From: Jiri Slaby <jslaby@suse.cz>
Date: Sat, 19 Mar 2016 10:49:43 +0000 (+0100)
Subject: Bluetooth: vhci: purge unhandled skbs
X-Git-Tag: firefly_0821_release~176^2~4^2~43^2~49
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=3295bfd3f1f39f959dba17c1637e2741f7b3c4a3;p=firefly-linux-kernel-4.4.55.git
Bluetooth: vhci: purge unhandled skbs
commit 13407376b255325fa817798800117a839f3aa055 upstream.
The write handler allocates skbs and queues them into data->readq.
Read side should read them, if there is any. If there is none, skbs
should be dropped by hdev->flush. But this happens only if the device
is HCI_UP, i.e. hdev->power_on work was triggered already. When it was
not, skbs stay allocated in the queue when /dev/vhci is closed. So
purge the queue in ->release.
Program to reproduce:
#include <err.h>
#include <fcntl.h>
#include <stdio.h>
#include <unistd.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <sys/uio.h>
int main()
{
char buf[] = { 0xff, 0 };
struct iovec iov = {
.iov_base = buf,
.iov_len = sizeof(buf),
};
int fd;
while (1) {
fd = open("/dev/vhci", O_RDWR);
if (fd < 0)
err(1, "open");
usleep(50);
if (writev(fd, &iov, 1) < 0)
err(1, "writev");
usleep(50);
close(fd);
}
return 0;
}
Result:
kmemleak: 4609 new suspected memory leaks
unreferenced object 0xffff88059f4d5440 (size 232):
comm "vhci", pid 1084, jiffies 4294912542 (age 37569.296s)
hex dump (first 32 bytes):
20 f0 23 87 05 88 ff ff 20 f0 23 87 05 88 ff ff .#..... .#.....
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
...
[<ffffffff81ece010>] __alloc_skb+0x0/0x5a0
[<ffffffffa021886c>] vhci_create_device+0x5c/0x580 [hci_vhci]
[<ffffffffa0219436>] vhci_write+0x306/0x4c8 [hci_vhci]
Fixes: 23424c0d31 (Bluetooth: Add support creating virtual AMP controllers)
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
diff --git a/drivers/bluetooth/hci_vhci.c b/drivers/bluetooth/hci_vhci.c
index b6fb499a4531..4987f8b648f6 100644
--- a/drivers/bluetooth/hci_vhci.c
+++ b/drivers/bluetooth/hci_vhci.c
@@ -344,6 +344,7 @@ static int vhci_release(struct inode *inode, struct file *file)
hci_free_dev(hdev);
}
+ skb_queue_purge(&data->readq);
file->private_data = NULL;
kfree(data);