================================================================== 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 ffff0000e3b2a010 by task syz-executor.3/11843 CPU: 0 PID: 11843 Comm: syz-executor.3 Not tainted 6.3.0-rc7-syzkaller-g14f8db1c0f9a #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/14/2023 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:319 [inline] print_report+0x174/0x514 mm/kasan/report.c:430 kasan_report+0xd4/0x130 mm/kasan/report.c:536 __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 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] do_notify_resume+0x2180/0x3c90 arch/arm64/kernel/signal.c:1304 prepare_exit_to_user_mode arch/arm64/kernel/entry-common.c:137 [inline] exit_to_user_mode arch/arm64/kernel/entry-common.c:142 [inline] el0_svc+0x90/0x15c arch/arm64/kernel/entry-common.c:638 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655 el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:591 Allocated by task 11849: 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:1066 kmalloc include/linux/slab.h:580 [inline] kzalloc include/linux/slab.h:720 [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:3560 [inline] path_openat+0x1f2c/0x27f8 fs/namei.c:3715 do_filp_open+0x1bc/0x3cc fs/namei.c:3742 do_sys_openat2+0x128/0x3d8 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] __arm64_sys_openat+0x1f0/0x240 fs/open.c:1375 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x2c0 arch/arm64/kernel/syscall.c:52 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142 do_el0_svc+0x64/0x198 arch/arm64/kernel/syscall.c:193 el0_svc+0x4c/0x15c arch/arm64/kernel/entry-common.c:637 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655 el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:591 Freed by task 11846: 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:3787 [inline] __kmem_cache_free+0x2a8/0x49c mm/slub.c:3800 kfree+0xb8/0x19c mm/slab_common.c:1019 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:1304 prepare_exit_to_user_mode arch/arm64/kernel/entry-common.c:137 [inline] exit_to_user_mode arch/arm64/kernel/entry-common.c:142 [inline] el0_svc+0x90/0x15c arch/arm64/kernel/entry-common.c:638 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655 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:1361 __queue_work+0xd3c/0x1374 kernel/workqueue.c:1524 queue_work_on+0x9c/0x128 kernel/workqueue.c:1552 queue_work include/linux/workqueue.h:504 [inline] schedule_work include/linux/workqueue.h:565 [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:3560 [inline] path_openat+0x1f2c/0x27f8 fs/namei.c:3715 do_filp_open+0x1bc/0x3cc fs/namei.c:3742 do_sys_openat2+0x128/0x3d8 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] __arm64_sys_openat+0x1f0/0x240 fs/open.c:1375 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x2c0 arch/arm64/kernel/syscall.c:52 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142 do_el0_svc+0x64/0x198 arch/arm64/kernel/syscall.c:193 el0_svc+0x4c/0x15c arch/arm64/kernel/entry-common.c:637 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655 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:1361 __queue_work+0xd3c/0x1374 kernel/workqueue.c:1524 queue_work_on+0x9c/0x128 kernel/workqueue.c:1552 queue_work include/linux/workqueue.h:504 [inline] schedule_work include/linux/workqueue.h:565 [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:3560 [inline] path_openat+0x1f2c/0x27f8 fs/namei.c:3715 do_filp_open+0x1bc/0x3cc fs/namei.c:3742 do_sys_openat2+0x128/0x3d8 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] __arm64_sys_openat+0x1f0/0x240 fs/open.c:1375 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x2c0 arch/arm64/kernel/syscall.c:52 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142 do_el0_svc+0x64/0x198 arch/arm64/kernel/syscall.c:193 el0_svc+0x4c/0x15c arch/arm64/kernel/entry-common.c:637 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655 el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:591 The buggy address belongs to the object at ffff0000e3b2a000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 16 bytes inside of freed 2048-byte region [ffff0000e3b2a000, ffff0000e3b2a800) The buggy address belongs to the physical page: page:00000000698ee52b refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x123b28 head:00000000698ee52b order:3 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0x5ffc00000010200(slab|head|node=0|zone=2|lastcpupid=0x7ff) raw: 05ffc00000010200 ffff0000c0002900 fffffc0003245e00 dead000000000002 raw: 0000000000000000 0000000000080008 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff0000e3b29f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff0000e3b29f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff0000e3b2a000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff0000e3b2a080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff0000e3b2a100: 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 = 0x0000000096000006 EC = 0x25: DABT (current EL), IL = 32 bits SET = 0, FnV = 0 EA = 0, S1PTW = 0 FSC = 0x06: level 2 translation fault Data abort info: ISV = 0, ISS = 0x00000006 CM = 0, WnR = 0 [dfff800000000002] address between user and kernel address ranges Internal error: Oops: 0000000096000006 [#1] PREEMPT SMP Modules linked in: CPU: 1 PID: 11843 Comm: syz-executor.3 Tainted: G B 6.3.0-rc7-syzkaller-g14f8db1c0f9a #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/14/2023 pstate: 00400005 (nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : nfc_llcp_find_local net/nfc/llcp_core.c:287 [inline] pc : nfc_llcp_unregister_device+0x5c/0x11c net/nfc/llcp_core.c:1611 lr : nfc_llcp_unregister_device+0x48/0x11c net/nfc/llcp_core.c:1611 sp : ffff800022bc7810 x29: ffff800022bc7810 x28: 1fffe0001ae2e2df x27: 1fffe0001ae2e2d5 x26: ffff0000d71716a8 x25: ffff0000cc5bc650 x24: 1fffe00019fa08c1 x23: ffff800018927f60 x22: dfff800000000000 x21: 0000000000000010 x20: ffff0000cfd04000 x19: 0000000000000000 x18: 1fffe0003684e9b6 x17: 0000000000000000 x16: ffff800008966724 x15: 0000000000000001 x14: 0000000000000000 x13: 0000000000000001 x12: 0000000000000001 x11: 0000000000000000 x10: 0000000000000000 x9 : ffff80001a10c690 x8 : 0000000000000002 x7 : 0000000000000001 x6 : 0000000000000001 x5 : ffff800022bc7018 x4 : ffff800015e4ccc0 x3 : ffff80001212dc38 x2 : 0000000000000000 x1 : 0000000000000008 x0 : 0000000000000000 Call trace: nfc_llcp_find_local net/nfc/llcp_core.c:287 [inline] nfc_llcp_unregister_device+0x5c/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 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] do_notify_resume+0x2180/0x3c90 arch/arm64/kernel/signal.c:1304 prepare_exit_to_user_mode arch/arm64/kernel/entry-common.c:137 [inline] exit_to_user_mode arch/arm64/kernel/entry-common.c:142 [inline] el0_svc+0x90/0x15c arch/arm64/kernel/entry-common.c:638 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655 el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:591 Code: eb17027f 54000180 91004275 d343fea8 (38766908) ---[ end trace 0000000000000000 ]--- ---------------- Code disassembly (best guess): 0: eb17027f cmp x19, x23 4: 54000180 b.eq 0x34 // b.none 8: 91004275 add x21, x19, #0x10 c: d343fea8 lsr x8, x21, #3 * 10: 38766908 ldrb w8, [x8, x22] <-- trapping instruction