports

2019-05-31T13:47:32+00:00

[ Upstream commit 4b0a2c5ff7215206ea6135a405f17c5f6fca7d00 ]

For regular serial ports we do not initialize value of vtermno
variable. A garbage value is assigned for non console ports.
The value can be observed as a random integer with [1].

[1] vim /sys/kernel/debug/virtio-ports/vport*p*

This patch initialize the value of vtermno for console serial
ports to '1' and regular serial ports are initiaized to '0'.

Reported-by: siliu@redhat.com
Signed-off-by: Pankaj Gupta 
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Sasha Levin

random: add a spinlock_t to struct batched_entropy

2019-05-31T13:47:25+00:00

[ Upstream commit b7d5dc21072cda7124d13eae2aefb7343ef94197 ]

The per-CPU variable batched_entropy_uXX is protected by get_cpu_var().
This is just a preempt_disable() which ensures that the variable is only
from the local CPU. It does not protect against users on the same CPU
from another context. It is possible that a preemptible context reads
slot 0 and then an interrupt occurs and the same value is read again.

The above scenario is confirmed by lockdep if we add a spinlock:
| ================================
| WARNING: inconsistent lock state
| 5.1.0-rc3+ #42 Not tainted
| --------------------------------
| inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage.
| ksoftirqd/9/56 [HC0[0]:SC1[1]:HE0:SE0] takes:
| (____ptrval____) (batched_entropy_u32.lock){+.?.}, at: get_random_u32+0x3e/0xe0
| {SOFTIRQ-ON-W} state was registered at:
|   _raw_spin_lock+0x2a/0x40
|   get_random_u32+0x3e/0xe0
|   new_slab+0x15c/0x7b0
|   ___slab_alloc+0x492/0x620
|   __slab_alloc.isra.73+0x53/0xa0
|   kmem_cache_alloc_node+0xaf/0x2a0
|   copy_process.part.41+0x1e1/0x2370
|   _do_fork+0xdb/0x6d0
|   kernel_thread+0x20/0x30
|   kthreadd+0x1ba/0x220
|   ret_from_fork+0x3a/0x50
…
| other info that might help us debug this:
|  Possible unsafe locking scenario:
|
|        CPU0
|        ----
|   lock(batched_entropy_u32.lock);
|   
|     lock(batched_entropy_u32.lock);
|
|  *** DEADLOCK ***
|
| stack backtrace:
| Call Trace:
…
|  kmem_cache_alloc_trace+0x20e/0x270
|  ipmi_alloc_recv_msg+0x16/0x40
…
|  __do_softirq+0xec/0x48d
|  run_ksoftirqd+0x37/0x60
|  smpboot_thread_fn+0x191/0x290
|  kthread+0xfe/0x130
|  ret_from_fork+0x3a/0x50

Add a spinlock_t to the batched_entropy data structure and acquire the
lock while accessing it. Acquire the lock with disabled interrupts
because this function may be used from interrupt context.

Remove the batched_entropy_reset_lock lock. Now that we have a lock for
the data scructure, we can access it from a remote CPU.

Signed-off-by: Sebastian Andrzej Siewior 
Signed-off-by: Theodore Ts'o 
Signed-off-by: Sasha Levin

ipmi:ssif: compare block number correctly for multi-part return messages

2019-05-21T16:50:19+00:00

commit 55be8658c7e2feb11a5b5b33ee031791dbd23a69 upstream.

According to ipmi spec, block number is a number that is incremented,
starting with 0, for each new block of message data returned using the
middle transaction.

Here, the 'blocknum' is data[0] which always starts from zero(0) and
'ssif_info->multi_pos' starts from 1.
So, we need to add +1 to blocknum while comparing with multi_pos.

Fixes: 7d6380cd40f79 ("ipmi:ssif: Fix handling of multi-part return messages").
Reported-by: Kiran Kolukuluru 
Signed-off-by: Kamlakant Patel 
Message-Id: <1556106615-18722-1-git-send-email-kamlakantp@marvell.com>
[Also added a debug log if the block numbers don't match.]
Signed-off-by: Corey Minyard 
Cc: stable@vger.kernel.org # 4.4
Signed-off-by: Greg Kroah-Hartman

tpm/tpm_i2c_atmel: Return -E2BIG when the transfer is incomplete

2019-04-27T07:35:40+00:00

[ Upstream commit 442601e87a4769a8daba4976ec3afa5222ca211d ]

Return -E2BIG when the transfer is incomplete. The upper layer does
not retry, so not doing that is incorrect behaviour.

Cc: stable@vger.kernel.org
Fixes: a2871c62e186 ("tpm: Add support for Atmel I2C TPMs")
Signed-off-by: Jarkko Sakkinen 
Reviewed-by: Stefan Berger 
Reviewed-by: Jerry Snitselaar 
Signed-off-by: Sasha Levin

tty: mark Siemens R3964 line discipline as BROKEN

2019-04-17T06:37:44+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

hpet: Fix missing '=' character in the __setup() code of hpet_mmap_enable

2019-04-05T20:31:38+00:00

[ Upstream commit 24d48a61f2666630da130cc2ec2e526eacf229e3 ]

Commit '3d035f580699 ("drivers/char/hpet.c: allow user controlled mmap for
user processes")' introduced a new kernel command line parameter hpet_mmap,
that is required to expose the memory map of the HPET registers to
user-space. Unfortunately the kernel command line parameter 'hpet_mmap' is
broken and never takes effect due to missing '=' character in the __setup()
code of hpet_mmap_enable.

Before this patch:

dmesg output with the kernel command line parameter hpet_mmap=1

[    0.204152] HPET mmap disabled

dmesg output with the kernel command line parameter hpet_mmap=0

[    0.204192] HPET mmap disabled

After this patch:

dmesg output with the kernel command line parameter hpet_mmap=1

[    0.203945] HPET mmap enabled

dmesg output with the kernel command line parameter hpet_mmap=0

[    0.204652] HPET mmap disabled

Fixes: 3d035f580699 ("drivers/char/hpet.c: allow user controlled mmap for user processes")
Signed-off-by: Buland Singh 
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Sasha Levin

hwrng: virtio - Avoid repeated init of completion

2019-04-05T20:31:38+00:00

[ Upstream commit aef027db48da56b6f25d0e54c07c8401ada6ce21 ]

The virtio-rng driver uses a completion called have_data to wait for a
virtio read to be fulfilled by the hypervisor. The completion is reset
before placing a buffer on the virtio queue and completed by the virtio
callback once data has been written into the buffer.

Prior to this commit, the driver called init_completion on this
completion both during probe as well as when registering virtio buffers
as part of a hwrng read operation. The second of these init_completion
calls should instead be reinit_completion because the have_data
completion has already been inited by probe. As described in
Documentation/scheduler/completion.txt, "Calling init_completion() twice
on the same completion object is most likely a bug".

This bug was present in the initial implementation of virtio-rng in
f7f510ec1957 ("virtio: An entropy device, as suggested by hpa"). Back
then the have_data completion was a single static completion rather than
a member of one of potentially multiple virtrng_info structs as
implemented later by 08e53fbdb85c ("virtio-rng: support multiple
virtio-rng devices"). The original driver incorrectly used
init_completion rather than INIT_COMPLETION to reset have_data during
read.

Tested by running `head -c48 /dev/random | hexdump` within crosvm, the
Chrome OS virtual machine monitor, and confirming that the virtio-rng
driver successfully produces random bytes from the host.

Signed-off-by: David Tolnay 
Tested-by: David Tolnay 
Signed-off-by: Herbert Xu 
Signed-off-by: Sasha Levin

tpm: Unify the send callback behaviour

2019-03-23T13:35:30+00:00

commit f5595f5baa30e009bf54d0d7653a9a0cc465be60 upstream.

The send() callback should never return length as it does not in every
driver except tpm_crb in the success case. The reason is that the main
transmit functionality only cares about whether the transmit was
successful or not and ignores the count completely.

Suggested-by: Stefan Berger 
Cc: stable@vger.kernel.org
Signed-off-by: Jarkko Sakkinen 
Reviewed-by: Stefan Berger 
Reviewed-by: Jerry Snitselaar 
Tested-by: Alexander Steffen 
Signed-off-by: Greg Kroah-Hartman