linux-stable.git/drivers/char, branch v5.4.252

hwrng: imx-rngc - fix the timeout for init and self check

2023-07-27T06:37:38+00:00

commit d744ae7477190967a3ddc289e2cd4ae59e8b1237 upstream.

Fix the timeout that is used for the initialisation and for the self
test. wait_for_completion_timeout expects a timeout in jiffies, but
RNGC_TIMEOUT is in milliseconds. Call msecs_to_jiffies to do the
conversion.

Cc: stable@vger.kernel.org
Fixes: 1d5449445bd0 ("hwrng: mx-rngc - add a driver for Freescale RNGC")
Signed-off-by: Martin Kaiser 
Signed-off-by: Herbert Xu 
Signed-off-by: Greg Kroah-Hartman

tpm: tpm_vtpm_proxy: fix a race condition in /dev/vtpmx creation

2023-07-27T06:37:34+00:00

commit f4032d615f90970d6c3ac1d9c0bce3351eb4445c upstream.

/dev/vtpmx is made visible before 'workqueue' is initialized, which can
lead to a memory corruption in the worst case scenario.

Address this by initializing 'workqueue' as the very first step of the
driver initialization.

Cc: stable@vger.kernel.org
Fixes: 6f99612e2500 ("tpm: Proxy driver for supporting multiple emulated TPMs")
Reviewed-by: Stefan Berger 
Signed-off-by: Jarkko Sakkinen 
Signed-off-by: Jarkko Sakkinen 
Signed-off-by: Greg Kroah-Hartman

hwrng: st - keep clock enabled while hwrng is registered

2023-07-27T06:37:19+00:00

[ Upstream commit 501e197a02d4aef157f53ba3a0b9049c3e52fedc ]

The st-rng driver uses devres to register itself with the hwrng core,
the driver will be unregistered from hwrng when its device goes out of
scope. This happens after the driver's remove function is called.

However, st-rng's clock is disabled in the remove function. There's a
short timeframe where st-rng is still registered with the hwrng core
although its clock is disabled. I suppose the clock must be active to
access the hardware and serve requests from the hwrng core.

Switch to devm_clk_get_enabled and let devres disable the clock and
unregister the hwrng. This avoids the race condition.

Fixes: 3e75241be808 ("hwrng: drivers - Use device-managed registration API")
Signed-off-by: Martin Kaiser 
Signed-off-by: Herbert Xu 
Signed-off-by: Sasha Levin

hwrng: st - Fix W=1 unused variable warning

2023-07-27T06:37:19+00:00

[ Upstream commit ad23756271d5744a0a0ba556f8aaa70e358d5aa6 ]

This patch fixes an unused variable warning when this driver is
built-in with CONFIG_OF=n.

Signed-off-by: Herbert Xu 
Stable-dep-of: 501e197a02d4 ("hwrng: st - keep clock enabled while hwrng is registered")
Signed-off-by: Sasha Levin

hwrng: virtio - Fix race on data_avail and actual data

2023-07-27T06:37:18+00:00

[ Upstream commit ac52578d6e8d300dd50f790f29a24169b1edd26c ]

The virtio rng device kicks off a new entropy request whenever the
data available reaches zero.  When a new request occurs at the end
of a read operation, that is, when the result of that request is
only needed by the next reader, then there is a race between the
writing of the new data and the next reader.

This is because there is no synchronisation whatsoever between the
writer and the reader.

Fix this by writing data_avail with smp_store_release and reading
it with smp_load_acquire when we first enter read.  The subsequent
reads are safe because they're either protected by the first load
acquire, or by the completion mechanism.

Also remove the redundant zeroing of data_idx in random_recv_done
(data_idx must already be zero at this point) and data_avail in
request_entropy (ditto).

Reported-by: syzbot+726dc8c62c3536431ceb@syzkaller.appspotmail.com
Fixes: f7f510ec1957 ("virtio: An entropy device, as suggested by hpa.")
Signed-off-by: Herbert Xu 
Acked-by: Michael S. Tsirkin 
Signed-off-by: Herbert Xu 
Signed-off-by: Sasha Levin

hwrng: virtio - always add a pending request

2023-07-27T06:37:17+00:00

[ Upstream commit 9a4b612d675b03f7fc9fa1957ca399c8223f3954 ]

If we ensure we have already some data available by enqueuing
again the buffer once data are exhausted, we can return what we
have without waiting for the device answer.

Signed-off-by: Laurent Vivier 
Link: https://lore.kernel.org/r/20211028101111.128049-5-lvivier@redhat.com
Signed-off-by: Michael S. Tsirkin 
Stable-dep-of: ac52578d6e8d ("hwrng: virtio - Fix race on data_avail and actual data")
Signed-off-by: Sasha Levin

hwrng: virtio - don't waste entropy

2023-07-27T06:37:17+00:00

[ Upstream commit 5c8e933050044d6dd2a000f9a5756ae73cbe7c44 ]

if we don't use all the entropy available in the buffer, keep it
and use it later.

Signed-off-by: Laurent Vivier 
Link: https://lore.kernel.org/r/20211028101111.128049-4-lvivier@redhat.com
Signed-off-by: Michael S. Tsirkin 
Stable-dep-of: ac52578d6e8d ("hwrng: virtio - Fix race on data_avail and actual data")
Signed-off-by: Sasha Levin

hwrng: virtio - don't wait on cleanup

2023-07-27T06:37:17+00:00

[ Upstream commit 2bb31abdbe55742c89f4dc0cc26fcbc8467364f6 ]

When virtio-rng device was dropped by the hwrng core we were forced
to wait the buffer to come back from the device to not have
remaining ongoing operation that could spoil the buffer.

But now, as the buffer is internal to the virtio-rng we can release
the waiting loop immediately, the buffer will be retrieve and use
when the virtio-rng driver will be selected again.

This avoids to hang on an rng_current write command if the virtio-rng
device is blocked by a lack of entropy. This allows to select
another entropy source if the current one is empty.

Signed-off-by: Laurent Vivier 
Link: https://lore.kernel.org/r/20211028101111.128049-3-lvivier@redhat.com
Signed-off-by: Michael S. Tsirkin 
Stable-dep-of: ac52578d6e8d ("hwrng: virtio - Fix race on data_avail and actual data")
Signed-off-by: Sasha Levin

hwrng: virtio - add an internal buffer

2023-07-27T06:37:17+00:00

[ Upstream commit bf3175bc50a3754dc427e2f5046e17a9fafc8be7 ]

hwrng core uses two buffers that can be mixed in the
virtio-rng queue.

If the buffer is provided with wait=0 it is enqueued in the
virtio-rng queue but unused by the caller.
On the next call, core provides another buffer but the
first one is filled instead and the new one queued.
And the caller reads the data from the new one that is not
updated, and the data in the first one are lost.

To avoid this mix, virtio-rng needs to use its own unique
internal buffer at a cost of a data copy to the caller buffer.

Signed-off-by: Laurent Vivier 
Link: https://lore.kernel.org/r/20211028101111.128049-2-lvivier@redhat.com
Signed-off-by: Michael S. Tsirkin 
Stable-dep-of: ac52578d6e8d ("hwrng: virtio - Fix race on data_avail and actual data")
Signed-off-by: Sasha Levin

parisc: Flush gatt writes and adjust gatt mask in parisc_agp_mask_memory()

2023-06-21T13:44:09+00:00

[ Upstream commit d703797380c540bbeac03f104ebcfc364eaf47cc ]

Flush caches after changing gatt entries and calculate entry according
to SBA requirements.

Signed-off-by: Helge Deller 
Signed-off-by: Sasha Levin