sci_request_irq() checks port->irqstr[j] for a NULL pointer, to decide
if a fallback interrupt name string should be allocated or not.
While this string is freed during port shutdown, the pointer is not
zeroed. Hence on a subsequent startup of the port, it will still be
pointing to the freed memory, leading to e.g.
WARNING: CPU: 0 PID: 404 at fs/proc/generic.c:388 __proc_create+0xbc/0x260
name len 0
or to a crash (the latter is more likely with CONFIG_DEBUG_SLAB=y, due
to the poisoning of freed memory).
Instead of zeroeing the pointer at multiple places, preinitialize
port->irqstr[j] to zero to fix this.
Fixes: 8b0bbd956228ae87 ("serial: sh-sci: Add support for R7S9210")
Signed-off-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
---
drivers/tty/serial/sh-sci.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c
index 5808edfe3f7be404..f8e53ac5c17dfb94 100644
--- a/drivers/tty/serial/sh-sci.c
+++ b/drivers/tty/serial/sh-sci.c
@@ -1872,6 +1872,7 @@ static int sci_request_irq(struct sci_port *port)
}
desc = sci_irq_desc + i;
+ port->irqstr[j] = NULL;
if (SCIx_TEIDRI_IRQ_EXISTS(port)) {
/*
* ERI and BRI are muxed, just register ERI and
--
2.17.1
