================================================================== BUG: KASAN: use-after-free in hci_cmd_timeout+0x239/0x250 net/bluetooth/hci_core.c:1485 Read of size 8 at addr ffff88801c995858 by task kworker/1:0/22 CPU: 1 PID: 22 Comm: kworker/1:0 Not tainted 6.0.0-rc5-syzkaller-00721-g80e78fcce86d #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/26/2022 Workqueue: events hci_cmd_timeout Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:317 [inline] print_report.cold+0x2ba/0x719 mm/kasan/report.c:433 kasan_report+0xb1/0x1e0 mm/kasan/report.c:495 hci_cmd_timeout+0x239/0x250 net/bluetooth/hci_core.c:1485 process_one_work+0x991/0x1610 kernel/workqueue.c:2289 worker_thread+0x665/0x1080 kernel/workqueue.c:2436 kthread+0x2e4/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306 Allocated by task 3745: kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38 kasan_set_track mm/kasan/common.c:45 [inline] set_alloc_info mm/kasan/common.c:437 [inline] __kasan_slab_alloc+0x90/0xc0 mm/kasan/common.c:470 kasan_slab_alloc include/linux/kasan.h:224 [inline] slab_post_alloc_hook mm/slab.h:727 [inline] slab_alloc_node mm/slub.c:3243 [inline] slab_alloc mm/slub.c:3251 [inline] __kmem_cache_alloc_lru mm/slub.c:3258 [inline] kmem_cache_alloc+0x267/0x3b0 mm/slub.c:3268 skb_clone+0x16e/0x3c0 net/core/skbuff.c:1547 hci_cmd_work+0x191/0x430 net/bluetooth/hci_core.c:4048 process_one_work+0x991/0x1610 kernel/workqueue.c:2289 worker_thread+0x665/0x1080 kernel/workqueue.c:2436 kthread+0x2e4/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306 Freed by task 3735: kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38 kasan_set_track+0x21/0x30 mm/kasan/common.c:45 kasan_set_free_info+0x20/0x30 mm/kasan/generic.c:370 ____kasan_slab_free mm/kasan/common.c:367 [inline] ____kasan_slab_free+0x166/0x1c0 mm/kasan/common.c:329 kasan_slab_free include/linux/kasan.h:200 [inline] slab_free_hook mm/slub.c:1754 [inline] slab_free_freelist_hook+0x8b/0x1c0 mm/slub.c:1780 slab_free mm/slub.c:3534 [inline] kmem_cache_free+0xeb/0x5b0 mm/slub.c:3551 kfree_skbmem+0xef/0x1b0 net/core/skbuff.c:714 kfree_skb_reason+0x85/0x110 include/linux/refcount.h:279 kfree_skb include/linux/skbuff.h:1206 [inline] hci_dev_open_sync+0xbe2/0x2190 net/bluetooth/hci_sync.c:4377 hci_dev_do_open+0x2d/0x70 net/bluetooth/hci_core.c:483 hci_power_on+0xda/0x620 net/bluetooth/hci_core.c:975 process_one_work+0x991/0x1610 kernel/workqueue.c:2289 worker_thread+0x665/0x1080 kernel/workqueue.c:2436 kthread+0x2e4/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306 The buggy address belongs to the object at ffff88801c995780 which belongs to the cache skbuff_head_cache of size 240 The buggy address is located 216 bytes inside of 240-byte region [ffff88801c995780, ffff88801c995870) The buggy address belongs to the physical page: page:ffffea0000726540 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1c995 flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000000200 ffffea00009bff00 dead000000000005 ffff8880127b6500 raw: 0000000000000000 00000000000c000c 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 0, migratetype Unmovable, gfp_mask 0x112a20(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_HARDWALL), pid 3881, tgid 3880 (syz-executor.1), ts 82175197933, free_ts 82127111862 prep_new_page mm/page_alloc.c:2532 [inline] get_page_from_freelist+0x109b/0x2ce0 mm/page_alloc.c:4283 __alloc_pages+0x1c7/0x510 mm/page_alloc.c:5515 alloc_pages+0x1a6/0x270 mm/mempolicy.c:2270 alloc_slab_page mm/slub.c:1824 [inline] allocate_slab+0x27e/0x3d0 mm/slub.c:1969 new_slab mm/slub.c:2029 [inline] ___slab_alloc+0x7f1/0xe10 mm/slub.c:3031 __slab_alloc.constprop.0+0x4d/0xa0 mm/slub.c:3118 slab_alloc_node mm/slub.c:3209 [inline] kmem_cache_alloc_node+0x11d/0x3f0 mm/slub.c:3293 __alloc_skb+0x210/0x2f0 net/core/skbuff.c:422 alloc_skb include/linux/skbuff.h:1257 [inline] bt_skb_alloc include/net/bluetooth/bluetooth.h:469 [inline] hci_si_event net/bluetooth/hci_sock.c:726 [inline] hci_sock_dev_event+0x15a/0x5f0 net/bluetooth/hci_sock.c:768 hci_unregister_dev+0x216/0x4e0 net/bluetooth/hci_core.c:2696 hci_uart_tty_close+0x1bf/0x290 drivers/bluetooth/hci_ldisc.c:548 tty_ldisc_close+0x110/0x190 drivers/tty/tty_ldisc.c:456 tty_ldisc_kill+0x94/0x150 drivers/tty/tty_ldisc.c:608 tty_ldisc_release+0xe1/0x2a0 drivers/tty/tty_ldisc.c:776 tty_release_struct+0x20/0xe0 drivers/tty/tty_io.c:1694 tty_release+0xc70/0x1200 drivers/tty/tty_io.c:1865 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1449 [inline] free_pcp_prepare+0x5e4/0xd20 mm/page_alloc.c:1499 free_unref_page_prepare mm/page_alloc.c:3380 [inline] free_unref_page+0x19/0x4d0 mm/page_alloc.c:3476 __vunmap+0x85d/0xd30 mm/vmalloc.c:2696 __vfree+0x3c/0xd0 mm/vmalloc.c:2744 vfree+0x5a/0x90 mm/vmalloc.c:2775 n_tty_close+0xcf/0x1e0 drivers/tty/n_tty.c:1861 tty_ldisc_close+0x110/0x190 drivers/tty/tty_ldisc.c:456 tty_set_ldisc+0x214/0x680 drivers/tty/tty_ldisc.c:552 tiocsetd drivers/tty/tty_io.c:2433 [inline] tty_ioctl+0xe20/0x15d0 drivers/tty/tty_io.c:2714 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:870 [inline] __se_sys_ioctl fs/ioctl.c:856 [inline] __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:856 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd Memory state around the buggy address: ffff88801c995700: fb fb fb fb fb fb fc fc fc fc fc fc fc fc fc fc ffff88801c995780: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88801c995800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fc fc ^ ffff88801c995880: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb ffff88801c995900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================