syzbot

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BUG: KASAN: use-after-free in v4l2_fh_init drivers/media/v4l2-core/v4l2-fh.c:25 [inline]
BUG: KASAN: use-after-free in v4l2_fh_open+0xc7/0x430 drivers/media/v4l2-core/v4l2-fh.c:63
Read of size 8 at addr ffff888075014738 by task v4l_id/7889

CPU: 0 PID: 7889 Comm: v4l_id Not tainted 6.1.107-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106
 print_address_description mm/kasan/report.c:284 [inline]
 print_report+0x15f/0x4f0 mm/kasan/report.c:395
 kasan_report+0x136/0x160 mm/kasan/report.c:495
 v4l2_fh_init drivers/media/v4l2-core/v4l2-fh.c:25 [inline]
 v4l2_fh_open+0xc7/0x430 drivers/media/v4l2-core/v4l2-fh.c:63
 em28xx_v4l2_open+0x15d/0xa10 drivers/media/usb/em28xx/em28xx-video.c:2153
 v4l2_open+0x228/0x360 drivers/media/v4l2-core/v4l2-dev.c:427
 chrdev_open+0x54a/0x630 fs/char_dev.c:414
 do_dentry_open+0x7f9/0x10f0 fs/open.c:882
 do_open fs/namei.c:3628 [inline]
 path_openat+0x2644/0x2e60 fs/namei.c:3785
 do_filp_open+0x230/0x480 fs/namei.c:3812
 do_sys_openat2+0x13b/0x4f0 fs/open.c:1318
 do_sys_open fs/open.c:1334 [inline]
 __do_sys_openat fs/open.c:1350 [inline]
 __se_sys_openat fs/open.c:1345 [inline]
 __x64_sys_openat+0x243/0x290 fs/open.c:1345
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fdd21f599a4
Code: 24 20 48 8d 44 24 30 48 89 44 24 28 64 8b 04 25 18 00 00 00 85 c0 75 2c 44 89 e2 48 89 ee bf 9c ff ff ff b8 01 01 00 00 0f 05 <48> 3d 00 f0 ff ff 76 60 48 8b 15 55 a4 0d 00 f7 d8 64 89 02 48 83
RSP: 002b:00007fff527b2be0 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007fff527b2df8 RCX: 00007fdd21f599a4
RDX: 0000000000000000 RSI: 00007fff527b4f1f RDI: 00000000ffffff9c
RBP: 00007fff527b4f1f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fff527b2e10 R14: 0000562d24f59670 R15: 00007fdd22114a80
 </TASK>

Allocated by task 26:
 kasan_save_stack mm/kasan/common.c:45 [inline]
 kasan_set_track+0x4b/0x70 mm/kasan/common.c:52
 ____kasan_kmalloc mm/kasan/common.c:374 [inline]
 __kasan_kmalloc+0x97/0xb0 mm/kasan/common.c:383
 kmalloc include/linux/slab.h:557 [inline]
 kzalloc include/linux/slab.h:693 [inline]
 em28xx_v4l2_init+0x103/0x2db0 drivers/media/usb/em28xx/em28xx-video.c:2532
 em28xx_init_extension+0x11b/0x1c0 drivers/media/usb/em28xx/em28xx-core.c:1116
 process_one_work+0x8a9/0x11d0 kernel/workqueue.c:2292
 process_scheduled_works kernel/workqueue.c:2355 [inline]
 worker_thread+0xcb2/0x1200 kernel/workqueue.c:2444
 kthread+0x28d/0x320 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295

Freed by task 26:
 kasan_save_stack mm/kasan/common.c:45 [inline]
 kasan_set_track+0x4b/0x70 mm/kasan/common.c:52
 kasan_save_free_info+0x27/0x40 mm/kasan/generic.c:516
 ____kasan_slab_free+0xd6/0x120 mm/kasan/common.c:236
 kasan_slab_free include/linux/kasan.h:177 [inline]
 slab_free_hook mm/slub.c:1724 [inline]
 slab_free_freelist_hook mm/slub.c:1750 [inline]
 slab_free mm/slub.c:3661 [inline]
 __kmem_cache_free+0x25c/0x3c0 mm/slub.c:3674
 em28xx_free_v4l2 drivers/media/usb/em28xx/em28xx-video.c:2118 [inline]
 kref_put include/linux/kref.h:65 [inline]
 em28xx_v4l2_init+0x1604/0x2db0 drivers/media/usb/em28xx/em28xx-video.c:2901
 em28xx_init_extension+0x11b/0x1c0 drivers/media/usb/em28xx/em28xx-core.c:1116
 process_one_work+0x8a9/0x11d0 kernel/workqueue.c:2292
 process_scheduled_works kernel/workqueue.c:2355 [inline]
 worker_thread+0xcb2/0x1200 kernel/workqueue.c:2444
 kthread+0x28d/0x320 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295

The buggy address belongs to the object at ffff888075014000
 which belongs to the cache kmalloc-8k of size 8192
The buggy address is located 1848 bytes inside of
 8192-byte region [ffff888075014000, ffff888075016000)

The buggy address belongs to the physical page:
page:ffffea0001d40400 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x75010
head:ffffea0001d40400 order:3 compound_mapcount:0 compound_pincount:0
flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000010200 ffffea00019a0800 dead000000000004 ffff888017c42280
raw: 0000000000000000 0000000000020002 00000001ffffffff 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 0x1d28c0(GFP_NOWAIT|__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 3305, tgid 3305 (dhcpcd), ts 305386813115, free_ts 304568610197
 set_page_owner include/linux/page_owner.h:31 [inline]
 post_alloc_hook+0x18d/0x1b0 mm/page_alloc.c:2517
 prep_new_page mm/page_alloc.c:2524 [inline]
 get_page_from_freelist+0x322e/0x33b0 mm/page_alloc.c:4290
 __alloc_pages+0x28d/0x770 mm/page_alloc.c:5558
 alloc_slab_page+0x6a/0x150 mm/slub.c:1794
 allocate_slab mm/slub.c:1939 [inline]
 new_slab+0x84/0x2d0 mm/slub.c:1992
 ___slab_alloc+0xc20/0x1270 mm/slub.c:3180
 __slab_alloc mm/slub.c:3279 [inline]
 slab_alloc_node mm/slub.c:3364 [inline]
 __kmem_cache_alloc_node+0x19f/0x260 mm/slub.c:3437
 __do_kmalloc_node mm/slab_common.c:935 [inline]
 __kmalloc_node_track_caller+0xa0/0x220 mm/slab_common.c:956
 kmalloc_reserve net/core/skbuff.c:446 [inline]
 __alloc_skb+0x135/0x670 net/core/skbuff.c:515
 alloc_skb include/linux/skbuff.h:1271 [inline]
 netlink_dump+0x1fb/0xca0 net/netlink/af_netlink.c:2199
 __netlink_dump_start+0x521/0x6c0 net/netlink/af_netlink.c:2334
 netlink_dump_start include/linux/netlink.h:269 [inline]
 rtnetlink_rcv_msg+0xd4c/0xff0 net/core/rtnetlink.c:6077
 netlink_rcv_skb+0x1cd/0x410 net/netlink/af_netlink.c:2507
 netlink_unicast_kernel net/netlink/af_netlink.c:1326 [inline]
 netlink_unicast+0x7d8/0x970 net/netlink/af_netlink.c:1352
 netlink_sendmsg+0xa26/0xd60 net/netlink/af_netlink.c:1874
 sock_sendmsg_nosec net/socket.c:718 [inline]
 __sock_sendmsg net/socket.c:730 [inline]
 __sys_sendto+0x480/0x600 net/socket.c:2148
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1444 [inline]
 free_pcp_prepare mm/page_alloc.c:1494 [inline]
 free_unref_page_prepare+0xf63/0x1120 mm/page_alloc.c:3369
 free_unref_page+0x33/0x3e0 mm/page_alloc.c:3464
 free_slab mm/slub.c:2031 [inline]
 discard_slab mm/slub.c:2037 [inline]
 __unfreeze_partials+0x1b7/0x210 mm/slub.c:2586
 put_cpu_partial+0x17b/0x250 mm/slub.c:2662
 qlink_free mm/kasan/quarantine.c:168 [inline]
 qlist_free_all+0x76/0xe0 mm/kasan/quarantine.c:187
 kasan_quarantine_reduce+0x156/0x170 mm/kasan/quarantine.c:294
 __kasan_slab_alloc+0x1f/0x70 mm/kasan/common.c:305
 kasan_slab_alloc include/linux/kasan.h:201 [inline]
 slab_post_alloc_hook+0x52/0x3a0 mm/slab.h:737
 slab_alloc_node mm/slub.c:3398 [inline]
 kmem_cache_alloc_node+0x136/0x310 mm/slub.c:3443
 __alloc_skb+0xde/0x670 net/core/skbuff.c:505
 alloc_skb include/linux/skbuff.h:1271 [inline]
 nlmsg_new include/net/netlink.h:991 [inline]
 rtmsg_ifa+0x1e7/0x3a0 net/ipv4/devinet.c:1920
 __inet_del_ifa+0x867/0x1020 net/ipv4/devinet.c:430
 inet_del_ifa net/ipv4/devinet.c:468 [inline]
 inetdev_destroy net/ipv4/devinet.c:321 [inline]
 inetdev_event+0x62b/0x1490 net/ipv4/devinet.c:1602
 notifier_call_chain kernel/notifier.c:87 [inline]
 raw_notifier_call_chain+0xd0/0x170 kernel/notifier.c:455
 call_netdevice_notifiers_info net/core/dev.c:1970 [inline]
 call_netdevice_notifiers_extack net/core/dev.c:2008 [inline]
 call_netdevice_notifiers net/core/dev.c:2022 [inline]
 unregister_netdevice_many+0xebf/0x17a0 net/core/dev.c:10882
 default_device_exit_batch+0x956/0x9d0 net/core/dev.c:11395

Memory state around the buggy address:
 ffff888075014600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888075014680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888075014700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                        ^
 ffff888075014780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888075014800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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