mirror of https://gitee.com/openkylin/linux.git
373a32c848
Both vhci_get_user and vhci_release race with open_timeout work. They
both contain cancel_delayed_work_sync, but do not test whether the
work actually created hdev or not. Since the work can be in progress
and _sync will wait for finishing it, we can have data->hdev allocated
when cancel_delayed_work_sync returns. But the call sites do 'if
(data->hdev)' *before* cancel_delayed_work_sync.
As a result:
* vhci_get_user allocates a second hdev and puts it into
data->hdev. The former is leaked.
* vhci_release does not release data->hdev properly as it thinks there
is none.
Fix both cases by moving the actual test *after* the call to
cancel_delayed_work_sync.
This can be hit by this program:
#include <err.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include <unistd.h>
#include <sys/stat.h>
#include <sys/types.h>
int main(int argc, char **argv)
{
int fd;
srand(time(NULL));
while (1) {
const int delta = (rand() % 200 - 100) * 100;
fd = open("/dev/vhci", O_RDWR);
if (fd < 0)
err(1, "open");
usleep(1000000 + delta);
close(fd);
}
return 0;
}
And the result is:
BUG: KASAN: use-after-free in skb_queue_tail+0x13e/0x150 at addr ffff88006b0c1228
Read of size 8 by task kworker/u13:1/32068
=============================================================================
BUG kmalloc-192 (Tainted: G E ): kasan: bad access detected
-----------------------------------------------------------------------------
Disabling lock debugging due to kernel taint
INFO: Allocated in vhci_open+0x50/0x330 [hci_vhci] age=260 cpu=3 pid=32040
...
kmem_cache_alloc_trace+0x150/0x190
vhci_open+0x50/0x330 [hci_vhci]
misc_open+0x35b/0x4e0
chrdev_open+0x23b/0x510
...
INFO: Freed in vhci_release+0xa4/0xd0 [hci_vhci] age=9 cpu=2 pid=32040
...
__slab_free+0x204/0x310
vhci_release+0xa4/0xd0 [hci_vhci]
...
INFO: Slab 0xffffea0001ac3000 objects=16 used=13 fp=0xffff88006b0c1e00 flags=0x5fffff80004080
INFO: Object 0xffff88006b0c1200 @offset=4608 fp=0xffff88006b0c0600
Bytes b4 ffff88006b0c11f0: 09 df 00 00 01 00 00 00 00 00 00 00 00 00 00 00 ................
Object ffff88006b0c1200: 00 06 0c 6b 00 88 ff ff 00 00 00 00 00 00 00 00 ...k............
Object ffff88006b0c1210: 10 12 0c 6b 00 88 ff ff 10 12 0c 6b 00 88 ff ff ...k.......k....
Object ffff88006b0c1220: c0 46 c2 6b 00 88 ff ff c0 46 c2 6b 00 88 ff ff .F.k.....F.k....
Object ffff88006b0c1230: 01 00 00 00 01 00 00 00 e0 ff ff ff 0f 00 00 00 ................
Object ffff88006b0c1240: 40 12 0c 6b 00 88 ff ff 40 12 0c 6b 00 88 ff ff @..k....@..k....
Object ffff88006b0c1250: 50 0d 6e a0 ff ff ff ff 00 02 00 00 00 00 ad de P.n.............
Object ffff88006b0c1260: 00 00 00 00 00 00 00 00 ab 62 02 00 01 00 00 00 .........b......
Object ffff88006b0c1270: 90 b9 19 81 ff ff ff ff 38 12 0c 6b 00 88 ff ff ........8..k....
Object ffff88006b0c1280: 03 00 20 00 ff ff ff ff ff ff ff ff 00 00 00 00 .. .............
Object ffff88006b0c1290: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
Object ffff88006b0c12a0: 00 00 00 00 00 00 00 00 00 80 cd 3d 00 88 ff ff ...........=....
Object ffff88006b0c12b0: 00 20 00 00 00 00 00 00 00 00 00 00 00 00 00 00 . ..............
Redzone ffff88006b0c12c0: bb bb bb bb bb bb bb bb ........
Padding ffff88006b0c13f8: 00 00 00 00 00 00 00 00 ........
CPU: 3 PID: 32068 Comm: kworker/u13:1 Tainted: G B E 4.4.6-0-default #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.8.1-0-g4adadbd-20151112_172657-sheep25 04/01/2014
Workqueue: hci0 hci_cmd_work [bluetooth]
00000000ffffffff ffffffff81926cfa ffff88006be37c68 ffff88006bc27180
ffff88006b0c1200 ffff88006b0c1234 ffffffff81577993 ffffffff82489320
ffff88006bc24240 0000000000000046 ffff88006a100000 000000026e51eb80
Call Trace:
...
[<ffffffff81ec8ebe>] ? skb_queue_tail+0x13e/0x150
[<ffffffffa06e027c>] ? vhci_send_frame+0xac/0x100 [hci_vhci]
[<ffffffffa0c61268>] ? hci_send_frame+0x188/0x320 [bluetooth]
[<ffffffffa0c61515>] ? hci_cmd_work+0x115/0x310 [bluetooth]
[<ffffffff811a1375>] ? process_one_work+0x815/0x1340
[<ffffffff811a1f85>] ? worker_thread+0xe5/0x11f0
[<ffffffff811a1ea0>] ? process_one_work+0x1340/0x1340
[<ffffffff811b3c68>] ? kthread+0x1c8/0x230
...
Memory state around the buggy address:
ffff88006b0c1100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff88006b0c1180: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff88006b0c1200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff88006b0c1280: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
ffff88006b0c1300: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
Fixes:
|
||
|---|---|---|
| .. | ||
| accessibility | ||
| acpi | ||
| amba | ||
| android | ||
| ata | ||
| atm | ||
| auxdisplay | ||
| base | ||
| bcma | ||
| block | ||
| bluetooth | ||
| bus | ||
| cdrom | ||
| char | ||
| clk | ||
| clocksource | ||
| connector | ||
| cpufreq | ||
| cpuidle | ||
| crypto | ||
| dca | ||
| devfreq | ||
| dio | ||
| dma | ||
| dma-buf | ||
| edac | ||
| eisa | ||
| extcon | ||
| firewire | ||
| firmware | ||
| fmc | ||
| fpga | ||
| gpio | ||
| gpu | ||
| hid | ||
| hsi | ||
| hv | ||
| hwmon | ||
| hwspinlock | ||
| hwtracing | ||
| i2c | ||
| ide | ||
| idle | ||
| iio | ||
| infiniband | ||
| input | ||
| iommu | ||
| ipack | ||
| irqchip | ||
| isdn | ||
| leds | ||
| lguest | ||
| lightnvm | ||
| macintosh | ||
| mailbox | ||
| mcb | ||
| md | ||
| media | ||
| memory | ||
| memstick | ||
| message | ||
| mfd | ||
| misc | ||
| mmc | ||
| mtd | ||
| net | ||
| nfc | ||
| ntb | ||
| nubus | ||
| nvdimm | ||
| nvme | ||
| nvmem | ||
| of | ||
| oprofile | ||
| parisc | ||
| parport | ||
| pci | ||
| pcmcia | ||
| perf | ||
| phy | ||
| pinctrl | ||
| platform | ||
| pnp | ||
| power | ||
| powercap | ||
| pps | ||
| ps3 | ||
| ptp | ||
| pwm | ||
| rapidio | ||
| ras | ||
| regulator | ||
| remoteproc | ||
| reset | ||
| rpmsg | ||
| rtc | ||
| s390 | ||
| sbus | ||
| scsi | ||
| sfi | ||
| sh | ||
| sn | ||
| soc | ||
| spi | ||
| spmi | ||
| ssb | ||
| staging | ||
| target | ||
| tc | ||
| thermal | ||
| thunderbolt | ||
| tty | ||
| uio | ||
| usb | ||
| uwb | ||
| vfio | ||
| vhost | ||
| video | ||
| virt | ||
| virtio | ||
| vlynq | ||
| vme | ||
| w1 | ||
| watchdog | ||
| xen | ||
| zorro | ||
| Kconfig | ||
| Makefile | ||