================================================================== BUG: KASAN: slab-use-after-free in nfc_llcp_find_local net/nfc/llcp_core.c:287 [inline] BUG: KASAN: slab-use-after-free in nfc_llcp_unregister_device+0x6c/0x11c net/nfc/llcp_core.c:1611 Read of size 8 at addr ffff0000cfb59010 by task syz-executor.5/25671 CPU: 1 PID: 25671 Comm: syz-executor.5 Not tainted 6.4.0-rc7-syzkaller-ge40939bbfc68 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/27/2023 Call trace: dump_backtrace+0x1b8/0x1e4 arch/arm64/kernel/stacktrace.c:233 show_stack+0x2c/0x44 arch/arm64/kernel/stacktrace.c:240 __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd0/0x124 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:351 [inline] print_report+0x174/0x514 mm/kasan/report.c:462 kasan_report+0xd4/0x130 mm/kasan/report.c:572 __asan_report_load8_noabort+0x20/0x2c mm/kasan/report_generic.c:381 nfc_llcp_find_local net/nfc/llcp_core.c:287 [inline] nfc_llcp_unregister_device+0x6c/0x11c net/nfc/llcp_core.c:1611 nfc_unregister_device+0x150/0x290 net/nfc/core.c:1179 nci_unregister_device+0x1dc/0x21c net/nfc/nci/core.c:1303 virtual_ncidev_close+0x5c/0xa0 drivers/nfc/virtual_ncidev.c:163 __fput+0x30c/0x7bc fs/file_table.c:321 ____fput+0x20/0x30 fs/file_table.c:349 task_work_run+0x230/0x2e0 kernel/task_work.c:179 exit_task_work include/linux/task_work.h:38 [inline] do_exit+0x63c/0x1f58 kernel/exit.c:874 do_group_exit+0x194/0x22c kernel/exit.c:1024 get_signal+0x14b0/0x159c kernel/signal.c:2876 do_signal arch/arm64/kernel/signal.c:1249 [inline] do_notify_resume+0x3cc/0x3c90 arch/arm64/kernel/signal.c:1302 exit_to_user_mode_prepare arch/arm64/kernel/entry-common.c:137 [inline] exit_to_user_mode arch/arm64/kernel/entry-common.c:144 [inline] el0_svc+0x94/0x160 arch/arm64/kernel/entry-common.c:648 el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:665 el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:591 Allocated by task 25676: kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4c/0x7c mm/kasan/common.c:52 kasan_save_alloc_info+0x24/0x30 mm/kasan/generic.c:510 ____kasan_kmalloc mm/kasan/common.c:374 [inline] __kasan_kmalloc+0xac/0xc4 mm/kasan/common.c:383 kasan_kmalloc include/linux/kasan.h:196 [inline] kmalloc_trace+0x70/0x88 mm/slab_common.c:1062 kmalloc include/linux/slab.h:559 [inline] kzalloc include/linux/slab.h:680 [inline] nfc_llcp_register_device+0x60/0x6bc net/nfc/llcp_core.c:1567 nfc_register_device+0x8c/0x310 net/nfc/core.c:1124 nci_register_device+0x6ac/0x7c4 net/nfc/nci/core.c:1257 virtual_ncidev_open+0x13c/0x1bc drivers/nfc/virtual_ncidev.c:148 misc_open+0x2f0/0x368 drivers/char/misc.c:165 chrdev_open+0x3e8/0x4fc fs/char_dev.c:414 do_dentry_open+0x724/0xf90 fs/open.c:920 vfs_open+0x7c/0x90 fs/open.c:1051 do_open fs/namei.c:3636 [inline] path_openat+0x1f2c/0x27f8 fs/namei.c:3791 do_filp_open+0x1bc/0x3cc fs/namei.c:3818 do_sys_openat2+0x128/0x3d8 fs/open.c:1356 do_sys_open fs/open.c:1372 [inline] __do_sys_openat fs/open.c:1388 [inline] __se_sys_openat fs/open.c:1383 [inline] __arm64_sys_openat+0x1f0/0x240 fs/open.c:1383 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x2c0 arch/arm64/kernel/syscall.c:52 el0_svc_common+0x138/0x244 arch/arm64/kernel/syscall.c:142 do_el0_svc+0x64/0x198 arch/arm64/kernel/syscall.c:191 el0_svc+0x4c/0x160 arch/arm64/kernel/entry-common.c:647 el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:665 el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:591 Freed by task 25674: kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4c/0x7c mm/kasan/common.c:52 kasan_save_free_info+0x38/0x5c mm/kasan/generic.c:521 ____kasan_slab_free+0x144/0x1c0 mm/kasan/common.c:236 __kasan_slab_free+0x18/0x28 mm/kasan/common.c:244 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:3786 [inline] __kmem_cache_free+0x2a8/0x49c mm/slub.c:3799 kfree+0xb8/0x19c mm/slab_common.c:1015 local_release net/nfc/llcp_core.c:174 [inline] kref_put include/linux/kref.h:65 [inline] nfc_llcp_local_put+0x15c/0x1b4 net/nfc/llcp_core.c:182 nfc_llcp_unregister_device+0xa4/0x11c net/nfc/llcp_core.c:1620 nfc_unregister_device+0x150/0x290 net/nfc/core.c:1179 nci_unregister_device+0x1dc/0x21c net/nfc/nci/core.c:1303 virtual_ncidev_close+0x5c/0xa0 drivers/nfc/virtual_ncidev.c:163 __fput+0x30c/0x7bc fs/file_table.c:321 ____fput+0x20/0x30 fs/file_table.c:349 task_work_run+0x230/0x2e0 kernel/task_work.c:179 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] do_notify_resume+0x2180/0x3c90 arch/arm64/kernel/signal.c:1305 exit_to_user_mode_prepare arch/arm64/kernel/entry-common.c:137 [inline] exit_to_user_mode arch/arm64/kernel/entry-common.c:144 [inline] el0_svc+0x94/0x160 arch/arm64/kernel/entry-common.c:648 el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:665 el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:591 Last potentially related work creation: kasan_save_stack+0x40/0x6c mm/kasan/common.c:45 __kasan_record_aux_stack+0xcc/0xe8 mm/kasan/generic.c:491 kasan_record_aux_stack_noalloc+0x14/0x20 mm/kasan/generic.c:501 insert_work+0x64/0x384 kernel/workqueue.c:1365 __queue_work+0xd3c/0x1374 kernel/workqueue.c:1526 queue_work_on+0x9c/0x128 kernel/workqueue.c:1554 queue_work include/linux/workqueue.h:505 [inline] schedule_work include/linux/workqueue.h:566 [inline] rfkill_register+0x65c/0x7a4 net/rfkill/core.c:1090 nfc_register_device+0x148/0x310 net/nfc/core.c:1132 nci_register_device+0x6ac/0x7c4 net/nfc/nci/core.c:1257 virtual_ncidev_open+0x13c/0x1bc drivers/nfc/virtual_ncidev.c:148 misc_open+0x2f0/0x368 drivers/char/misc.c:165 chrdev_open+0x3e8/0x4fc fs/char_dev.c:414 do_dentry_open+0x724/0xf90 fs/open.c:920 vfs_open+0x7c/0x90 fs/open.c:1051 do_open fs/namei.c:3636 [inline] path_openat+0x1f2c/0x27f8 fs/namei.c:3791 do_filp_open+0x1bc/0x3cc fs/namei.c:3818 do_sys_openat2+0x128/0x3d8 fs/open.c:1356 do_sys_open fs/open.c:1372 [inline] __do_sys_openat fs/open.c:1388 [inline] __se_sys_openat fs/open.c:1383 [inline] __arm64_sys_openat+0x1f0/0x240 fs/open.c:1383 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x2c0 arch/arm64/kernel/syscall.c:52 el0_svc_common+0x138/0x244 arch/arm64/kernel/syscall.c:142 do_el0_svc+0x64/0x198 arch/arm64/kernel/syscall.c:191 el0_svc+0x4c/0x160 arch/arm64/kernel/entry-common.c:647 el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:665 el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:591 Second to last potentially related work creation: kasan_save_stack+0x40/0x6c mm/kasan/common.c:45 __kasan_record_aux_stack+0xcc/0xe8 mm/kasan/generic.c:491 kasan_record_aux_stack_noalloc+0x14/0x20 mm/kasan/generic.c:501 insert_work+0x64/0x384 kernel/workqueue.c:1365 __queue_work+0xd3c/0x1374 kernel/workqueue.c:1526 queue_work_on+0x9c/0x128 kernel/workqueue.c:1554 queue_work include/linux/workqueue.h:505 [inline] schedule_work include/linux/workqueue.h:566 [inline] rfkill_register+0x65c/0x7a4 net/rfkill/core.c:1090 nfc_register_device+0x148/0x310 net/nfc/core.c:1132 nci_register_device+0x6ac/0x7c4 net/nfc/nci/core.c:1257 virtual_ncidev_open+0x13c/0x1bc drivers/nfc/virtual_ncidev.c:148 misc_open+0x2f0/0x368 drivers/char/misc.c:165 chrdev_open+0x3e8/0x4fc fs/char_dev.c:414 do_dentry_open+0x724/0xf90 fs/open.c:920 vfs_open+0x7c/0x90 fs/open.c:1051 do_open fs/namei.c:3636 [inline] path_openat+0x1f2c/0x27f8 fs/namei.c:3791 do_filp_open+0x1bc/0x3cc fs/namei.c:3818 do_sys_openat2+0x128/0x3d8 fs/open.c:1356 do_sys_open fs/open.c:1372 [inline] __do_sys_openat fs/open.c:1388 [inline] __se_sys_openat fs/open.c:1383 [inline] __arm64_sys_openat+0x1f0/0x240 fs/open.c:1383 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x2c0 arch/arm64/kernel/syscall.c:52 el0_svc_common+0x138/0x244 arch/arm64/kernel/syscall.c:142 do_el0_svc+0x64/0x198 arch/arm64/kernel/syscall.c:191 el0_svc+0x4c/0x160 arch/arm64/kernel/entry-common.c:647 el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:665 el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:591 The buggy address belongs to the object at ffff0000cfb59000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 16 bytes inside of freed 2048-byte region [ffff0000cfb59000, ffff0000cfb59800) The buggy address belongs to the physical page: page:0000000013e33a51 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x10fb58 head:0000000013e33a51 order:3 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0x5ffc00000010200(slab|head|node=0|zone=2|lastcpupid=0x7ff) page_type: 0xffffffff() raw: 05ffc00000010200 ffff0000c0002900 fffffc00033c6c00 dead000000000002 raw: 0000000000000000 0000000000080008 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff0000cfb58f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff0000cfb58f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff0000cfb59000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff0000cfb59080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff0000cfb59100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== Unable to handle kernel paging request at virtual address dfff800000000002 KASAN: null-ptr-deref in range [0x0000000000000010-0x0000000000000017] Mem abort info: ESR = 0x0000000096000005