================================================================== BUG: KASAN: use-after-free in nfc_llcp_find_local+0xcf/0xe0 net/nfc/llcp_core.c:285 Read of size 8 at addr ffff8880758fa000 by task syz-executor.2/22838 CPU: 0 PID: 22838 Comm: syz-executor.2 Not tainted 6.1.0-next-20221219-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd1/0x138 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:306 [inline] print_report+0x15e/0x45d mm/kasan/report.c:417 kasan_report+0xc0/0xf0 mm/kasan/report.c:517 nfc_llcp_find_local+0xcf/0xe0 net/nfc/llcp_core.c:285 nfc_llcp_unregister_device+0x1a/0x260 net/nfc/llcp_core.c:1610 nfc_unregister_device+0x196/0x330 net/nfc/core.c:1179 virtual_ncidev_close+0x52/0xb0 drivers/nfc/virtual_ncidev.c:163 __fput+0x27c/0xa90 fs/file_table.c:320 task_work_run+0x16f/0x270 kernel/task_work.c:179 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop kernel/entry/common.c:171 [inline] exit_to_user_mode_prepare+0x23c/0x250 kernel/entry/common.c:203 __syscall_exit_to_user_mode_work kernel/entry/common.c:285 [inline] syscall_exit_to_user_mode+0x1d/0x50 kernel/entry/common.c:296 do_syscall_64+0x46/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f238743df8b Code: 0f 05 48 3d 00 f0 ff ff 77 45 c3 0f 1f 40 00 48 83 ec 18 89 7c 24 0c e8 63 fc ff ff 8b 7c 24 0c 41 89 c0 b8 03 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 35 44 89 c7 89 44 24 0c e8 a1 fc ff ff 8b 44 RSP: 002b:00007fffec53fac0 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000004 RCX: 00007f238743df8b RDX: 0000000000000000 RSI: 00007f2386e252d8 RDI: 0000000000000003 RBP: 00007f23875ad980 R08: 0000000000000000 R09: 000000008acd333c R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000042ed3 R13: 00007fffec53fbc0 R14: 00007f23875ac050 R15: 0000000000000032 Allocated by task 22842: 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:371 [inline] ____kasan_kmalloc mm/kasan/common.c:330 [inline] __kasan_kmalloc+0xa5/0xb0 mm/kasan/common.c:380 kmalloc include/linux/slab.h:580 [inline] kzalloc include/linux/slab.h:720 [inline] nfc_llcp_register_device+0x49/0x9e0 net/nfc/llcp_core.c:1566 nfc_register_device+0x70/0x3b0 net/nfc/core.c:1124 nci_register_device+0x7cb/0xb50 net/nfc/nci/core.c:1257 virtual_ncidev_open+0x14f/0x230 drivers/nfc/virtual_ncidev.c:148 misc_open+0x37a/0x4a0 drivers/char/misc.c:165 chrdev_open+0x26a/0x770 fs/char_dev.c:414 do_dentry_open+0x6cc/0x13f0 fs/open.c:882 do_open fs/namei.c:3557 [inline] path_openat+0x1bbc/0x2a50 fs/namei.c:3714 do_filp_open+0x1ba/0x410 fs/namei.c:3741 do_sys_openat2+0x16d/0x4c0 fs/open.c:1310 do_sys_open fs/open.c:1326 [inline] __do_sys_openat fs/open.c:1342 [inline] __se_sys_openat fs/open.c:1337 [inline] __x64_sys_openat+0x143/0x1f0 fs/open.c:1337 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 Freed by task 22840: 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:518 ____kasan_slab_free mm/kasan/common.c:236 [inline] ____kasan_slab_free+0x160/0x1c0 mm/kasan/common.c:200 kasan_slab_free include/linux/kasan.h:177 [inline] slab_free_hook mm/slub.c:1781 [inline] slab_free_freelist_hook+0x8b/0x1c0 mm/slub.c:1807 slab_free mm/slub.c:3787 [inline] __kmem_cache_free+0xaf/0x3b0 mm/slub.c:3800 local_release net/nfc/llcp_core.c:173 [inline] kref_put include/linux/kref.h:65 [inline] nfc_llcp_local_put net/nfc/llcp_core.c:181 [inline] nfc_llcp_local_put net/nfc/llcp_core.c:176 [inline] nfc_llcp_unregister_device+0x1ba/0x260 net/nfc/llcp_core.c:1619 nfc_unregister_device+0x196/0x330 net/nfc/core.c:1179 virtual_ncidev_close+0x52/0xb0 drivers/nfc/virtual_ncidev.c:163 __fput+0x27c/0xa90 fs/file_table.c:320 task_work_run+0x16f/0x270 kernel/task_work.c:179 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop kernel/entry/common.c:171 [inline] exit_to_user_mode_prepare+0x23c/0x250 kernel/entry/common.c:203 __syscall_exit_to_user_mode_work kernel/entry/common.c:285 [inline] syscall_exit_to_user_mode+0x1d/0x50 kernel/entry/common.c:296 do_syscall_64+0x46/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x63/0xcd Last potentially related work creation: kasan_save_stack+0x22/0x40 mm/kasan/common.c:45 __kasan_record_aux_stack+0xbc/0xd0 mm/kasan/generic.c:488 __call_rcu_common.constprop.0+0x99/0x780 kernel/rcu/tree.c:2755 netlink_release+0xdcb/0x1e60 net/netlink/af_netlink.c:826 __sock_release+0xcd/0x280 net/socket.c:650 sock_close+0x1c/0x20 net/socket.c:1365 __fput+0x27c/0xa90 fs/file_table.c:320 task_work_run+0x16f/0x270 kernel/task_work.c:179 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop kernel/entry/common.c:171 [inline] exit_to_user_mode_prepare+0x23c/0x250 kernel/entry/common.c:203 __syscall_exit_to_user_mode_work kernel/entry/common.c:285 [inline] syscall_exit_to_user_mode+0x1d/0x50 kernel/entry/common.c:296 do_syscall_64+0x46/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x63/0xcd Second to last potentially related work creation: kasan_save_stack+0x22/0x40 mm/kasan/common.c:45 __kasan_record_aux_stack+0xbc/0xd0 mm/kasan/generic.c:488 __call_rcu_common.constprop.0+0x99/0x780 kernel/rcu/tree.c:2755 netlink_release+0xdcb/0x1e60 net/netlink/af_netlink.c:826 __sock_release+0xcd/0x280 net/socket.c:650 sock_close+0x1c/0x20 net/socket.c:1365 __fput+0x27c/0xa90 fs/file_table.c:320 task_work_run+0x16f/0x270 kernel/task_work.c:179 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop kernel/entry/common.c:171 [inline] exit_to_user_mode_prepare+0x23c/0x250 kernel/entry/common.c:203 __syscall_exit_to_user_mode_work kernel/entry/common.c:285 [inline] syscall_exit_to_user_mode+0x1d/0x50 kernel/entry/common.c:296 do_syscall_64+0x46/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x63/0xcd The buggy address belongs to the object at ffff8880758fa000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 0 bytes inside of 2048-byte region [ffff8880758fa000, ffff8880758fa800) The buggy address belongs to the physical page: page:ffffea0001d63e00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x758f8 head:ffffea0001d63e00 order:3 compound_mapcount:0 subpages_mapcount:0 compound_pincount:0 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 ffff888012442000 dead000000000100 dead000000000122 raw: 0000000000000000 0000000080080008 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 26, tgid 26 (kworker/1:1), ts 93725524288, free_ts 93663132425 prep_new_page mm/page_alloc.c:2531 [inline] get_page_from_freelist+0x119e/0x2a80 mm/page_alloc.c:4283 __alloc_pages+0x1cb/0x5b0 mm/page_alloc.c:5549 alloc_pages+0x1aa/0x270 mm/mempolicy.c:2282 alloc_slab_page mm/slub.c:1851 [inline] allocate_slab+0x25f/0x350 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+0x1a4/0x430 mm/slub.c:3491 __do_kmalloc_node mm/slab_common.c:967 [inline] __kmalloc_node_track_caller+0x4b/0xc0 mm/slab_common.c:988 kmalloc_reserve net/core/skbuff.c:492 [inline] __alloc_skb+0xe9/0x310 net/core/skbuff.c:565 alloc_skb include/linux/skbuff.h:1270 [inline] alloc_skb_with_frags+0x97/0x6c0 net/core/skbuff.c:6195 sock_alloc_send_pskb+0x7a7/0x930 net/core/sock.c:2741 sock_alloc_send_skb include/net/sock.h:1884 [inline] mld_newpack.isra.0+0x1b9/0x770 net/ipv6/mcast.c:1748 add_grhead+0x295/0x340 net/ipv6/mcast.c:1851 add_grec+0x1082/0x1560 net/ipv6/mcast.c:1989 mld_send_initial_cr.part.0+0xf6/0x230 net/ipv6/mcast.c:2236 mld_send_initial_cr net/ipv6/mcast.c:1232 [inline] mld_dad_work+0x1d7/0x680 net/ipv6/mcast.c:2262 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1446 [inline] free_pcp_prepare+0x4d0/0x9e0 mm/page_alloc.c:1496 free_unref_page_prepare mm/page_alloc.c:3369 [inline] free_unref_page+0x1d/0x490 mm/page_alloc.c:3464 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+0x66/0x90 mm/kasan/common.c:302 kasan_slab_alloc include/linux/kasan.h:201 [inline] slab_post_alloc_hook mm/slab.h:761 [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+0x1e4/0x430 mm/slub.c:3476 getname_flags.part.0+0x50/0x4f0 fs/namei.c:139 getname_flags include/linux/audit.h:320 [inline] getname+0x92/0xd0 fs/namei.c:218 do_sys_openat2+0xf5/0x4c0 fs/open.c:1304 do_sys_open fs/open.c:1326 [inline] __do_sys_openat fs/open.c:1342 [inline] __se_sys_openat fs/open.c:1337 [inline] __x64_sys_openat+0x143/0x1f0 fs/open.c:1337 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 Memory state around the buggy address: ffff8880758f9f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8880758f9f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff8880758fa000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880758fa080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880758fa100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================