This is a note to let you know that I've just added the patch titled
HID: hidraw: correctly deallocate memory on device disconnect
to the 3.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
hid-hidraw-correctly-deallocate-memory-on-device-disconnect.patch
and it can be found in the queue-3.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 384a27453c74b2fc27063dd287acf72550a1ad0f Mon Sep 17 00:00:00 2001
From: Manoj Chourasia <mchourasia@xxxxxxxxxx>
Date: Mon, 22 Jul 2013 15:33:13 +0530
Subject: HID: hidraw: correctly deallocate memory on device disconnect
From: Manoj Chourasia <mchourasia@xxxxxxxxxx>
commit 212a871a3934beccf43431608c27ed2e05a476ec upstream.
This changes puts the commit 4fe9f8e203f back in place
with the fixes for slab corruption because of the commit.
When a device is unplugged, wait for all processes that
have opened the device to close before deallocating the device.
This commit was solving kernel crash because of the corruption in
rb tree of vmalloc. The rootcause was the device data pointer was
geting excessed after the memory associated with hidraw was freed.
The commit 4fe9f8e203f was buggy as it was also freeing the hidraw
first and then calling delete operation on the list associated with
that hidraw leading to slab corruption.
Signed-off-by: Manoj Chourasia <mchourasia@xxxxxxxxxx>
Tested-by: Peter Wu <lekensteyn@xxxxxxxxx>
Signed-off-by: Jiri Kosina <jkosina@xxxxxxx>
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
Cc: Yijing Wang <wangyijing@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/hid/hidraw.c | 60 +++++++++++++++++++++------------------------------
1 file changed, 25 insertions(+), 35 deletions(-)
--- a/drivers/hid/hidraw.c
+++ b/drivers/hid/hidraw.c
@@ -113,7 +113,7 @@ static ssize_t hidraw_send_report(struct
__u8 *buf;
int ret = 0;
- if (!hidraw_table[minor]) {
+ if (!hidraw_table[minor] || !hidraw_table[minor]->exist) {
ret = -ENODEV;
goto out;
}
@@ -261,7 +261,7 @@ static int hidraw_open(struct inode *ino
}
mutex_lock(&minors_lock);
- if (!hidraw_table[minor]) {
+ if (!hidraw_table[minor] || !hidraw_table[minor]->exist) {
err = -ENODEV;
goto out_unlock;
}
@@ -295,39 +295,38 @@ out:
}
+static void drop_ref(struct hidraw *hidraw, int exists_bit)
+{
+ if (exists_bit) {
+ hid_hw_close(hidraw->hid);
+ hidraw->exist = 0;
+ if (hidraw->open)
+ wake_up_interruptible(&hidraw->wait);
+ } else {
+ --hidraw->open;
+ }
+
+ if (!hidraw->open && !hidraw->exist) {
+ device_destroy(hidraw_class, MKDEV(hidraw_major, hidraw->minor));
+ hidraw_table[hidraw->minor] = NULL;
+ kfree(hidraw);
+ }
+}
+
static int hidraw_release(struct inode * inode, struct file * file)
{
unsigned int minor = iminor(inode);
- struct hidraw *dev;
struct hidraw_list *list = file->private_data;
- int ret;
- int i;
mutex_lock(&minors_lock);
- if (!hidraw_table[minor]) {
- ret = -ENODEV;
- goto unlock;
- }
list_del(&list->node);
- dev = hidraw_table[minor];
- if (!--dev->open) {
- if (list->hidraw->exist) {
- hid_hw_power(dev->hid, PM_HINT_NORMAL);
- hid_hw_close(dev->hid);
- } else {
- kfree(list->hidraw);
- }
- }
-
- for (i = 0; i < HIDRAW_BUFFER_SIZE; ++i)
- kfree(list->buffer[i].value);
kfree(list);
- ret = 0;
-unlock:
- mutex_unlock(&minors_lock);
- return ret;
+ drop_ref(hidraw_table[minor], 0);
+
+ mutex_unlock(&minors_lock);
+ return 0;
}
static long hidraw_ioctl(struct file *file, unsigned int cmd,
@@ -531,18 +530,9 @@ void hidraw_disconnect(struct hid_device
struct hidraw *hidraw = hid->hidraw;
mutex_lock(&minors_lock);
- hidraw->exist = 0;
-
- device_destroy(hidraw_class, MKDEV(hidraw_major, hidraw->minor));
- hidraw_table[hidraw->minor] = NULL;
+ drop_ref(hidraw, 1);
- if (hidraw->open) {
- hid_hw_close(hid);
- wake_up_interruptible(&hidraw->wait);
- } else {
- kfree(hidraw);
- }
mutex_unlock(&minors_lock);
}
EXPORT_SYMBOL_GPL(hidraw_disconnect);
Patches currently in stable-queue which might be from mchourasia@xxxxxxxxxx are
queue-3.4/hid-hidraw-correctly-deallocate-memory-on-device-disconnect.patch
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