From: Jiri Slaby jslaby@suse.cz
stable inclusion from stable-v5.10.110 commit 2cd05c38a27bee7fb42aa4d43174d68ac55dac0f bugzilla: https://gitee.com/openeuler/kernel/issues/I574AL
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...
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[ 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@suse.cz Link: https://lore.kernel.org/r/20220124071430.14907-6-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Sasha Levin sashal@kernel.org Signed-off-by: Yu Liao liaoyu15@huawei.com Reviewed-by: Wei Li liwei391@huawei.com Signed-off-by: Zheng Zengkai zhengzengkai@huawei.com --- 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 3703987c4666..8344265a1948 100644 --- a/drivers/tty/mxser.c +++ b/drivers/tty/mxser.c @@ -858,6 +858,7 @@ 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) @@ -867,9 +868,9 @@ 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;
@@ -895,8 +896,10 @@ 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; }
/* @@ -941,6 +944,10 @@ 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; }
/*