================================================================== 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+0xcb/0x430 drivers/media/v4l2-core/v4l2-fh.c:63 Read of size 8 at addr ffff8880745093d0 by task v4l_id/6445 CPU: 0 UID: 0 PID: 6445 Comm: v4l_id Not tainted 6.11.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024 Call Trace: __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 v4l2_fh_init drivers/media/v4l2-core/v4l2-fh.c:25 [inline] v4l2_fh_open+0xcb/0x430 drivers/media/v4l2-core/v4l2-fh.c:63 em28xx_v4l2_open+0x14c/0x9d0 drivers/media/usb/em28xx/em28xx-video.c:2155 v4l2_open+0x232/0x370 drivers/media/v4l2-core/v4l2-dev.c:427 chrdev_open+0x5b0/0x630 fs/char_dev.c:414 do_dentry_open+0x971/0x1450 fs/open.c:959 vfs_open+0x3e/0x330 fs/open.c:1089 do_open fs/namei.c:3727 [inline] path_openat+0x2b3a/0x3470 fs/namei.c:3886 do_filp_open+0x235/0x490 fs/namei.c:3913 do_sys_openat2+0x13e/0x1d0 fs/open.c:1416 do_sys_open fs/open.c:1431 [inline] __do_sys_openat fs/open.c:1447 [inline] __se_sys_openat fs/open.c:1442 [inline] __x64_sys_openat+0x247/0x2a0 fs/open.c:1442 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0x82/0x160 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x76/0x7e RIP: 0033:0x7f03b51169a4 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:00007ffcd2c5fdf0 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007ffcd2c60008 RCX: 00007f03b51169a4 RDX: 0000000000000000 RSI: 00007ffcd2c60f20 RDI: 00000000ffffff9c RBP: 00007ffcd2c60f20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffcd2c60020 R14: 000055e604ded670 R15: 00007f03b56fba80 Allocated by task 6240: 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+0x7d/0x90 mm/kasan/common.c:387 kasan_kmalloc include/linux/kasan.h:211 [inline] __kmalloc_cache_noprof+0x197/0x280 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/0x1810 kernel/workqueue.c:3312 worker_thread+0xa60/0xfc0 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 6240: 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+0x12/0x30 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+0x12a/0x330 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/0x1810 kernel/workqueue.c:3312 worker_thread+0xa60/0xfc0 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 ffff888074508000 which belongs to the cache kmalloc-8k of size 8192 The buggy address is located 5072 bytes inside of freed 8192-byte region [ffff888074508000, ffff88807450a000) The buggy address belongs to the physical page: page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x74508 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 anon flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff) page_type: 0xfdffffff(slab) raw: 00fff00000000040 ffff888014c42280 0000000000000000 0000000000000001 raw: 0000000000000000 0000000000020002 00000001fdffffff 0000000000000000 head: 00fff00000000040 ffff888014c42280 0000000000000000 0000000000000001 head: 0000000000000000 0000000000020002 00000001fdffffff 0000000000000000 head: 00fff00000000003 ffffea0001d14201 ffffffffffffffff 0000000000000000 head: 0000000700000008 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 0x1d20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 5793, tgid 5793 (syz-executor), ts 102755247682, free_ts 101890641273 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1ee/0x220 mm/page_alloc.c:1493 prep_new_page mm/page_alloc.c:1501 [inline] get_page_from_freelist+0x2e12/0x2ed0 mm/page_alloc.c:3442 __alloc_pages_noprof+0x256/0x6b0 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/0x2e0 mm/slub.c:2484 new_slab mm/slub.c:2537 [inline] ___slab_alloc+0xcd8/0x14b0 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+0x255/0x3d0 mm/slub.c:4170 kmalloc_noprof include/linux/slab.h:685 [inline] kzalloc_noprof include/linux/slab.h:807 [inline] ops_init+0x8b/0x610 net/core/net_namespace.c:129 setup_net+0x3ac/0xad0 net/core/net_namespace.c:343 copy_net_ns+0x39b/0x5d0 net/core/net_namespace.c:508 create_new_namespaces+0x425/0x7b0 kernel/nsproxy.c:110 unshare_nsproxy_namespaces+0x124/0x180 kernel/nsproxy.c:228 ksys_unshare+0x619/0xc10 kernel/fork.c:3309 __do_sys_unshare kernel/fork.c:3380 [inline] __se_sys_unshare kernel/fork.c:3378 [inline] __x64_sys_unshare+0x38/0x40 kernel/fork.c:3378 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0x82/0x160 arch/x86/entry/common.c:83 page last free pid 5758 tgid 5758 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1094 [inline] free_unref_page+0xd0b/0xe70 mm/page_alloc.c:2612 vfree+0x186/0x2e0 mm/vmalloc.c:3364 kcov_put kernel/kcov.c:429 [inline] kcov_close+0x2b/0x50 kernel/kcov.c:525 __fput+0x24a/0x8a0 fs/file_table.c:422 task_work_run+0x24f/0x310 kernel/task_work.c:228 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0xa2f/0x27e0 kernel/exit.c:882 do_group_exit+0x207/0x2c0 kernel/exit.c:1031 get_signal+0x1695/0x1730 kernel/signal.c:2917 arch_do_signal_or_restart+0x96/0x830 arch/x86/kernel/signal.c:310 exit_to_user_mode_loop kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0xc8/0x360 kernel/entry/common.c:218 do_syscall_64+0x8e/0x160 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x76/0x7e Memory state around the buggy address: ffff888074509280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888074509300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888074509380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888074509400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888074509480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================