linux-stable.git/drivers/char, branch v4.19.78

ipmi_si: Only schedule continuously in the thread in maintenance mode

2019-10-07T16:56:39+00:00

[ Upstream commit 340ff31ab00bca5c15915e70ad9ada3030c98cf8 ]

ipmi_thread() uses back-to-back schedule() to poll for command
completion which, on some machines, can push up CPU consumption and
heavily tax the scheduler locks leading to noticeable overall
performance degradation.

This was originally added so firmware updates through IPMI would
complete in a timely manner.  But we can't kill the scheduler
locks for that one use case.

Instead, only run schedule() continuously in maintenance mode,
where firmware updates should run.

Signed-off-by: Corey Minyard 
Signed-off-by: Sasha Levin

tpm: Fix TPM 1.2 Shutdown sequence to prevent future TPM operations

2019-10-07T16:56:28+00:00

commit db4d8cb9c9f2af71c4d087817160d866ed572cc9 upstream

TPM 2.0 Shutdown involve sending TPM2_Shutdown to TPM chip and disabling
future TPM operations. TPM 1.2 behavior was different, future TPM
operations weren't disabled, causing rare issues. This patch ensures
that future TPM operations are disabled.

Fixes: d1bd4a792d39 ("tpm: Issue a TPM2_Shutdown for TPM2 devices.")
Cc: stable@vger.kernel.org
Signed-off-by: Vadim Sukhomlinov 
[dianders: resolved merge conflicts with mainline]
Signed-off-by: Douglas Anderson 
Reviewed-by: Jarkko Sakkinen 
Signed-off-by: Jarkko Sakkinen 
Signed-off-by: Sasha Levin

tpm: use tpm_try_get_ops() in tpm-sysfs.c.

2019-10-07T16:56:27+00:00

commit 2677ca98ae377517930c183248221f69f771c921 upstream

Use tpm_try_get_ops() in tpm-sysfs.c so that we can consider moving
other decorations (locking, localities, power management for example)
inside it. This direction can be of course taken only after other call
sites for tpm_transmit() have been treated in the same way.

Signed-off-by: Jarkko Sakkinen 
Reviewed-by: Stefan Berger 
Tested-by: Stefan Berger 
Reviewed-by: Jerry Snitselaar 
Reviewed-by: James Bottomley 
Tested-by: Alexander Steffen 
Signed-off-by: Sasha Levin

hwrng: core - don't wait on add_early_randomness()

2019-10-05T11:10:12+00:00

commit 78887832e76541f77169a24ac238fccb51059b63 upstream.

add_early_randomness() is called by hwrng_register() when the
hardware is added. If this hardware and its module are present
at boot, and if there is no data available the boot hangs until
data are available and can't be interrupted.

For instance, in the case of virtio-rng, in some cases the host can be
not able to provide enough entropy for all the guests.

We can have two easy ways to reproduce the problem but they rely on
misconfiguration of the hypervisor or the egd daemon:

- if virtio-rng device is configured to connect to the egd daemon of the
host but when the virtio-rng driver asks for data the daemon is not
connected,

- if virtio-rng device is configured to connect to the egd daemon of the
host but the egd daemon doesn't provide data.

The guest kernel will hang at boot until the virtio-rng driver provides
enough data.

To avoid that, call rng_get_data() in non-blocking mode (wait=0)
from add_early_randomness().

Signed-off-by: Laurent Vivier 
Fixes: d9e797261933 ("hwrng: add randomness to system from rng...")
Cc: 
Reviewed-by: Theodore Ts'o 
Signed-off-by: Herbert Xu 
Signed-off-by: Greg Kroah-Hartman

/dev/mem: Bail out upon SIGKILL.

2019-10-05T11:10:11+00:00

commit 8619e5bdeee8b2c685d686281f2d2a6017c4bc15 upstream.

syzbot found that a thread can stall for minutes inside read_mem() or
write_mem() after that thread was killed by SIGKILL [1]. Reading from
iomem areas of /dev/mem can be slow, depending on the hardware.
While reading 2GB at one read() is legal, delaying termination of killed
thread for minutes is bad. Thus, allow reading/writing /dev/mem and
/dev/kmem to be preemptible and killable.

  [ 1335.912419][T20577] read_mem: sz=4096 count=2134565632
  [ 1335.943194][T20577] read_mem: sz=4096 count=2134561536
  [ 1335.978280][T20577] read_mem: sz=4096 count=2134557440
  [ 1336.011147][T20577] read_mem: sz=4096 count=2134553344
  [ 1336.041897][T20577] read_mem: sz=4096 count=2134549248

Theoretically, reading/writing /dev/mem and /dev/kmem can become
"interruptible". But this patch chose "killable". Future patch will make
them "interruptible" so that we can revert to "killable" if some program
regressed.

[1] https://syzkaller.appspot.com/bug?id=a0e3436829698d5824231251fad9d8e998f94f5e

Signed-off-by: Tetsuo Handa 
Cc: stable 
Reported-by: syzbot 
Link: https://lore.kernel.org/r/1566825205-10703-1-git-send-email-penguin-kernel@I-love.SAKURA.ne.jp
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Greg Kroah-Hartman

tpm: Fix some name collisions with drivers/char/tpm.h

2019-09-16T06:22:05+00:00

[ Upstream commit 8ab547a2dcfac6ec184a5e036e1093eb3f7a215c ]

* Rename TPM_BUFSIZE defined in drivers/char/tpm/st33zp24/st33zp24.h to
  ST33ZP24_BUFSIZE.
* Rename TPM_BUFSIZE defined in drivers/char/tpm/tpm_i2c_infineon.c to
  TPM_I2C_INFINEON_BUFSIZE.
* Rename TPM_RETRY in tpm_i2c_nuvoton to TPM_I2C_RETRIES.
* Remove TPM_HEADER_SIZE from tpm_i2c_nuvoton.

Cc: stable@vger.kernel.org
Fixes: bf38b8710892 ("tpm/tpm_i2c_stm_st33: Split tpm_i2c_tpm_st33 in 2 layers (core + phy)")
Fixes: aad628c1d91a ("char/tpm: Add new driver for Infineon I2C TIS TPM")
Fixes: 32d33b29ba07 ("TPM: Retry SaveState command in suspend path")
Signed-off-by: Jarkko Sakkinen 
Signed-off-by: Sasha Levin

hpet: Fix division by zero in hpet_time_div()

2019-07-31T05:27:10+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

2019-05-31T13:46:31+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

2019-05-31T13:46:29+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

2019-05-31T13:46:19+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