On Tue, Feb 07, 2023 at 11:47:16AM +0200, Ilpo Järvinen wrote:
[ Upstream commit 31352811e13dc2313f101b890fd4b1ce760b5fe7 ]
__dma_rx_complete() is called from two places:
- Through the DMA completion callback dma_rx_complete()
- From serial8250_rx_dma_flush() after IIR_RLSI or IIR_RX_TIMEOUT
The former does not hold port's lock during __dma_rx_complete() which allows these two to race and potentially insert the same data twice.
Extend port's lock coverage in dma_rx_complete() to prevent the race and check if the DMA Rx is still pending completion before calling into __dma_rx_complete().
Reported-by: Gilles BULOZ gilles.buloz@kontron.com Tested-by: Gilles BULOZ gilles.buloz@kontron.com Fixes: 9ee4b83e51f7 ("serial: 8250: Add support for dmaengine") Cc: stable@vger.kernel.org Signed-off-by: Ilpo Järvinen ilpo.jarvinen@linux.intel.com Link: https://lore.kernel.org/r/20230130114841.25749-2-ilpo.jarvinen@linux.intel.c... Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
drivers/tty/serial/8250/8250_dma.c | 14 +++++++++++++- 1 file changed, 13 insertions(+), 1 deletion(-)
Thanks, both queued up now.
greg k-h