================================================================== BUG: KASAN: use-after-free in hci_uart_write_work+0x4ad/0x7b0 drivers/bluetooth/hci_ldisc.c:165 Read of size 8 at addr ffff8881436e24a8 by task kworker/1:3/344 CPU: 1 PID: 344 Comm: kworker/1:3 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Workqueue: events hci_uart_write_work Call Trace: __dump_stack+0x21/0x24 lib/dump_stack.c:88 dump_stack_lvl+0xee/0x150 lib/dump_stack.c:106 print_address_description+0x71/0x1e0 mm/kasan/report.c:316 print_report+0x4a/0x60 mm/kasan/report.c:418 kasan_report+0x122/0x150 mm/kasan/report.c:522 __asan_report_load8_noabort+0x14/0x20 mm/kasan/report_generic.c:351 hci_uart_write_work+0x4ad/0x7b0 drivers/bluetooth/hci_ldisc.c:165 process_one_work+0x71f/0xc40 kernel/workqueue.c:2302 worker_thread+0xa29/0x11f0 kernel/workqueue.c:2449 kthread+0x281/0x320 kernel/kthread.c:386 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Allocated by task 45: kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:52 kasan_save_alloc_info+0x25/0x30 mm/kasan/generic.c:505 __kasan_slab_alloc+0x72/0x80 mm/kasan/common.c:333 kasan_slab_alloc include/linux/kasan.h:202 [inline] slab_post_alloc_hook+0x4f/0x2d0 mm/slab.h:768 slab_alloc_node mm/slub.c:3421 [inline] kmem_cache_alloc_node+0x181/0x340 mm/slub.c:3468 __alloc_skb+0xea/0x4b0 net/core/skbuff.c:508 alloc_skb include/linux/skbuff.h:1290 [inline] bt_skb_alloc include/net/bluetooth/bluetooth.h:473 [inline] hci_cmd_sync_alloc net/bluetooth/hci_sync.c:55 [inline] hci_cmd_sync_add net/bluetooth/hci_sync.c:96 [inline] __hci_cmd_sync_sk+0x1d1/0xcf0 net/bluetooth/hci_sync.c:158 __hci_cmd_sync_status_sk net/bluetooth/hci_sync.c:253 [inline] __hci_cmd_sync_status net/bluetooth/hci_sync.c:277 [inline] hci_read_local_features_sync net/bluetooth/hci_sync.c:3621 [inline] hci_init_stage_sync net/bluetooth/hci_sync.c:3532 [inline] hci_init1_sync net/bluetooth/hci_sync.c:3716 [inline] hci_init_sync net/bluetooth/hci_sync.c:4798 [inline] hci_dev_init_sync net/bluetooth/hci_sync.c:4989 [inline] hci_dev_open_sync+0x13a7/0x3260 net/bluetooth/hci_sync.c:5069 hci_dev_do_open net/bluetooth/hci_core.c:439 [inline] hci_power_on+0x195/0x5c0 net/bluetooth/hci_core.c:945 process_one_work+0x71f/0xc40 kernel/workqueue.c:2302 worker_thread+0xa29/0x11f0 kernel/workqueue.c:2449 kthread+0x281/0x320 kernel/kthread.c:386 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 The buggy address belongs to the object at ffff8881436e23c0 which belongs to the cache skbuff_head_cache of size 256 The buggy address is located 232 bytes inside of 256-byte region [ffff8881436e23c0, ffff8881436e24c0) The buggy address belongs to the physical page: page:ffffea00050db880 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1436e2 flags: 0x4000000000000200(slab|zone=1) raw: 4000000000000200 ffffea0004571780 dead000000000004 ffff888100b9d200 raw: 0000000000000000 00000000800c000c 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 0x112cc0(GFP_USER|__GFP_NOWARN|__GFP_NORETRY), pid 2035, tgid 2035 (udevd), ts 178615994283, free_ts 178608010867 set_page_owner include/linux/page_owner.h:33 [inline] post_alloc_hook+0x1f5/0x210 mm/page_alloc.c:2643 prep_new_page+0x1c/0x110 mm/page_alloc.c:2650 get_page_from_freelist+0x2c7b/0x2cf0 mm/page_alloc.c:4554 __alloc_pages+0x1c3/0x450 mm/page_alloc.c:5868 alloc_slab_page+0x6e/0xf0 include/linux/gfp.h:-1 allocate_slab mm/slub.c:1962 [inline] new_slab+0x98/0x3d0 mm/slub.c:2015 ___slab_alloc+0x6f6/0xb50 mm/slub.c:3203 __slab_alloc+0x5e/0xa0 mm/slub.c:3302 slab_alloc_node mm/slub.c:3387 [inline] kmem_cache_alloc_node+0x1c2/0x340 mm/slub.c:3468 __alloc_skb+0xea/0x4b0 net/core/skbuff.c:508 alloc_skb include/linux/skbuff.h:1290 [inline] netlink_alloc_large_skb net/netlink/af_netlink.c:1183 [inline] netlink_sendmsg+0x626/0xbc0 net/netlink/af_netlink.c:1848 sock_sendmsg_nosec net/socket.c:716 [inline] __sock_sendmsg net/socket.c:728 [inline] ____sys_sendmsg+0x5a9/0x990 net/socket.c:2509 ___sys_sendmsg+0x21c/0x290 net/socket.c:2563 __sys_sendmsg net/socket.c:2592 [inline] __do_sys_sendmsg net/socket.c:2601 [inline] __se_sys_sendmsg net/socket.c:2599 [inline] __x64_sys_sendmsg+0x1f0/0x2c0 net/socket.c:2599 x64_sys_call+0x171/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:47 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81 page last free stack trace: reset_page_owner include/linux/page_owner.h:26 [inline] free_pages_prepare mm/page_alloc.c:1551 [inline] free_pcp_prepare mm/page_alloc.c:1625 [inline] free_unref_page_prepare+0x742/0x750 mm/page_alloc.c:3589 free_unref_page+0x8f/0x530 mm/page_alloc.c:3687 free_the_page mm/page_alloc.c:836 [inline] __free_pages+0x67/0x100 mm/page_alloc.c:5957 free_pages+0x82/0x90 mm/page_alloc.c:5968 tlb_batch_list_free mm/mmu_gather.c:75 [inline] tlb_finish_mmu+0x2ba/0x370 mm/mmu_gather.c:364 exit_mmap+0x3dd/0xb60 mm/mmap.c:3378 __mmput+0x93/0x320 kernel/fork.c:1300 mmput+0x4b/0x150 kernel/fork.c:1323 exit_mm kernel/exit.c:568 [inline] do_exit+0x981/0x2650 kernel/exit.c:873 do_group_exit+0x210/0x2d0 kernel/exit.c:1028 get_signal+0x13b5/0x1520 kernel/signal.c:2889 arch_do_signal_or_restart+0xb0/0x1030 arch/x86/kernel/signal.c:871 exit_to_user_mode_loop+0x7a/0xb0 kernel/entry/common.c:174 exit_to_user_mode_prepare+0x5a/0xa0 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline] syscall_exit_to_user_mode+0x1a/0x30 kernel/entry/common.c:303 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:87 Memory state around the buggy address: ffff8881436e2380: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb ffff8881436e2400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8881436e2480: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ^ ffff8881436e2500: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8881436e2580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================