From 89efbe70b27dd325d8a8c177743a26b885f7faec Mon Sep 17 00:00:00 2001
From: Lukas Wunner <lukas@wunner.de>
Date: Thu, 13 Aug 2020 12:59:54 +0200
Subject: [PATCH] serial: pl011: Don't leak amba_ports entry on driver register error
Git-commit: 89efbe70b27dd325d8a8c177743a26b885f7faec
Patch-mainline: v5.9-rc3
References: git-fixes
pl011_probe() calls pl011_setup_port() to reserve an amba_ports[] entry,
then calls pl011_register_port() to register the uart driver with the
tty layer.
If registration of the uart driver fails, the amba_ports[] entry is not
released. If this happens 14 times (value of UART_NR macro), then all
amba_ports[] entries will have been leaked and driver probing is no
longer possible. (To be fair, that can only happen if the DeviceTree
doesn't contain alias IDs since they cause the same entry to be used for
a given port.) Fix it.
Fixes: ef2889f7ffee ("serial: pl011: Move uart_register_driver call to device")
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Cc: stable@vger.kernel.org # v3.15+
Cc: Tushar Behera <tushar.behera@linaro.org>
Link: https://lore.kernel.org/r/138f8c15afb2f184d8102583f8301575566064a6.1597316167.git.lukas@wunner.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Takashi Iwai <tiwai@suse.de>
---
drivers/tty/serial/amba-pl011.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c
index c010f639298d..7893048bea2d 100644
--- a/drivers/tty/serial/amba-pl011.c
+++ b/drivers/tty/serial/amba-pl011.c
@@ -2615,7 +2615,7 @@ static int pl011_setup_port(struct device *dev, struct uart_amba_port *uap,
static int pl011_register_port(struct uart_amba_port *uap)
{
- int ret;
+ int ret, i;
/* Ensure interrupts from this UART are masked and cleared */
pl011_write(0, uap, REG_IMSC);
@@ -2626,6 +2626,9 @@ static int pl011_register_port(struct uart_amba_port *uap)
if (ret < 0) {
dev_err(uap->port.dev,
"Failed to register AMBA-PL011 driver\n");
+ for (i = 0; i < ARRAY_SIZE(amba_ports); i++)
+ if (amba_ports[i] == uap)
+ amba_ports[i] = NULL;
return ret;
}
}
--
2.16.4