Ilpo Järvinen 9d25aea2ab serial: 8250_dma: Fix DMA Rx rearm race ... commit 57e9af7831 upstream. As DMA Rx can be completed from two places, it is possible that DMA Rx completes before DMA completion callback had a chance to complete it. Once the previous DMA Rx has been completed, a new one can be started on the next UART interrupt. The following race is possible (uart_unlock_and_check_sysrq_irqrestore() replaced with spin_unlock_irqrestore() for simplicity/clarity): CPU0 CPU1 dma_rx_complete() serial8250_handle_irq() spin_lock_irqsave(&port->lock) handle_rx_dma() serial8250_rx_dma_flush() __dma_rx_complete() dma->rx_running = 0 // Complete DMA Rx spin_unlock_irqrestore(&port->lock) serial8250_handle_irq() spin_lock_irqsave(&port->lock) handle_rx_dma() serial8250_rx_dma() dma->rx_running = 1 // Setup a new DMA Rx spin_unlock_irqrestore(&port->lock) spin_lock_irqsave(&port->lock) // sees dma->rx_running = 1 __dma_rx_complete() dma->rx_running = 0 // Incorrectly complete // running DMA Rx This race seems somewhat theoretical to occur for real but handle it correctly regardless. Check what is the DMA status before complething anything in __dma_rx_complete(). Reported-by: Gilles BULOZ <gilles.buloz@kontron.com> Tested-by: Gilles BULOZ <gilles.buloz@kontron.com> Fixes: 9ee4b83e51 ("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/20230130114841.25749-3-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>		2023-02-09 11:28:25 +01:00
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hvc	hvc/xen: lock console list traversal	2023-01-18 11:58:26 +01:00
ipwireless	…
serdev	…
serial	serial: 8250_dma: Fix DMA Rx rearm race	2023-02-09 11:28:25 +01:00
vt	vc_screen: move load of struct vc_data pointer in vcs_read() to avoid UAF	2023-02-09 11:28:14 +01:00
Kconfig	…
Makefile	…
amiserial.c	…
ehv_bytechan.c	…
goldfish.c	…
mips_ejtag_fdc.c	…
moxa.c	…
mxser.c	tty: mxser: remove redundant assignment to hwid	2022-09-01 17:59:36 +02:00
n_gsm.c	tty: n_gsm: fix sleep-in-atomic-context bug in gsm_control_send	2022-11-03 04:12:09 +01:00
n_hdlc.c	tty: n_hdlc: remove HDLC_MAGIC	2022-09-22 16:12:34 +02:00
n_null.c	…
n_tty.c	…
nozomi.c	…
pty.c	…
rpmsg_tty.c	…
synclink_gt.c	tty: synclink_gt: remove MGSL_MAGIC	2022-09-22 16:12:34 +02:00
sysrq.c	…
tty.h	…
tty_audit.c	…
tty_baudrate.c	…
tty_buffer.c	…
tty_io.c	tty: remove TTY_DRIVER_MAGIC	2022-09-22 16:12:34 +02:00
tty_ioctl.c	termios: start unifying non-UAPI parts of asm/termios.h	2022-09-09 10:44:34 +02:00
tty_jobctrl.c	…
tty_ldisc.c	…
tty_ldsem.c	…
tty_mutex.c	tty: remove TTY_MAGIC	2022-09-22 16:12:34 +02:00
tty_port.c	…
ttynull.c	…
vcc.c	termios: start unifying non-UAPI parts of asm/termios.h	2022-09-09 10:44:34 +02:00