================================================================== BUG: KASAN: slab-use-after-free in v4l2_fh_init+0x27d/0x2c0 drivers/media/v4l2-core/v4l2-fh.c:25 Read of size 8 at addr ffff888123f34730 by task v4l_id/3335 CPU: 0 PID: 3335 Comm: v4l_id Not tainted 6.3.0-rc6-syzkaller-00128-g8e86652e3e71 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/30/2023 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd9/0x150 lib/dump_stack.c:106 print_address_description.constprop.0+0x2c/0x3c0 mm/kasan/report.c:319 print_report mm/kasan/report.c:430 [inline] kasan_report+0x11c/0x130 mm/kasan/report.c:536 v4l2_fh_init+0x27d/0x2c0 drivers/media/v4l2-core/v4l2-fh.c:25 v4l2_fh_open+0x8c/0xc0 drivers/media/v4l2-core/v4l2-fh.c:63 em28xx_v4l2_open+0x24a/0x7f0 drivers/media/usb/em28xx/em28xx-video.c:2153 v4l2_open+0x220/0x480 drivers/media/v4l2-core/v4l2-dev.c:427 chrdev_open+0x26a/0x770 fs/char_dev.c:414 do_dentry_open+0x6c7/0x12a0 fs/open.c:920 do_open fs/namei.c:3560 [inline] path_openat+0x1baa/0x2750 fs/namei.c:3715 do_filp_open+0x1ba/0x410 fs/namei.c:3742 do_sys_openat2+0x16d/0x4c0 fs/open.c:1348 do_sys_open fs/open.c:1364 [inline] __do_sys_openat fs/open.c:1380 [inline] __se_sys_openat fs/open.c:1375 [inline] __x64_sys_openat+0x143/0x1f0 fs/open.c:1375 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7fa1285b0697 Code: 25 00 00 41 00 3d 00 00 41 00 74 37 64 8b 04 25 18 00 00 00 85 c0 75 5b 44 89 e2 48 89 ee bf 9c ff ff ff b8 01 01 00 00 0f 05 <48> 3d 00 f0 ff ff 0f 87 85 00 00 00 48 83 c4 68 5d 41 5c c3 0f 1f RSP: 002b:00007ffec6eed730 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 0000560ec587cc40 RCX: 00007fa1285b0697 RDX: 0000000000000000 RSI: 00007ffec6eedf24 RDI: 00000000ffffff9c RBP: 00007ffec6eedf24 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 Allocated by task 701: kasan_save_stack+0x22/0x40 mm/kasan/common.c:45 kasan_set_track+0x25/0x30 mm/kasan/common.c:52 ____kasan_kmalloc mm/kasan/common.c:374 [inline] __kasan_kmalloc+0x7b/0x90 mm/kasan/common.c:383 kmalloc include/linux/slab.h:580 [inline] kzalloc include/linux/slab.h:720 [inline] em28xx_v4l2_init drivers/media/usb/em28xx/em28xx-video.c:2532 [inline] em28xx_v4l2_init+0x128/0x3ea0 drivers/media/usb/em28xx/em28xx-video.c:2510 em28xx_init_extension+0x133/0x1f0 drivers/media/usb/em28xx/em28xx-core.c:1116 request_module_async+0x61/0x70 drivers/media/usb/em28xx/em28xx-cards.c:3405 process_one_work+0x991/0x15c0 kernel/workqueue.c:2390 worker_thread+0x669/0x1090 kernel/workqueue.c:2537 kthread+0x2ee/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 Freed by task 701: kasan_save_stack+0x22/0x40 mm/kasan/common.c:45 kasan_set_track+0x25/0x30 mm/kasan/common.c:52 kasan_save_free_info+0x2e/0x40 mm/kasan/generic.c:521 ____kasan_slab_free mm/kasan/common.c:236 [inline] ____kasan_slab_free+0x144/0x1b0 mm/kasan/common.c:200 kasan_slab_free include/linux/kasan.h:162 [inline] slab_free_hook mm/slub.c:1781 [inline] slab_free_freelist_hook mm/slub.c:1807 [inline] slab_free mm/slub.c:3787 [inline] __kmem_cache_free+0x99/0x320 mm/slub.c:3800 em28xx_free_v4l2 drivers/media/usb/em28xx/em28xx-video.c:2118 [inline] kref_put include/linux/kref.h:65 [inline] em28xx_v4l2_init drivers/media/usb/em28xx/em28xx-video.c:2901 [inline] em28xx_v4l2_init+0xd5e/0x3ea0 drivers/media/usb/em28xx/em28xx-video.c:2510 em28xx_init_extension+0x133/0x1f0 drivers/media/usb/em28xx/em28xx-core.c:1116 request_module_async+0x61/0x70 drivers/media/usb/em28xx/em28xx-cards.c:3405 process_one_work+0x991/0x15c0 kernel/workqueue.c:2390 worker_thread+0x669/0x1090 kernel/workqueue.c:2537 kthread+0x2ee/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 The buggy address belongs to the object at ffff888123f34000 which belongs to the cache kmalloc-8k of size 8192 The buggy address is located 1840 bytes inside of freed 8192-byte region [ffff888123f34000, ffff888123f36000) The buggy address belongs to the physical page: page:ffffea00048fcc00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x123f30 head:ffffea00048fcc00 order:3 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0x200000000010200(slab|head|node=0|zone=2) raw: 0200000000010200 ffff888100042280 ffffea00046a2000 0000000000000004 raw: 0000000000000000 0000000080020002 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 0x1d20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 701, tgid 701 (kworker/1:2), ts 107915152569, free_ts 107891654321 prep_new_page mm/page_alloc.c:2553 [inline] get_page_from_freelist+0x15c1/0x2d00 mm/page_alloc.c:4326 __alloc_pages+0x1cb/0x4a0 mm/page_alloc.c:5592 alloc_pages+0x1aa/0x270 mm/mempolicy.c:2283 alloc_slab_page mm/slub.c:1851 [inline] allocate_slab+0x25f/0x390 mm/slub.c:1998 new_slab mm/slub.c:2051 [inline] ___slab_alloc+0xa91/0x1400 mm/slub.c:3193 __slab_alloc.constprop.0+0x56/0xa0 mm/slub.c:3292 __slab_alloc_node mm/slub.c:3345 [inline] slab_alloc_node mm/slub.c:3442 [inline] __kmem_cache_alloc_node+0x291/0x2d0 mm/slub.c:3491 kmalloc_trace+0x26/0xe0 mm/slab_common.c:1061 kmalloc include/linux/slab.h:580 [inline] kzalloc include/linux/slab.h:720 [inline] em28xx_v4l2_init drivers/media/usb/em28xx/em28xx-video.c:2532 [inline] em28xx_v4l2_init+0x128/0x3ea0 drivers/media/usb/em28xx/em28xx-video.c:2510 em28xx_init_extension+0x133/0x1f0 drivers/media/usb/em28xx/em28xx-core.c:1116 request_module_async+0x61/0x70 drivers/media/usb/em28xx/em28xx-cards.c:3405 process_one_work+0x991/0x15c0 kernel/workqueue.c:2390 process_scheduled_works kernel/workqueue.c:2453 [inline] worker_thread+0x807/0x1090 kernel/workqueue.c:2542 kthread+0x2ee/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1454 [inline] free_pcp_prepare+0x5b5/0xa20 mm/page_alloc.c:1504 free_unref_page_prepare mm/page_alloc.c:3388 [inline] free_unref_page+0x1d/0x3c0 mm/page_alloc.c:3483 __unfreeze_partials+0x17c/0x1a0 mm/slub.c:2637 qlink_free mm/kasan/quarantine.c:168 [inline] qlist_free_all+0x6a/0x170 mm/kasan/quarantine.c:187 kasan_quarantine_reduce+0x192/0x220 mm/kasan/quarantine.c:294 __kasan_slab_alloc+0x45/0x60 mm/kasan/common.c:305 kasan_slab_alloc include/linux/kasan.h:186 [inline] slab_post_alloc_hook mm/slab.h:769 [inline] slab_alloc_node mm/slub.c:3452 [inline] slab_alloc mm/slub.c:3460 [inline] __kmem_cache_alloc_lru mm/slub.c:3467 [inline] kmem_cache_alloc_lru+0x205/0x5c0 mm/slub.c:3483 alloc_inode_sb include/linux/fs.h:2686 [inline] shmem_alloc_inode+0x27/0x50 mm/shmem.c:3874 alloc_inode+0x61/0x230 fs/inode.c:260 new_inode_pseudo fs/inode.c:1019 [inline] new_inode+0x2b/0x280 fs/inode.c:1047 shmem_get_inode+0x1a1/0xe60 mm/shmem.c:2359 shmem_mknod+0x66/0x220 mm/shmem.c:2930 lookup_open.isra.0+0x105a/0x1400 fs/namei.c:3416 open_last_lookups fs/namei.c:3484 [inline] path_openat+0x975/0x2750 fs/namei.c:3712 do_filp_open+0x1ba/0x410 fs/namei.c:3742 do_sys_openat2+0x16d/0x4c0 fs/open.c:1348 Memory state around the buggy address: ffff888123f34600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888123f34680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888123f34700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888123f34780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888123f34800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================