[syzbot] KASAN: use-after-free Read in em28xx_close_extension

From: syzbot
Date: Wed Jul 14 2021 - 10:27:21 EST


Hello,

syzbot found the following issue on:

HEAD commit: 3dbdb38e Merge branch 'for-5.14' of git://git.kernel.org/p..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=158cf1e2300000
kernel config: https://syzkaller.appspot.com/x/.config?x=a1fcf15a09815757
dashboard link: https://syzkaller.appspot.com/bug?extid=005037419ebdf14e1d87
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=169746b0300000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=157e89c4300000

The issue was bisected to:

commit ac5688637144644f06ed1f3c6d4dd8bb7db96020
Author: Igor Matheus Andrade Torrente <igormtorrente@xxxxxxxxx>
Date: Tue May 4 18:32:49 2021 +0000

media: em28xx: Fix possible memory leak of em28xx struct

bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=1742cffc300000
final oops: https://syzkaller.appspot.com/x/report.txt?x=14c2cffc300000
console output: https://syzkaller.appspot.com/x/log.txt?x=10c2cffc300000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+005037419ebdf14e1d87@xxxxxxxxxxxxxxxxxxxxxxxxx
Fixes: ac5688637144 ("media: em28xx: Fix possible memory leak of em28xx struct")

usb 1-1: bad CDC descriptors
usb 1-1: USB disconnect, device number 2
em28xx 1-1:64.138: Disconnecting em28xx
em28xx 1-1:64.138: Closing input extension
em28xx 1-1:64.138: Freeing device
==================================================================
BUG: KASAN: use-after-free in __list_del_entry_valid+0xcc/0xf0 lib/list_debug.c:42
Read of size 8 at addr ffff888021aa8258 by task kworker/1:2/3456

CPU: 1 PID: 3456 Comm: kworker/1:2 Not tainted 5.13.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: usb_hub_wq hub_event
Call Trace:
__dump_stack lib/dump_stack.c:79 [inline]
dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:96
print_address_description.constprop.0.cold+0x6c/0x309 mm/kasan/report.c:233
__kasan_report mm/kasan/report.c:419 [inline]
kasan_report.cold+0x83/0xdf mm/kasan/report.c:436
__list_del_entry_valid+0xcc/0xf0 lib/list_debug.c:42
__list_del_entry include/linux/list.h:132 [inline]
list_del include/linux/list.h:146 [inline]
em28xx_close_extension+0x10b/0x2a0 drivers/media/usb/em28xx/em28xx-core.c:1146
em28xx_usb_disconnect.cold+0x14b/0x237 drivers/media/usb/em28xx/em28xx-cards.c:4140
usb_unbind_interface+0x1d8/0x8d0 drivers/usb/core/driver.c:458
__device_release_driver+0x3bd/0x6f0 drivers/base/dd.c:1181
device_release_driver_internal drivers/base/dd.c:1212 [inline]
device_release_driver+0x26/0x40 drivers/base/dd.c:1235
bus_remove_device+0x2eb/0x5a0 drivers/base/bus.c:533
device_del+0x502/0xd40 drivers/base/core.c:3512
usb_disable_device+0x35b/0x7b0 drivers/usb/core/message.c:1413
usb_disconnect.cold+0x27a/0x78e drivers/usb/core/hub.c:2221
hub_port_connect drivers/usb/core/hub.c:5129 [inline]
hub_port_connect_change drivers/usb/core/hub.c:5418 [inline]
port_event drivers/usb/core/hub.c:5564 [inline]
hub_event+0x1c9c/0x4330 drivers/usb/core/hub.c:5646
process_one_work+0x98d/0x1630 kernel/workqueue.c:2276
process_scheduled_works kernel/workqueue.c:2338 [inline]
worker_thread+0x85c/0x11f0 kernel/workqueue.c:2424
kthread+0x3e5/0x4d0 kernel/kthread.c:319
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295

The buggy address belongs to the page:
page:ffffea000086aa00 refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x21aa8
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000000 ffffea0000ac0d08 ffff8880b9d3b288 0000000000000000
raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as freed
page last allocated via order 2, migratetype Unmovable, gfp_mask 0x40dc0(GFP_KERNEL|__GFP_COMP|__GFP_ZERO), pid 3456, ts 70583523123, free_ts 71218691485
prep_new_page mm/page_alloc.c:2445 [inline]
get_page_from_freelist+0xa72/0x2f80 mm/page_alloc.c:4178
__alloc_pages+0x1b2/0x500 mm/page_alloc.c:5386
alloc_pages+0x18c/0x2a0 mm/mempolicy.c:2272
kmalloc_order+0x34/0xf0 mm/slab_common.c:945
kmalloc_order_trace+0x14/0x120 mm/slab_common.c:961
kmalloc_large include/linux/slab.h:520 [inline]
kmalloc include/linux/slab.h:584 [inline]
kzalloc include/linux/slab.h:721 [inline]
em28xx_usb_probe+0x1f7/0xd00 drivers/media/usb/em28xx/em28xx-cards.c:3855
usb_probe_interface+0x315/0x7f0 drivers/usb/core/driver.c:396
really_probe+0x291/0xf60 drivers/base/dd.c:576
driver_probe_device+0x298/0x410 drivers/base/dd.c:763
__device_attach_driver+0x203/0x2c0 drivers/base/dd.c:870
bus_for_each_drv+0x15f/0x1e0 drivers/base/bus.c:431
__device_attach+0x228/0x4a0 drivers/base/dd.c:938
bus_probe_device+0x1e4/0x290 drivers/base/bus.c:491
device_add+0xbe0/0x2100 drivers/base/core.c:3324
usb_set_configuration+0x113f/0x1910 drivers/usb/core/message.c:2164
usb_generic_driver_probe+0xba/0x100 drivers/usb/core/generic.c:238
page last free stack trace:
reset_page_owner include/linux/page_owner.h:24 [inline]
free_pages_prepare mm/page_alloc.c:1355 [inline]
free_pcp_prepare+0x2c5/0x780 mm/page_alloc.c:1406
free_unref_page_prepare mm/page_alloc.c:3341 [inline]
free_unref_page+0x19/0x690 mm/page_alloc.c:3420
__refcount_sub_and_test include/linux/refcount.h:282 [inline]
__refcount_dec_and_test include/linux/refcount.h:315 [inline]
refcount_dec_and_test include/linux/refcount.h:333 [inline]
kref_put.constprop.0.isra.0+0x3d/0x7e include/linux/kref.h:64
em28xx_ir_fini.cold+0x7c/0x120 drivers/media/usb/em28xx/em28xx-input.c:875
em28xx_close_extension+0xc9/0x2a0 drivers/media/usb/em28xx/em28xx-core.c:1143
em28xx_usb_disconnect.cold+0x14b/0x237 drivers/media/usb/em28xx/em28xx-cards.c:4140
usb_unbind_interface+0x1d8/0x8d0 drivers/usb/core/driver.c:458
__device_release_driver+0x3bd/0x6f0 drivers/base/dd.c:1181
device_release_driver_internal drivers/base/dd.c:1212 [inline]
device_release_driver+0x26/0x40 drivers/base/dd.c:1235
bus_remove_device+0x2eb/0x5a0 drivers/base/bus.c:533
device_del+0x502/0xd40 drivers/base/core.c:3512
usb_disable_device+0x35b/0x7b0 drivers/usb/core/message.c:1413
usb_disconnect.cold+0x27a/0x78e drivers/usb/core/hub.c:2221
hub_port_connect drivers/usb/core/hub.c:5129 [inline]
hub_port_connect_change drivers/usb/core/hub.c:5418 [inline]
port_event drivers/usb/core/hub.c:5564 [inline]
hub_event+0x1c9c/0x4330 drivers/usb/core/hub.c:5646
process_one_work+0x98d/0x1630 kernel/workqueue.c:2276
process_scheduled_works kernel/workqueue.c:2338 [inline]
worker_thread+0x85c/0x11f0 kernel/workqueue.c:2424

Memory state around the buggy address:
ffff888021aa8100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ffff888021aa8180: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff888021aa8200: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
^
ffff888021aa8280: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ffff888021aa8300: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================


---
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