KASAN: slab-out-of-bounds Read in technisat_usb2_rc_query

From: syzbot
Date: Sun Apr 14 2019 - 16:06:17 EST

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Hello,

syzbot found the following crash on:

HEAD commit: 9a33b369 usb-fuzzer: main usb gadget fuzzer driver
git tree: https://github.com/google/kasan/tree/usb-fuzzer
console output: https://syzkaller.appspot.com/x/log.txt?x=1441219f200000
kernel config: https://syzkaller.appspot.com/x/.config?x=23e37f59d94ddd15
dashboard link: https://syzkaller.appspot.com/bug?extid=eaaaf38a95427be88f4b
compiler: gcc (GCC) 9.0.0 20181231 (experimental)
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=174a67bb200000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=17aa2023200000

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+eaaaf38a95427be88f4b@xxxxxxxxxxxxxxxxxxxxxxxxx

rc rc1: Technisat SkyStar USB HD (DVB-S/S2) as /devices/platform/dummy_hcd.0/usb1/1-1/rc/rc1
input: Technisat SkyStar USB HD (DVB-S/S2) as /devices/platform/dummy_hcd.0/usb1/1-1/rc/rc1/input10
rc rc1: lirc_dev: driver technisat-usb2 registered at minor = 1, raw IR receiver, no transmitter
dvb-usb: schedule remote query interval to 100 msecs.
==================================================================
BUG: KASAN: slab-out-of-bounds in technisat_usb2_get_ir drivers/media/usb/dvb-usb/technisat-usb2.c:664 [inline]
BUG: KASAN: slab-out-of-bounds in technisat_usb2_rc_query+0x5fa/0x660 drivers/media/usb/dvb-usb/technisat-usb2.c:679
Read of size 1 at addr ffff8880a8791ea8 by task kworker/0:1/12

CPU: 0 PID: 12 Comm: kworker/0:1 Not tainted 5.1.0-rc4-319354-g9a33b36 #3
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: events dvb_usb_read_remote_control
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0xe8/0x16e lib/dump_stack.c:113
print_address_description+0x6c/0x236 mm/kasan/report.c:187
kasan_report.cold+0x1a/0x3c mm/kasan/report.c:317
technisat_usb2_get_ir drivers/media/usb/dvb-usb/technisat-usb2.c:664 [inline]
technisat_usb2_rc_query+0x5fa/0x660 drivers/media/usb/dvb-usb/technisat-usb2.c:679
dvb_usb_read_remote_control drivers/media/usb/dvb-usb-v2/dvb_usb_core.c:128 [inline]
dvb_usb_read_remote_control+0xe5/0x1c0 drivers/media/usb/dvb-usb-v2/dvb_usb_core.c:105
process_one_work+0x90f/0x1580 kernel/workqueue.c:2269
worker_thread+0x9b/0xe20 kernel/workqueue.c:2415
kthread+0x313/0x420 kernel/kthread.c:253
ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352

Allocated by task 615:
set_track mm/kasan/common.c:87 [inline]
__kasan_kmalloc mm/kasan/common.c:497 [inline]
__kasan_kmalloc.constprop.0+0xbf/0xd0 mm/kasan/common.c:470
dvb_usb_init drivers/media/usb/dvb-usb/dvb-usb-init.c:152 [inline]
dvb_usb_device_init.cold+0x317/0x10b3 drivers/media/usb/dvb-usb/dvb-usb-init.c:277
technisat_usb2_probe+0x82/0x2d0 drivers/media/usb/dvb-usb/technisat-usb2.c:763
usb_probe_interface+0x31d/0x820 drivers/usb/core/driver.c:361
really_probe+0x2da/0xb10 drivers/base/dd.c:509
driver_probe_device+0x21d/0x350 drivers/base/dd.c:671
__device_attach_driver+0x1d8/0x290 drivers/base/dd.c:778
bus_for_each_drv+0x163/0x1e0 drivers/base/bus.c:454
__device_attach+0x223/0x3a0 drivers/base/dd.c:844
bus_probe_device+0x1f1/0x2a0 drivers/base/bus.c:514
device_add+0xad2/0x16e0 drivers/base/core.c:2106
usb_set_configuration+0xdf7/0x1740 drivers/usb/core/message.c:2021
generic_probe+0xa2/0xda drivers/usb/core/generic.c:210
usb_probe_device+0xc0/0x150 drivers/usb/core/driver.c:266
really_probe+0x2da/0xb10 drivers/base/dd.c:509
driver_probe_device+0x21d/0x350 drivers/base/dd.c:671
__device_attach_driver+0x1d8/0x290 drivers/base/dd.c:778
bus_for_each_drv+0x163/0x1e0 drivers/base/bus.c:454
__device_attach+0x223/0x3a0 drivers/base/dd.c:844
bus_probe_device+0x1f1/0x2a0 drivers/base/bus.c:514
device_add+0xad2/0x16e0 drivers/base/core.c:2106
usb_new_device.cold+0x537/0xccf drivers/usb/core/hub.c:2534
hub_port_connect drivers/usb/core/hub.c:5089 [inline]
hub_port_connect_change drivers/usb/core/hub.c:5204 [inline]
port_event drivers/usb/core/hub.c:5350 [inline]
hub_event+0x138e/0x3b00 drivers/usb/core/hub.c:5432
process_one_work+0x90f/0x1580 kernel/workqueue.c:2269
worker_thread+0x9b/0xe20 kernel/workqueue.c:2415
kthread+0x313/0x420 kernel/kthread.c:253
ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352

Freed by task 1:
set_track mm/kasan/common.c:87 [inline]
__kasan_slab_free+0x130/0x180 mm/kasan/common.c:459
slab_free_hook mm/slub.c:1429 [inline]
slab_free_freelist_hook+0x5e/0x140 mm/slub.c:1456
slab_free mm/slub.c:3003 [inline]
kfree+0xce/0x290 mm/slub.c:3958
krealloc+0x7d/0xc0 mm/slab_common.c:1570
add_sysfs_param.isra.0+0xcd/0x930 kernel/params.c:633
kernel_add_sysfs_param kernel/params.c:794 [inline]
param_sysfs_builtin kernel/params.c:833 [inline]
param_sysfs_init+0x364/0x435 kernel/params.c:954
do_one_initcall+0xde/0x597 init/main.c:901
do_initcall_level init/main.c:969 [inline]
do_initcalls init/main.c:977 [inline]
do_basic_setup init/main.c:995 [inline]
kernel_init_freeable+0x4da/0x5c7 init/main.c:1150
kernel_init+0x12/0x1ca init/main.c:1068
ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352

The buggy address belongs to the object at ffff8880a8791dc0
which belongs to the cache kmalloc-256 of size 256
The buggy address is located 232 bytes inside of
256-byte region [ffff8880a8791dc0, ffff8880a8791ec0)
The buggy address belongs to the page:
page:ffffea0002a1e440 count:1 mapcount:0 mapping:ffff88812c3f4e00 index:0x0
flags: 0xfff00000000200(slab)
raw: 00fff00000000200 dead000000000100 dead000000000200 ffff88812c3f4e00
raw: 0000000000000000 00000000000c000c 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
ffff8880a8791d80: fc fc fc fc fc fc fc fc 00 00 00 00 00 00 00 00
ffff8880a8791e00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00

ffff8880a8791e80: 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc

^
ffff8880a8791f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff8880a8791f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================

---
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