================================================================== 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 ffff88801b0fc740 by task v4l_id/5558 CPU: 0 PID: 5558 Comm: v4l_id Not tainted 6.10.0-rc6-syzkaller-00212-g1dd28064d416 #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:114 print_address_description mm/kasan/report.c:377 [inline] print_report+0xc3/0x620 mm/kasan/report.c:488 kasan_report+0xd9/0x110 mm/kasan/report.c:601 v4l2_fh_init+0x27d/0x2c0 drivers/media/v4l2-core/v4l2-fh.c:25 v4l2_fh_open+0x89/0xc0 drivers/media/v4l2-core/v4l2-fh.c:63 em28xx_v4l2_open+0x250/0x7e0 drivers/media/usb/em28xx/em28xx-video.c:2155 v4l2_open+0x228/0x490 drivers/media/v4l2-core/v4l2-dev.c:427 chrdev_open+0x26d/0x6f0 fs/char_dev.c:414 do_dentry_open+0x91f/0x15f0 fs/open.c:955 vfs_open+0x82/0x3f0 fs/open.c:1086 do_open fs/namei.c:3654 [inline] path_openat+0x21fc/0x2e50 fs/namei.c:3813 do_filp_open+0x1dc/0x430 fs/namei.c:3840 do_sys_openat2+0x17a/0x1e0 fs/open.c:1413 do_sys_open fs/open.c:1428 [inline] __do_sys_openat fs/open.c:1444 [inline] __se_sys_openat fs/open.c:1439 [inline] __x64_sys_openat+0x175/0x210 fs/open.c:1439 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fb186f169a4 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:00007fffef1ede70 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007fffef1ee088 RCX: 00007fb186f169a4 RDX: 0000000000000000 RSI: 00007fffef1eef21 RDI: 00000000ffffff9c RBP: 00007fffef1eef21 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fffef1ee0a0 R14: 00005567426e2670 R15: 00007fb18747ea80 Allocated by task 5474: kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:370 [inline] __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:387 kmalloc_noprof include/linux/slab.h:660 [inline] kzalloc_noprof include/linux/slab.h:778 [inline] em28xx_v4l2_init+0x114/0x4070 drivers/media/usb/em28xx/em28xx-video.c:2534 em28xx_init_extension+0x137/0x200 drivers/media/usb/em28xx/em28xx-core.c:1116 request_module_async+0x61/0x70 drivers/media/usb/em28xx/em28xx-cards.c:3405 process_one_work+0x9c5/0x1b40 kernel/workqueue.c:3248 process_scheduled_works kernel/workqueue.c:3329 [inline] worker_thread+0x6c8/0xf30 kernel/workqueue.c:3409 kthread+0x2c1/0x3a0 kernel/kthread.c:389 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Freed by task 5474: kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:579 poison_slab_object+0xf7/0x160 mm/kasan/common.c:240 __kasan_slab_free+0x32/0x50 mm/kasan/common.c:256 kasan_slab_free include/linux/kasan.h:184 [inline] slab_free_hook mm/slub.c:2196 [inline] slab_free mm/slub.c:4438 [inline] kfree+0x12a/0x3b0 mm/slub.c:4559 em28xx_free_v4l2 drivers/media/usb/em28xx/em28xx-video.c:2120 [inline] kref_put include/linux/kref.h:65 [inline] em28xx_v4l2_init+0x22a9/0x4070 drivers/media/usb/em28xx/em28xx-video.c:2903 em28xx_init_extension+0x137/0x200 drivers/media/usb/em28xx/em28xx-core.c:1116 request_module_async+0x61/0x70 drivers/media/usb/em28xx/em28xx-cards.c:3405 process_one_work+0x9c5/0x1b40 kernel/workqueue.c:3248 process_scheduled_works kernel/workqueue.c:3329 [inline] worker_thread+0x6c8/0xf30 kernel/workqueue.c:3409 kthread+0x2c1/0x3a0 kernel/kthread.c:389 ret_from_fork+0x45/0x80 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 ffff88801b0fc000 which belongs to the cache kmalloc-8k of size 8192 The buggy address is located 1856 bytes inside of freed 8192-byte region [ffff88801b0fc000, ffff88801b0fe000) The buggy address belongs to the physical page: page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1b0f8 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: 0xffffefff(slab) raw: 00fff00000000040 ffff888015443180 ffffea00007b4e00 dead000000000002 raw: 0000000000000000 0000000080020002 00000001ffffefff 0000000000000000 head: 00fff00000000040 ffff888015443180 ffffea00007b4e00 dead000000000002 head: 0000000000000000 0000000080020002 00000001ffffefff 0000000000000000 head: 00fff00000000003 ffffea00006c3e01 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 1, tgid 1 (swapper/0), ts 23461290733, free_ts 23429758118 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x2d1/0x350 mm/page_alloc.c:1473 prep_new_page mm/page_alloc.c:1481 [inline] get_page_from_freelist+0x1353/0x2e50 mm/page_alloc.c:3425 __alloc_pages_noprof+0x22b/0x2460 mm/page_alloc.c:4683 __alloc_pages_node_noprof include/linux/gfp.h:269 [inline] alloc_pages_node_noprof include/linux/gfp.h:296 [inline] alloc_slab_page+0x56/0x110 mm/slub.c:2265 allocate_slab mm/slub.c:2428 [inline] new_slab+0x84/0x260 mm/slub.c:2481 ___slab_alloc+0xdac/0x1870 mm/slub.c:3667 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3757 __slab_alloc_node mm/slub.c:3810 [inline] slab_alloc_node mm/slub.c:3990 [inline] __do_kmalloc_node mm/slub.c:4122 [inline] __kmalloc_noprof+0x36d/0x410 mm/slub.c:4136 kmalloc_noprof include/linux/slab.h:664 [inline] kmalloc_array_noprof include/linux/slab.h:699 [inline] cache_create_net+0xa0/0x220 net/sunrpc/cache.c:1749 rsc_cache_create_net net/sunrpc/auth_gss/svcauth_gss.c:2052 [inline] gss_svc_init_net+0x69/0x660 net/sunrpc/auth_gss/svcauth_gss.c:2080 ops_init+0xb9/0x650 net/core/net_namespace.c:139 __register_pernet_operations net/core/net_namespace.c:1252 [inline] register_pernet_operations+0x349/0x6b0 net/core/net_namespace.c:1325 register_pernet_subsys+0x28/0x40 net/core/net_namespace.c:1366 init_rpcsec_gss+0x5c/0xc0 net/sunrpc/auth_gss/auth_gss.c:2263 do_one_initcall+0x128/0x700 init/main.c:1267 do_initcall_level init/main.c:1329 [inline] do_initcalls init/main.c:1345 [inline] do_basic_setup init/main.c:1364 [inline] kernel_init_freeable+0x69d/0xca0 init/main.c:1578 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:1093 [inline] free_unref_page+0x64a/0xe40 mm/page_alloc.c:2588 __put_partials+0x14c/0x170 mm/slub.c:2995 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x4e/0x140 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x192/0x1e0 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:322 kasan_slab_alloc include/linux/kasan.h:201 [inline] slab_post_alloc_hook mm/slub.c:3940 [inline] slab_alloc_node mm/slub.c:4002 [inline] kmem_cache_alloc_lru_noprof+0x121/0x2f0 mm/slub.c:4021 __d_alloc+0x31/0xaa0 fs/dcache.c:1624 d_alloc+0x4a/0x1e0 fs/dcache.c:1704 d_alloc_parallel+0xe9/0x12b0 fs/dcache.c:2462 __lookup_slow+0x194/0x460 fs/namei.c:1677 lookup_one_len+0x181/0x1b0 fs/namei.c:2764 start_creating.part.0+0x12f/0x3a0 fs/debugfs/inode.c:378 start_creating fs/debugfs/inode.c:351 [inline] __debugfs_create_file+0xa5/0x660 fs/debugfs/inode.c:423 rfcomm_init+0x11a/0x190 net/bluetooth/rfcomm/core.c:2238 do_one_initcall+0x128/0x700 init/main.c:1267 do_initcall_level init/main.c:1329 [inline] do_initcalls init/main.c:1345 [inline] do_basic_setup init/main.c:1364 [inline] kernel_init_freeable+0x69d/0xca0 init/main.c:1578 Memory state around the buggy address: ffff88801b0fc600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88801b0fc680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88801b0fc700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88801b0fc780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88801b0fc800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================