================================================================== BUG: KASAN: slab-use-after-free in v4l2_fh_init drivers/media/v4l2-core/v4l2-fh.c:25 [inline] BUG: KASAN: slab-use-after-free in v4l2_fh_open+0xc8/0x430 drivers/media/v4l2-core/v4l2-fh.c:63 Read of size 8 at addr ffff88805dcb4738 by task v4l_id/11867 CPU: 0 UID: 0 PID: 11867 Comm: v4l_id Not tainted 6.12.0-next-20241122-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/30/2024 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0x169/0x550 mm/kasan/report.c:489 kasan_report+0x143/0x180 mm/kasan/report.c:602 v4l2_fh_init drivers/media/v4l2-core/v4l2-fh.c:25 [inline] v4l2_fh_open+0xc8/0x430 drivers/media/v4l2-core/v4l2-fh.c:63 em28xx_v4l2_open+0x14c/0x9d0 drivers/media/usb/em28xx/em28xx-video.c:2153 v4l2_open+0x22f/0x370 drivers/media/v4l2-core/v4l2-dev.c:429 chrdev_open+0x521/0x600 fs/char_dev.c:414 do_dentry_open+0xbe1/0x1b70 fs/open.c:945 vfs_open+0x3e/0x330 fs/open.c:1075 do_open fs/namei.c:3828 [inline] path_openat+0x2c84/0x3590 fs/namei.c:3987 do_filp_open+0x27f/0x4e0 fs/namei.c:4014 do_sys_openat2+0x13e/0x1d0 fs/open.c:1402 do_sys_open fs/open.c:1417 [inline] __do_sys_openat fs/open.c:1433 [inline] __se_sys_openat fs/open.c:1428 [inline] __x64_sys_openat+0x247/0x2a0 fs/open.c:1428 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f6ac0d169a4 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:00007ffe8efe9740 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007ffe8efe9958 RCX: 00007f6ac0d169a4 RDX: 0000000000000000 RSI: 00007ffe8efe9f1e RDI: 00000000ffffff9c RBP: 00007ffe8efe9f1e R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffe8efe9970 R14: 0000556d8c2e0670 R15: 00007f6ac11b1a80 Allocated by task 10313: 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:377 [inline] __kasan_kmalloc+0x98/0xb0 mm/kasan/common.c:394 kasan_kmalloc include/linux/kasan.h:260 [inline] __kmalloc_cache_noprof+0x243/0x390 mm/slub.c:4314 kmalloc_noprof include/linux/slab.h:901 [inline] kzalloc_noprof include/linux/slab.h:1037 [inline] em28xx_v4l2_init+0xfd/0x2f40 drivers/media/usb/em28xx/em28xx-video.c:2532 em28xx_init_extension+0x120/0x1c0 drivers/media/usb/em28xx/em28xx-core.c:1117 process_one_work kernel/workqueue.c:3229 [inline] process_scheduled_works+0xa63/0x1850 kernel/workqueue.c:3310 worker_thread+0x870/0xd30 kernel/workqueue.c:3391 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 10313: 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:582 poison_slab_object mm/kasan/common.c:247 [inline] __kasan_slab_free+0x59/0x70 mm/kasan/common.c:264 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2338 [inline] slab_free mm/slub.c:4598 [inline] kfree+0x196/0x420 mm/slub.c:4746 em28xx_free_v4l2 drivers/media/usb/em28xx/em28xx-video.c:2118 [inline] kref_put include/linux/kref.h:65 [inline] em28xx_v4l2_init+0x16d7/0x2f40 drivers/media/usb/em28xx/em28xx-video.c:2901 em28xx_init_extension+0x120/0x1c0 drivers/media/usb/em28xx/em28xx-core.c:1117 process_one_work kernel/workqueue.c:3229 [inline] process_scheduled_works+0xa63/0x1850 kernel/workqueue.c:3310 worker_thread+0x870/0xd30 kernel/workqueue.c:3391 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 ffff88805dcb4000 which belongs to the cache kmalloc-8k of size 8192 The buggy address is located 1848 bytes inside of freed 8192-byte region [ffff88805dcb4000, ffff88805dcb6000) The buggy address belongs to the physical page: page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x5dcb0 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 ksm flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000040 ffff88801ac42280 ffffea0000c9f600 dead000000000003 raw: 0000000000000000 0000000080020002 00000001f5000000 0000000000000000 head: 00fff00000000040 ffff88801ac42280 ffffea0000c9f600 dead000000000003 head: 0000000000000000 0000000080020002 00000001f5000000 0000000000000000 head: 00fff00000000003 ffffea0001772c01 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 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5824, tgid 5824 (syz-executor), ts 63889560213, free_ts 16658741791 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1f3/0x230 mm/page_alloc.c:1556 prep_new_page mm/page_alloc.c:1564 [inline] get_page_from_freelist+0x3725/0x3870 mm/page_alloc.c:3510 __alloc_pages_noprof+0x292/0x710 mm/page_alloc.c:4787 alloc_pages_mpol_noprof+0x3e8/0x680 mm/mempolicy.c:2265 alloc_slab_page+0x6a/0x140 mm/slub.c:2408 allocate_slab+0x5a/0x2f0 mm/slub.c:2574 new_slab mm/slub.c:2627 [inline] ___slab_alloc+0xcd1/0x14b0 mm/slub.c:3815 __slab_alloc+0x58/0xa0 mm/slub.c:3905 __slab_alloc_node mm/slub.c:3980 [inline] slab_alloc_node mm/slub.c:4141 [inline] __do_kmalloc_node mm/slub.c:4282 [inline] __kmalloc_node_noprof+0x2ee/0x4d0 mm/slub.c:4289 __kvmalloc_node_noprof+0x72/0x190 mm/util.c:650 kvmalloc_array_node_noprof include/linux/slab.h:1063 [inline] __ptr_ring_init_queue_alloc_noprof include/linux/ptr_ring.h:471 [inline] ptr_ring_init_noprof include/linux/ptr_ring.h:489 [inline] skb_array_init_noprof include/linux/skb_array.h:182 [inline] pfifo_fast_init+0x24f/0x6e0 net/sched/sch_generic.c:871 qdisc_create_dflt+0x136/0x4b0 net/sched/sch_generic.c:1021 attach_one_default_qdisc net/sched/sch_generic.c:1180 [inline] netdev_for_each_tx_queue include/linux/netdevice.h:2562 [inline] attach_default_qdiscs net/sched/sch_generic.c:1198 [inline] dev_activate+0x3c0/0x1240 net/sched/sch_generic.c:1257 __dev_open+0x352/0x450 net/core/dev.c:1485 __dev_change_flags+0x1e2/0x6f0 net/core/dev.c:8943 dev_change_flags+0x8b/0x1a0 net/core/dev.c:9015 page last free pid 1 tgid 1 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1127 [inline] free_unref_page+0xdf9/0x1140 mm/page_alloc.c:2693 free_contig_range+0x152/0x550 mm/page_alloc.c:6666 destroy_args+0x92/0x910 mm/debug_vm_pgtable.c:1017 debug_vm_pgtable+0x4be/0x550 mm/debug_vm_pgtable.c:1397 do_one_initcall+0x248/0x880 init/main.c:1266 do_initcall_level+0x157/0x210 init/main.c:1328 do_initcalls+0x3f/0x80 init/main.c:1344 kernel_init_freeable+0x435/0x5d0 init/main.c:1577 kernel_init+0x1d/0x2b0 init/main.c:1466 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Memory state around the buggy address: ffff88805dcb4600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88805dcb4680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88805dcb4700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88805dcb4780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88805dcb4800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb 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