KASAN: slab-out-of-bounds Read in garmin_read_process

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit: e17994d1 usb: core: kcov: collect coverage from usb comple..
git tree: https://github.com/google/kasan.git usb-fuzzer
console output: https://syzkaller.appspot.com/x/log.txt?x=16255ce5e00000
kernel config: https://syzkaller.appspot.com/x/.config?x=5d64370c438bc60
dashboard link: https://syzkaller.appspot.com/bug?extid=d29e9263e13ce0b9f4fd
compiler: gcc (GCC) 9.0.0 20181231 (experimental)
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1376a3f9e00000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=14c65fe3e00000

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+d29e92...@syzkaller.appspotmail.com

==================================================================
BUG: KASAN: slab-out-of-bounds in __le32_to_cpup include/uapi/linux/byteorder/little_endian.h:58 [inline]
BUG: KASAN: slab-out-of-bounds in getLayerId drivers/usb/serial/garmin_gps.c:208 [inline]
BUG: KASAN: slab-out-of-bounds in garmin_read_process+0x1b0/0x2e0 drivers/usb/serial/garmin_gps.c:1142
Read of size 4 at addr ffff8881ca74abe8 by task swapper/1/0

CPU: 1 PID: 0 Comm: swapper/1 Not tainted 5.6.0-rc5-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
<IRQ>
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0xef/0x16e lib/dump_stack.c:118
print_address_description.constprop.0.cold+0xd3/0x314 mm/kasan/report.c:374
__kasan_report.cold+0x37/0x77 mm/kasan/report.c:506
kasan_report+0xe/0x20 mm/kasan/common.c:641
__le32_to_cpup include/uapi/linux/byteorder/little_endian.h:58 [inline]
getLayerId drivers/usb/serial/garmin_gps.c:208 [inline]
garmin_read_process+0x1b0/0x2e0 drivers/usb/serial/garmin_gps.c:1142
garmin_read_int_callback+0x19f/0x746 drivers/usb/serial/garmin_gps.c:1279
__usb_hcd_giveback_urb+0x29a/0x550 drivers/usb/core/hcd.c:1650
usb_hcd_giveback_urb+0x368/0x420 drivers/usb/core/hcd.c:1716
dummy_timer+0x1258/0x32ae drivers/usb/gadget/udc/dummy_hcd.c:1966


---
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[Oliver Neukum]

Am Samstag, den 21.03.2020, 06:40 -0700 schrieb syzbot:
> Hello,
>
> syzbot found the following crash on:
>
> HEAD commit: e17994d1 usb: core: kcov: collect coverage from usb comple..
> git tree: https://github.com/google/kasan.git usb-fuzzer
> console output: https://syzkaller.appspot.com/x/log.txt?x=16255ce5e00000
> kernel config: https://syzkaller.appspot.com/x/.config?x=5d64370c438bc60
> dashboard link: https://syzkaller.appspot.com/bug?extid=d29e9263e13ce0b9f4fd
> compiler: gcc (GCC) 9.0.0 20181231 (experimental)
> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1376a3f9e00000
> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=14c65fe3e00000

#syz test: https://github.com/google/kasan.git e17994d1

[syzbot]

Hello,

syzbot has tested the proposed patch and the reproducer did not trigger crash:

Reported-and-tested-by: syzbot+d29e92...@syzkaller.appspotmail.com

Tested on:

commit: e17994d1 usb: core: kcov: collect coverage from usb comple..
git tree: https://github.com/google/kasan.git

kernel config: https://syzkaller.appspot.com/x/.config?x=5d64370c438bc60
dashboard link: https://syzkaller.appspot.com/bug?extid=d29e9263e13ce0b9f4fd
compiler: gcc (GCC) 9.0.0 20181231 (experimental)

patch: https://syzkaller.appspot.com/x/patch.diff?x=17315ad3e00000

Note: testing is done by a robot and is best-effort only.