All of lore.kernel.org
 help / color / mirror / Atom feed
From: Xiyu Yang <xiyuyang19@fudan.edu.cn>
To: Rob Springer <rspringer@google.com>,
	Todd Poynor <toddpoynor@google.com>,
	Ben Chan <benchan@chromium.org>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	devel@driverdev.osuosl.org, linux-kernel@vger.kernel.org
Cc: yuanxzhang@fudan.edu.cn, kjlu@umn.edu,
	Xiyu Yang <xiyuyang19@fudan.edu.cn>,
	Xin Tan <tanxin.ctf@gmail.com>
Subject: [PATCH] staging: gasket: Fix mapping refcnt leak when put attribute fails
Date: Thu, 23 Apr 2020 13:14:55 +0800	[thread overview]
Message-ID: <1587618895-13660-1-git-send-email-xiyuyang19@fudan.edu.cn> (raw)

gasket_sysfs_put_attr() invokes get_mapping(), which returns a reference
of the specified gasket_sysfs_mapping object to "mapping" with increased
refcnt.

When gasket_sysfs_put_attr() returns, local variable "mapping" becomes
invalid, so the refcount should be decreased to keep refcount balanced.

The reference counting issue happens in one path of
gasket_sysfs_put_attr(). When mapping attribute is unknown, the function
forgets to decrease the refcnt increased by get_mapping(), causing a
refcnt leak.

Fix this issue by calling put_mapping() when put attribute fails due to
unknown attribute.

Signed-off-by: Xiyu Yang <xiyuyang19@fudan.edu.cn>
Signed-off-by: Xin Tan <tanxin.ctf@gmail.com>
---
 drivers/staging/gasket/gasket_sysfs.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/staging/gasket/gasket_sysfs.c b/drivers/staging/gasket/gasket_sysfs.c
index a2d67c28f530..f24edc38c27b 100644
--- a/drivers/staging/gasket/gasket_sysfs.c
+++ b/drivers/staging/gasket/gasket_sysfs.c
@@ -340,6 +340,7 @@ void gasket_sysfs_put_attr(struct device *device,
 
 	dev_err(device, "Unable to put unknown attribute: %s\n",
 		attr->attr.attr.name);
+	put_mapping(mapping);
 }
 EXPORT_SYMBOL(gasket_sysfs_put_attr);
 
-- 
2.7.4


WARNING: multiple messages have this Message-ID (diff)
From: Xiyu Yang <xiyuyang19@fudan.edu.cn>
To: Rob Springer <rspringer@google.com>,
	Todd Poynor <toddpoynor@google.com>,
	Ben Chan <benchan@chromium.org>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	devel@driverdev.osuosl.org, linux-kernel@vger.kernel.org
Cc: Xin Tan <tanxin.ctf@gmail.com>,
	yuanxzhang@fudan.edu.cn, kjlu@umn.edu,
	Xiyu Yang <xiyuyang19@fudan.edu.cn>
Subject: [PATCH] staging: gasket: Fix mapping refcnt leak when put attribute fails
Date: Thu, 23 Apr 2020 13:14:55 +0800	[thread overview]
Message-ID: <1587618895-13660-1-git-send-email-xiyuyang19@fudan.edu.cn> (raw)

gasket_sysfs_put_attr() invokes get_mapping(), which returns a reference
of the specified gasket_sysfs_mapping object to "mapping" with increased
refcnt.

When gasket_sysfs_put_attr() returns, local variable "mapping" becomes
invalid, so the refcount should be decreased to keep refcount balanced.

The reference counting issue happens in one path of
gasket_sysfs_put_attr(). When mapping attribute is unknown, the function
forgets to decrease the refcnt increased by get_mapping(), causing a
refcnt leak.

Fix this issue by calling put_mapping() when put attribute fails due to
unknown attribute.

Signed-off-by: Xiyu Yang <xiyuyang19@fudan.edu.cn>
Signed-off-by: Xin Tan <tanxin.ctf@gmail.com>
---
 drivers/staging/gasket/gasket_sysfs.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/staging/gasket/gasket_sysfs.c b/drivers/staging/gasket/gasket_sysfs.c
index a2d67c28f530..f24edc38c27b 100644
--- a/drivers/staging/gasket/gasket_sysfs.c
+++ b/drivers/staging/gasket/gasket_sysfs.c
@@ -340,6 +340,7 @@ void gasket_sysfs_put_attr(struct device *device,
 
 	dev_err(device, "Unable to put unknown attribute: %s\n",
 		attr->attr.attr.name);
+	put_mapping(mapping);
 }
 EXPORT_SYMBOL(gasket_sysfs_put_attr);
 
-- 
2.7.4

_______________________________________________
devel mailing list
devel@linuxdriverproject.org
http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel

             reply	other threads:[~2020-04-23  5:16 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-04-23  5:14 Xiyu Yang [this message]
2020-04-23  5:14 ` [PATCH] staging: gasket: Fix mapping refcnt leak when put attribute fails Xiyu Yang

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=1587618895-13660-1-git-send-email-xiyuyang19@fudan.edu.cn \
    --to=xiyuyang19@fudan.edu.cn \
    --cc=benchan@chromium.org \
    --cc=devel@driverdev.osuosl.org \
    --cc=gregkh@linuxfoundation.org \
    --cc=kjlu@umn.edu \
    --cc=linux-kernel@vger.kernel.org \
    --cc=rspringer@google.com \
    --cc=tanxin.ctf@gmail.com \
    --cc=toddpoynor@google.com \
    --cc=yuanxzhang@fudan.edu.cn \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.