[syzbot] [media?] KASAN: slab-use-after-free Read in em28xx_release_resources

syzbot
2024-08-02T07:49:19Z

Hello,

syzbot found the following issue on:

HEAD commit: 6342649c33d2 Merge tag 'block-6.11-20240726' of git://git...
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=159feda1980000
kernel config: https://syzkaller.appspot.com/x/.config?x=5efb917b1462a973
dashboard link: https://syzkaller.appspot.com/bug?extid=16062f26c6480975e5ed
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
userspace arch: i386

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/f7155d1516ca/disk-6342649c.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/f724a979b927/vmlinux-6342649c.xz
kernel image: https://storage.googleapis.com/syzbot-assets/480121fc37f0/bzImage-6342649c.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+16062f26c6480975e5ed@syzkaller.appspotmail.com

em28xx 5-1:0.0: Closing input extension
==================================================================
BUG: KASAN: slab-use-after-free in media_device_unregister+0x154/0x470
Read of size 8 at addr ffff888058df4210 by task kworker/0:1/9

CPU: 0 UID: 0 PID: 9 Comm: kworker/0:1 Not tainted 6.10.0-syzkaller-12881-g6342649c33d2 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024
Workqueue: usb_hub_wq hub_event
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:93 [inline]
dump_stack_lvl+0x241/0x360 lib/dump_stack.c:119
print_address_description mm/kasan/report.c:377 [inline]
print_report+0x169/0x550 mm/kasan/report.c:488
kasan_report+0x143/0x180 mm/kasan/report.c:601
media_device_unregister+0x154/0x470
em28xx_unregister_media_device drivers/media/usb/em28xx/em28xx-cards.c:3511 [inline]
em28xx_release_resources+0xa7/0x230 drivers/media/usb/em28xx/em28xx-cards.c:3532
em28xx_usb_disconnect+0x1cc/0x530 drivers/media/usb/em28xx/em28xx-cards.c:4201
usb_unbind_interface+0x25e/0x940 drivers/usb/core/driver.c:461
device_remove drivers/base/dd.c:568 [inline]
__device_release_driver drivers/base/dd.c:1272 [inline]
device_release_driver_internal+0x503/0x7c0 drivers/base/dd.c:1295
bus_remove_device+0x34f/0x420 drivers/base/bus.c:574
device_del+0x57a/0x9b0 drivers/base/core.c:3868
usb_disable_device+0x3bf/0x850 drivers/usb/core/message.c:1418
usb_disconnect+0x340/0x950 drivers/usb/core/hub.c:2304
hub_port_connect drivers/usb/core/hub.c:5361 [inline]
hub_port_connect_change drivers/usb/core/hub.c:5661 [inline]
port_event drivers/usb/core/hub.c:5821 [inline]
hub_event+0x1eb9/0x5150 drivers/usb/core/hub.c:5903
process_one_work kernel/workqueue.c:3231 [inline]
process_scheduled_works+0xa2c/0x1830 kernel/workqueue.c:3312
worker_thread+0x86d/0xd40 kernel/workqueue.c:3390
kthread+0x2f0/0x390 kernel/kthread.c:389
ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
</TASK>

Allocated by task 31851:
kasan_save_stack mm/kasan/common.c:47 [inline]
kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
poison_kmalloc_redzone mm/kasan/common.c:370 [inline]
__kasan_kmalloc+0x98/0xb0 mm/kasan/common.c:387
kasan_kmalloc include/linux/kasan.h:211 [inline]
__kmalloc_cache_noprof+0x19c/0x2c0 mm/slub.c:4189
kmalloc_noprof include/linux/slab.h:681 [inline]
kzalloc_noprof include/linux/slab.h:807 [inline]
em28xx_v4l2_init+0xfd/0x2f40 drivers/media/usb/em28xx/em28xx-video.c:2534
em28xx_init_extension+0x120/0x1c0 drivers/media/usb/em28xx/em28xx-core.c:1117
process_one_work kernel/workqueue.c:3231 [inline]
process_scheduled_works+0xa2c/0x1830 kernel/workqueue.c:3312
worker_thread+0x86d/0xd40 kernel/workqueue.c:3390
kthread+0x2f0/0x390 kernel/kthread.c:389
ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

Freed by task 31851:
kasan_save_stack mm/kasan/common.c:47 [inline]
kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:579
poison_slab_object+0xe0/0x150 mm/kasan/common.c:240
__kasan_slab_free+0x37/0x60 mm/kasan/common.c:256
kasan_slab_free include/linux/kasan.h:184 [inline]
slab_free_hook mm/slub.c:2252 [inline]
slab_free mm/slub.c:4473 [inline]
kfree+0x149/0x360 mm/slub.c:4594
em28xx_free_v4l2 drivers/media/usb/em28xx/em28xx-video.c:2120 [inline]
kref_put include/linux/kref.h:65 [inline]
em28xx_v4l2_init+0x16d7/0x2f40 drivers/media/usb/em28xx/em28xx-video.c:2903
em28xx_init_extension+0x120/0x1c0 drivers/media/usb/em28xx/em28xx-core.c:1117
process_one_work kernel/workqueue.c:3231 [inline]
process_scheduled_works+0xa2c/0x1830 kernel/workqueue.c:3312
worker_thread+0x86d/0xd40 kernel/workqueue.c:3390
kthread+0x2f0/0x390 kernel/kthread.c:389
ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

The buggy address belongs to the object at ffff888058df4000
which belongs to the cache kmalloc-8k of size 8192
The buggy address is located 528 bytes inside of
freed 8192-byte region [ffff888058df4000, ffff888058df6000)

The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x58df0
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff)
page_type: 0xfdffffff(slab)
raw: 00fff00000000040 ffff888015842280 dead000000000122 0000000000000000
raw: 0000000000000000 0000000080020002 00000001fdffffff 0000000000000000
head: 00fff00000000040 ffff888015842280 dead000000000122 0000000000000000
head: 0000000000000000 0000000080020002 00000001fdffffff 0000000000000000
head: 00fff00000000003 ffffea0001637c01 ffffffffffffffff 0000000000000000
head: 0000000000000008 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Unmovable, gfp_mask 0x152820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_HARDWALL), pid 3922, tgid 3922 (kworker/u8:8), ts 2368883364470, free_ts 2368880799693
set_page_owner include/linux/page_owner.h:32 [inline]
post_alloc_hook+0x1f3/0x230 mm/page_alloc.c:1493
prep_new_page mm/page_alloc.c:1501 [inline]
get_page_from_freelist+0x2e4c/0x2f10 mm/page_alloc.c:3442
__alloc_pages_noprof+0x256/0x6c0 mm/page_alloc.c:4700
__alloc_pages_node_noprof include/linux/gfp.h:269 [inline]
alloc_pages_node_noprof include/linux/gfp.h:296 [inline]
alloc_slab_page+0x5f/0x120 mm/slub.c:2321
allocate_slab+0x5a/0x2f0 mm/slub.c:2484
new_slab mm/slub.c:2537 [inline]
___slab_alloc+0xcd1/0x14b0 mm/slub.c:3723
__slab_alloc+0x58/0xa0 mm/slub.c:3813
__slab_alloc_node mm/slub.c:3866 [inline]
slab_alloc_node mm/slub.c:4025 [inline]
__do_kmalloc_node mm/slub.c:4157 [inline]
__kmalloc_noprof+0x25a/0x400 mm/slub.c:4170
kmalloc_noprof include/linux/slab.h:685 [inline]
n_hdlc_tty_receive+0x1ce/0x4e0 drivers/tty/n_hdlc.c:393
tty_ldisc_receive_buf+0x11f/0x170 drivers/tty/tty_buffer.c:391
tty_port_default_receive_buf+0x6d/0xa0 drivers/tty/tty_port.c:37
receive_buf drivers/tty/tty_buffer.c:445 [inline]
flush_to_ldisc+0x328/0x860 drivers/tty/tty_buffer.c:495
process_one_work kernel/workqueue.c:3231 [inline]
process_scheduled_works+0xa2c/0x1830 kernel/workqueue.c:3312
worker_thread+0x86d/0xd40 kernel/workqueue.c:3390
kthread+0x2f0/0x390 kernel/kthread.c:389
ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
page last free pid 13102 tgid 13102 stack trace:
reset_page_owner include/linux/page_owner.h:25 [inline]
free_pages_prepare mm/page_alloc.c:1094 [inline]
free_unref_page+0xd22/0xea0 mm/page_alloc.c:2612
discard_slab mm/slub.c:2583 [inline]
__put_partials+0xeb/0x130 mm/slub.c:3051
put_cpu_partial+0x17c/0x250 mm/slub.c:3126
__slab_free+0x2ea/0x3d0 mm/slub.c:4343
qlink_free mm/kasan/quarantine.c:163 [inline]
qlist_free_all+0x9e/0x140 mm/kasan/quarantine.c:179
kasan_quarantine_reduce+0x14f/0x170 mm/kasan/quarantine.c:286
__kasan_slab_alloc+0x23/0x80 mm/kasan/common.c:322
kasan_slab_alloc include/linux/kasan.h:201 [inline]
slab_post_alloc_hook mm/slub.c:3988 [inline]
slab_alloc_node mm/slub.c:4037 [inline]
kmem_cache_alloc_noprof+0x135/0x2a0 mm/slub.c:4044
anon_vma_chain_alloc mm/rmap.c:142 [inline]
__anon_vma_prepare+0xc4/0x4a0 mm/rmap.c:195
vmf_anon_prepare mm/memory.c:3289 [inline]
do_anonymous_page mm/memory.c:4551 [inline]
do_pte_missing mm/memory.c:3945 [inline]
handle_pte_fault+0x5788/0x6eb0 mm/memory.c:5522
__handle_mm_fault mm/memory.c:5665 [inline]
handle_mm_fault+0x1029/0x1980 mm/memory.c:5833
do_user_addr_fault arch/x86/mm/fault.c:1338 [inline]
handle_page_fault arch/x86/mm/fault.c:1481 [inline]
exc_page_fault+0x459/0x8c0 arch/x86/mm/fault.c:1539
asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623

Memory state around the buggy address:
ffff888058df4100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff888058df4180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888058df4200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff888058df4280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff888058df4300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================

---
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