================================================================== BUG: KASAN: slab-use-after-free in hci_uart_write_work+0x82d/0x960 drivers/bluetooth/hci_ldisc.c:165 Read of size 4 at addr ffff88801216a930 by task kworker/0:1/10 CPU: 0 UID: 0 PID: 10 Comm: kworker/0:1 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 Workqueue: events hci_uart_write_work Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0xcd/0x630 mm/kasan/report.c:482 kasan_report+0xe0/0x110 mm/kasan/report.c:595 hci_uart_write_work+0x82d/0x960 drivers/bluetooth/hci_ldisc.c:165 process_one_work+0x9ba/0x1b20 kernel/workqueue.c:3257 process_scheduled_works kernel/workqueue.c:3340 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3421 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x983/0xb10 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 Allocated by task 6004: kasan_save_stack+0x33/0x60 mm/kasan/common.c:56 kasan_save_track+0x14/0x30 mm/kasan/common.c:77 unpoison_slab_object mm/kasan/common.c:339 [inline] __kasan_slab_alloc+0x89/0x90 mm/kasan/common.c:365 kasan_slab_alloc include/linux/kasan.h:252 [inline] slab_post_alloc_hook mm/slub.c:4953 [inline] slab_alloc_node mm/slub.c:5263 [inline] kmem_cache_alloc_node_noprof+0x298/0x800 mm/slub.c:5315 __alloc_skb+0x156/0x410 net/core/skbuff.c:679 alloc_skb include/linux/skbuff.h:1383 [inline] bcsp_prepare_pkt+0xe0/0xae0 drivers/bluetooth/hci_bcsp.c:218 bcsp_dequeue+0x237/0x4b0 drivers/bluetooth/hci_bcsp.c:308 hci_uart_dequeue drivers/bluetooth/hci_ldisc.c:107 [inline] hci_uart_write_work+0x4e3/0x960 drivers/bluetooth/hci_ldisc.c:161 process_one_work+0x9ba/0x1b20 kernel/workqueue.c:3257 process_scheduled_works kernel/workqueue.c:3340 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3421 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x983/0xb10 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 The buggy address belongs to the object at ffff88801216a8c0 which belongs to the cache skbuff_head_cache of size 240 The buggy address is located 112 bytes inside of freed 240-byte region [ffff88801216a8c0, ffff88801216a9b0) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1216a head: order:1 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 ksm flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000040 ffff88801c32c8c0 ffffea0000956680 dead000000000003 raw: 0000000000000000 0000000000190019 00000000f5000000 0000000000000000 head: 00fff00000000040 ffff88801c32c8c0 ffffea0000956680 dead000000000003 head: 0000000000000000 0000000000190019 00000000f5000000 0000000000000000 head: 00fff00000000001 ffffea0000485a81 00000000ffffffff 00000000ffffffff head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000002 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 1, migratetype Unmovable, gfp_mask 0x52820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 8016, tgid 8016 (kworker/u32:46), ts 326323281246, free_ts 253086368769 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1af/0x220 mm/page_alloc.c:1846 prep_new_page mm/page_alloc.c:1854 [inline] get_page_from_freelist+0xd0b/0x31a0 mm/page_alloc.c:3915 __alloc_pages_slowpath mm/page_alloc.c:4741 [inline] __alloc_frozen_pages_noprof+0x6d7/0x2430 mm/page_alloc.c:5223 alloc_pages_mpol+0x1fb/0x550 mm/mempolicy.c:2486 alloc_slab_page mm/slub.c:3075 [inline] allocate_slab mm/slub.c:3248 [inline] new_slab+0x2c3/0x430 mm/slub.c:3302 ___slab_alloc+0xe18/0x1c90 mm/slub.c:4656 __slab_alloc.constprop.0+0x63/0x110 mm/slub.c:4779 __slab_alloc_node mm/slub.c:4855 [inline] slab_alloc_node mm/slub.c:5251 [inline] kmem_cache_alloc_node_noprof+0x44a/0x800 mm/slub.c:5315 __alloc_skb+0x156/0x410 net/core/skbuff.c:679 skb_copy+0x1c9/0x3a0 net/core/skbuff.c:2162 mac80211_hwsim_tx_frame_no_nl.isra.0+0xb6e/0x13c0 drivers/net/wireless/virtual/mac80211_hwsim.c:1891 mac80211_hwsim_tx_frame+0x1f1/0x2a0 drivers/net/wireless/virtual/mac80211_hwsim.c:2264 __mac80211_hwsim_beacon_tx drivers/net/wireless/virtual/mac80211_hwsim.c:2281 [inline] mac80211_hwsim_beacon_tx+0x595/0xa40 drivers/net/wireless/virtual/mac80211_hwsim.c:2365 __iterate_interfaces+0x2e5/0x650 net/mac80211/util.c:761 ieee80211_iterate_active_interfaces_atomic+0x71/0x1b0 net/mac80211/util.c:797 mac80211_hwsim_beacon+0x105/0x1b0 drivers/net/wireless/virtual/mac80211_hwsim.c:2395 page last free pid 9900 tgid 9900 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1395 [inline] __free_pages_ok+0x725/0xf80 mm/page_alloc.c:1571 p9_fid_destroy+0x9a/0xd0 net/9p/client.c:768 p9_client_clunk+0x12a/0x170 net/9p/client.c:1346 p9_fid_put include/net/9p/client.h:376 [inline] v9fs_dir_release+0x43c/0x590 fs/9p/vfs_dir.c:224 __fput+0x402/0xb70 fs/file_table.c:468 task_work_run+0x150/0x240 kernel/task_work.c:233 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] __exit_to_user_mode_loop kernel/entry/common.c:44 [inline] exit_to_user_mode_loop+0xfb/0x540 kernel/entry/common.c:75 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline] __do_fast_syscall_32+0x4a4/0x680 arch/x86/entry/syscall_32.c:310 do_fast_syscall_32+0x32/0x80 arch/x86/entry/syscall_32.c:332 entry_SYSENTER_compat_after_hwframe+0x84/0x8e Memory state around the buggy address: ffff88801216a800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fc fc ffff88801216a880: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb >ffff88801216a900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88801216a980: fb fb fb fb fb fb fc fc fc fc fc fc fc fc fc fc ffff88801216aa00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================