| From | Greg Kroah-Hartman <> | Subject | [PATCH 4.4 38/86] Bluetooth: vhci: purge unhandled skbs | Date | Mon, 30 May 2016 13:49:27 -0700 |
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4.4-stable review patch. If anyone has any objections, please let me know.
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From: Jiri Slaby <jslaby@suse.cz>
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>
--- drivers/bluetooth/hci_vhci.c | 1 + 1 file changed, 1 insertion(+)
--- a/drivers/bluetooth/hci_vhci.c +++ b/drivers/bluetooth/hci_vhci.c @@ -344,6 +344,7 @@ static int vhci_release(struct inode *in hci_free_dev(hdev); } + skb_queue_purge(&data->readq); file->private_data = NULL; kfree(data);
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