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Message-Id: <20220418121202.549234868@linuxfoundation.org>
Date: Mon, 18 Apr 2022 14:12:49 +0200
From: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To: linux-kernel@...r.kernel.org
Cc: Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
stable@...r.kernel.org, Jiri Slaby <jslaby@...e.cz>,
Sasha Levin <sashal@...nel.org>
Subject: [PATCH 4.9 103/218] mxser: fix xmit_buf leak in activate when LSR == 0xff
From: Jiri Slaby <jslaby@...e.cz>
[ Upstream commit cd3a4907ee334b40d7aa880c7ab310b154fd5cd4 ]
When LSR is 0xff in ->activate() (rather unlike), we return an error.
Provided ->shutdown() is not called when ->activate() fails, nothing
actually frees the buffer in this case.
Fix this by properly freeing the buffer in a designated label. We jump
there also from the "!info->type" if now too.
Fixes: 6769140d3047 ("tty: mxser: use the tty_port_open method")
Signed-off-by: Jiri Slaby <jslaby@...e.cz>
Link: https://lore.kernel.org/r/20220124071430.14907-6-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
drivers/tty/mxser.c | 15 +++++++++++----
1 file changed, 11 insertions(+), 4 deletions(-)
diff --git a/drivers/tty/mxser.c b/drivers/tty/mxser.c
index 69294ae154be..ea7f4af85d58 100644
--- a/drivers/tty/mxser.c
+++ b/drivers/tty/mxser.c
@@ -860,6 +860,7 @@ static int mxser_activate(struct tty_port *port, struct tty_struct *tty)
struct mxser_port *info = container_of(port, struct mxser_port, port);
unsigned long page;
unsigned long flags;
+ int ret;
page = __get_free_page(GFP_KERNEL);
if (!page)
@@ -869,9 +870,9 @@ static int mxser_activate(struct tty_port *port, struct tty_struct *tty)
if (!info->ioaddr || !info->type) {
set_bit(TTY_IO_ERROR, &tty->flags);
- free_page(page);
spin_unlock_irqrestore(&info->slock, flags);
- return 0;
+ ret = 0;
+ goto err_free_xmit;
}
info->port.xmit_buf = (unsigned char *) page;
@@ -897,8 +898,10 @@ static int mxser_activate(struct tty_port *port, struct tty_struct *tty)
if (capable(CAP_SYS_ADMIN)) {
set_bit(TTY_IO_ERROR, &tty->flags);
return 0;
- } else
- return -ENODEV;
+ }
+
+ ret = -ENODEV;
+ goto err_free_xmit;
}
/*
@@ -943,6 +946,10 @@ static int mxser_activate(struct tty_port *port, struct tty_struct *tty)
spin_unlock_irqrestore(&info->slock, flags);
return 0;
+err_free_xmit:
+ free_page(page);
+ info->port.xmit_buf = NULL;
+ return ret;
}
/*
--
2.34.1
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