kernel/linux.git/drivers/char/hw_random, branch v6.1.87

hwrng: core - Fix page fault dead lock on mmap-ed hwrng

2024-02-01T00:16:58+00:00

commit 78aafb3884f6bc6636efcc1760c891c8500b9922 upstream. There is a dead-lock in the hwrng device read path. This triggers when the user reads from /dev/hwrng into memory also mmap-ed from /dev/hwrng. The resulting page fault triggers a recursive read which then dead-locks. Fix this by using a stack buffer when calling copy_to_user. Reported-by: Edward Adam Davis Reported-by: syzbot+c52ab18308964d248092@syzkaller.appspotmail.com Fixes: 9996508b3353 ("hwrng: core - Replace u32 in driver API with byte array") Cc: Signed-off-by: Herbert Xu Signed-off-by: Greg Kroah-Hartman

hwrng: geode - fix accessing registers

2023-11-20T10:52:04+00:00

[ Upstream commit 464bd8ec2f06707f3773676a1bd2c64832a3c805 ] When the membase and pci_dev pointer were moved to a new struct in priv, the actual membase users were left untouched, and they started reading out arbitrary memory behind the struct instead of registers. This unfortunately turned the RNG into a constant number generator, depending on the content of what was at that offset. To fix this, update geode_rng_data_{read,present}() to also get the membase via amd_geode_priv, and properly read from the right addresses again. Fixes: 9f6ec8dc574e ("hwrng: geode - Fix PCI device refcount leak") Reported-by: Timur I. Davletshin Closes: https://bugzilla.kernel.org/show_bug.cgi?id=217882 Tested-by: Timur I. Davletshin Suggested-by: Jo-Philipp Wich Signed-off-by: Jonas Gorski Signed-off-by: Herbert Xu Signed-off-by: Sasha Levin

hwrng: bcm2835 - Fix hwrng throughput regression

2023-11-20T10:52:04+00:00

[ Upstream commit b58a36008bfa1aadf55f516bcbfae40c779eb54b ] The last RCU stall fix caused a massive throughput regression of the hwrng on Raspberry Pi 0 - 3. hwrng_msleep doesn't sleep precisely enough and usleep_range doesn't allow scheduling. So try to restore the best possible throughput by introducing hwrng_yield which interruptable sleeps for one jiffy. Some performance measurements on Raspberry Pi 3B+ (arm64/defconfig): sudo dd if=/dev/hwrng of=/dev/null count=1 bs=10000 cpu_relax ~138025 Bytes / sec hwrng_msleep(1000) ~13 Bytes / sec hwrng_yield ~2510 Bytes / sec Fixes: 96cb9d055445 ("hwrng: bcm2835 - use hwrng_msleep() instead of cpu_relax()") Link: https://lore.kernel.org/linux-arm-kernel/bc97ece5-44a3-4c4e-77da-2db3eb66b128@gmx.net/ Signed-off-by: Stefan Wahren Reviewed-by: Jason A. Donenfeld Signed-off-by: Herbert Xu Signed-off-by: Sasha Levin

hwrng: iproc-rng200 - Implement suspend and resume calls

2023-09-13T07:42:33+00:00

[ Upstream commit 8e03dd62e5be811efbf0cbeba47e79e793519105 ] Chips such as BCM7278 support system wide suspend/resume which will cause the HWRNG block to lose its state and reset to its power on reset register values. We need to cleanup and re-initialize the HWRNG for it to be functional coming out of a system suspend cycle. Fixes: c3577f6100ca ("hwrng: iproc-rng200 - Add support for BCM7278") Signed-off-by: Florian Fainelli Signed-off-by: Herbert Xu Signed-off-by: Sasha Levin

hwrng: pic32 - use devm_clk_get_enabled

2023-09-13T07:42:31+00:00

[ Upstream commit 6755ad74aac0fb1c79b14724feb81b2f6ff25847 ] Use devm_clk_get_enabled in the pic32 driver. Ensure that the clock is enabled as long as the driver is registered with the hwrng core. Fixes: 7ea39973d1e5 ("hwrng: pic32 - Use device-managed registration API") Signed-off-by: Martin Kaiser Signed-off-by: Herbert Xu Signed-off-by: Sasha Levin

hwrng: nomadik - keep clock enabled while hwrng is registered

2023-09-13T07:42:30+00:00

[ Upstream commit 039980de89dc9dd757418d6f296e4126cc3f86c3 ] The nomadik 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, nomadik's clock is disabled in the remove function. There's a short timeframe where nomadik 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: imx-rngc - fix the timeout for init and self check

2023-07-23T11:49:35+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

hwrng: st - keep clock enabled while hwrng is registered

2023-07-19T14:21:44+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: virtio - Fix race on data_avail and actual data

2023-07-19T14:21:41+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: geode - Fix PCI device refcount leak

2022-12-31T12:32:37+00:00

[ Upstream commit 9f6ec8dc574efb7f4f3d7ee9cd59ae307e78f445 ] for_each_pci_dev() is implemented by pci_get_device(). The comment of pci_get_device() says that it will increase the reference count for the returned pci_dev and also decrease the reference count for the input pci_dev @from if it is not NULL. If we break for_each_pci_dev() loop with pdev not NULL, we need to call pci_dev_put() to decrease the reference count. We add a new struct 'amd_geode_priv' to record pointer of the pci_dev and membase, and then add missing pci_dev_put() for the normal and error path. Fixes: ef5d862734b8 ("[PATCH] Add Geode HW RNG driver") Signed-off-by: Xiongfeng Wang Signed-off-by: Herbert Xu Signed-off-by: Sasha Levin