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Hugo Lefeuvre
10db0e22fb
[ Upstream commit 6de4ef65a8 ]
In the PI433_IOC_WR_TX_CFG case in pi433_ioctl, instance->tx_cfg is
modified via
copy_from_user(&instance->tx_cfg, argp, sizeof(struct pi433_tx_cfg)))
without any kind of synchronization. In the case where two threads
would execute this same command concurrently the tx_cfg field might
enter in an inconsistent state.
Additionally: if ioctl(PI433_IOC_WR_TX_CFG) and write() execute
concurrently the tx config might be modified while it is being
copied to the fifo, resulting in potential data corruption.
Fix: Get instance->tx_cfg_lock before modifying tx config in the
PI433_IOC_WR_TX_CFG case in pi433_ioctl.
Also, do not copy data directly from user space to instance->tx_cfg.
Instead use a temporary buffer allowing future checks for correctness
of copied data and simpler code.
Signed-off-by: Hugo Lefeuvre <hle@owl.eu.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>