================================================================== BUG: KASAN: slab-use-after-free in hci_cmd_timeout+0x1d9/0x1e0 net/bluetooth/hci_core.c:1526 Read of size 2 at addr ffff888063de4cb8 by task kworker/u9:2/5071 CPU: 0 PID: 5071 Comm: kworker/u9:2 Not tainted 6.8.0-syzkaller-08951-gfe46a7dd189e #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 Workqueue: hci0 hci_cmd_timeout Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114 print_address_description mm/kasan/report.c:377 [inline] print_report+0x169/0x550 mm/kasan/report.c:488 kasan_report+0x143/0x180 mm/kasan/report.c:601 hci_cmd_timeout+0x1d9/0x1e0 net/bluetooth/hci_core.c:1526 process_one_work kernel/workqueue.c:3254 [inline] process_scheduled_works+0xa00/0x1770 kernel/workqueue.c:3335 worker_thread+0x86d/0xd70 kernel/workqueue.c:3416 kthread+0x2f0/0x390 kernel/kthread.c:388 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:243 Allocated by task 5071: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 unpoison_slab_object mm/kasan/common.c:312 [inline] __kasan_slab_alloc+0x66/0x80 mm/kasan/common.c:338 kasan_slab_alloc include/linux/kasan.h:201 [inline] slab_post_alloc_hook mm/slub.c:3798 [inline] slab_alloc_node mm/slub.c:3845 [inline] kmem_cache_alloc+0x174/0x340 mm/slub.c:3852 skb_clone+0x20c/0x390 net/core/skbuff.c:2063 hci_send_cmd_sync net/bluetooth/hci_core.c:4220 [inline] hci_cmd_work+0x29c/0x660 net/bluetooth/hci_core.c:4240 process_one_work kernel/workqueue.c:3254 [inline] process_scheduled_works+0xa00/0x1770 kernel/workqueue.c:3335 worker_thread+0x86d/0xd70 kernel/workqueue.c:3416 kthread+0x2f0/0x390 kernel/kthread.c:388 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:243 Freed by task 7810: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:579 poison_slab_object+0xa6/0xe0 mm/kasan/common.c:240 __kasan_slab_free+0x37/0x60 mm/kasan/common.c:256 kasan_slab_free include/linux/kasan.h:184 [inline] slab_free_hook mm/slub.c:2106 [inline] slab_free mm/slub.c:4280 [inline] kmem_cache_free+0x102/0x2b0 mm/slub.c:4344 kfree_skb include/linux/skbuff.h:1267 [inline] __hci_req_sync+0x62f/0x950 net/bluetooth/hci_request.c:182 hci_req_sync+0xa9/0xd0 net/bluetooth/hci_request.c:204 hci_inquiry+0x44b/0x870 net/bluetooth/hci_core.c:425 sock_do_ioctl+0x158/0x460 net/socket.c:1222 sock_ioctl+0x629/0x8e0 net/socket.c:1341 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:904 [inline] __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:890 do_syscall_64+0xfb/0x240 entry_SYSCALL_64_after_hwframe+0x6d/0x75 The buggy address belongs to the object at ffff888063de4c80 which belongs to the cache skbuff_head_cache of size 240 The buggy address is located 56 bytes inside of freed 240-byte region [ffff888063de4c80, ffff888063de4d70) The buggy address belongs to the physical page: page:ffffea00018f7900 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x63de4 anon flags: 0xfff00000000800(slab|node=0|zone=1|lastcpupid=0x7ff) page_type: 0xffffffff() raw: 00fff00000000800 ffff888018a96780 ffffea0000b70100 dead000000000005 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 0x12cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY), pid 5067, tgid 5067 (syz-executor.4), ts 70806522439, free_ts 19279001901 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x1ea/0x210 mm/page_alloc.c:1533 prep_new_page mm/page_alloc.c:1540 [inline] get_page_from_freelist+0x33ea/0x3580 mm/page_alloc.c:3311 __alloc_pages+0x256/0x680 mm/page_alloc.c:4569 __alloc_pages_node include/linux/gfp.h:238 [inline] alloc_pages_node include/linux/gfp.h:261 [inline] alloc_slab_page+0x5f/0x160 mm/slub.c:2175 allocate_slab mm/slub.c:2338 [inline] new_slab+0x84/0x2f0 mm/slub.c:2391 ___slab_alloc+0xc73/0x1260 mm/slub.c:3525 __slab_alloc mm/slub.c:3610 [inline] __slab_alloc_node mm/slub.c:3663 [inline] slab_alloc_node mm/slub.c:3835 [inline] kmem_cache_alloc_node+0x24a/0x380 mm/slub.c:3888 __alloc_skb+0x1c3/0x440 net/core/skbuff.c:658 netlink_sendmsg+0x637/0xcb0 net/netlink/af_netlink.c:1880 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg+0x221/0x270 net/socket.c:745 __sys_sendto+0x3a4/0x4f0 net/socket.c:2191 __do_sys_sendto net/socket.c:2203 [inline] __se_sys_sendto net/socket.c:2199 [inline] __x64_sys_sendto+0xde/0x100 net/socket.c:2199 do_syscall_64+0xfb/0x240 entry_SYSCALL_64_after_hwframe+0x6d/0x75 page last free pid 1 tgid 1 stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1140 [inline] free_unref_page_prepare+0x95d/0xa80 mm/page_alloc.c:2346 free_unref_page+0x37/0x3f0 mm/page_alloc.c:2486 free_contig_range+0x9e/0x160 mm/page_alloc.c:6547 destroy_args+0x8a/0x890 mm/debug_vm_pgtable.c:1036 debug_vm_pgtable+0x4be/0x550 mm/debug_vm_pgtable.c:1416 do_one_initcall+0x238/0x830 init/main.c:1241 do_initcall_level+0x157/0x210 init/main.c:1303 do_initcalls+0x3f/0x80 init/main.c:1319 kernel_init_freeable+0x435/0x5d0 init/main.c:1550 kernel_init+0x1d/0x2a0 init/main.c:1439 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:243 Memory state around the buggy address: ffff888063de4b80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888063de4c00: fb fb fb fb fb fb fc fc fc fc fc fc fc fc fc fc >ffff888063de4c80: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888063de4d00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fc fc ffff888063de4d80: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb 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