================================================================== BUG: KASAN: use-after-free in hci_cmd_timeout+0x24b/0x250 net/bluetooth/hci_core.c:1486 Read of size 2 at addr ffff88814a2d6408 by task kworker/1:2/142 CPU: 1 PID: 142 Comm: kworker/1:2 Not tainted 6.0.0-rc2-next-20220823-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/22/2022 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+0x24b/0x250 net/bluetooth/hci_core.c:1486 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 3499: 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_kmalloc mm/kasan/common.c:516 [inline] ____kasan_kmalloc mm/kasan/common.c:475 [inline] __kasan_kmalloc+0xa9/0xd0 mm/kasan/common.c:525 kmalloc include/linux/slab.h:606 [inline] kzalloc include/linux/slab.h:739 [inline] alloc_bprm+0x51/0x900 fs/exec.c:1516 do_execveat_common+0x22f/0x890 fs/exec.c:1901 do_execve fs/exec.c:2024 [inline] __do_sys_execve fs/exec.c:2100 [inline] __se_sys_execve fs/exec.c:2095 [inline] __x64_sys_execve+0x8f/0xc0 fs/exec.c:2095 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 Freed by task 3625: 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] kfree+0xe2/0x580 mm/slub.c:4562 skb_free_head+0xac/0x110 net/core/skbuff.c:658 skb_release_data+0x5f1/0x870 net/core/skbuff.c:687 skb_release_all net/core/skbuff.c:752 [inline] __kfree_skb net/core/skbuff.c:766 [inline] kfree_skb_reason.part.0+0xdd/0x320 net/core/skbuff.c:788 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:4631 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 ffff88814a2d6400 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 8 bytes inside of 512-byte region [ffff88814a2d6400, ffff88814a2d6600) The buggy address belongs to the physical page: page:ffffea000528b500 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88814a2d7800 pfn:0x14a2d4 head:ffffea000528b500 order:2 compound_mapcount:0 compound_pincount:0 flags: 0x57ff00000010200(slab|head|node=1|zone=2|lastcpupid=0x7ff) raw: 057ff00000010200 ffffea000528b008 ffffea00051e3c08 ffff888011841c80 raw: ffff88814a2d7800 000000000010000c 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 2, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 1, tgid 1 (swapper/0), ts 10958133344, free_ts 0 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:5507 alloc_page_interleave+0x1e/0x200 mm/mempolicy.c:2113 alloc_pages+0x22f/0x270 mm/mempolicy.c:2275 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] slab_alloc mm/slub.c:3251 [inline] __kmalloc+0x32b/0x340 mm/slub.c:4420 kmalloc include/linux/slab.h:611 [inline] kzalloc include/linux/slab.h:739 [inline] new_dir fs/proc/proc_sysctl.c:978 [inline] get_subdir fs/proc/proc_sysctl.c:1022 [inline] __register_sysctl_table+0x9eb/0x10a0 fs/proc/proc_sysctl.c:1373 lowpan_frags_sysctl_register net/ieee802154/6lowpan/reassembly.c:412 [inline] lowpan_net_frag_init+0xb7/0x11a net/ieee802154/6lowpan/reassembly.c:530 lowpan_init_module+0xc/0x8c net/ieee802154/6lowpan/core.c:250 do_one_initcall+0xfe/0x650 init/main.c:1301 do_initcall_level init/main.c:1376 [inline] do_initcalls init/main.c:1392 [inline] do_basic_setup init/main.c:1411 [inline] kernel_init_freeable+0x6b1/0x73a init/main.c:1618 kernel_init+0x1a/0x1d0 init/main.c:1507 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306 page_owner free stack trace missing Memory state around the buggy address: ffff88814a2d6300: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88814a2d6380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff88814a2d6400: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88814a2d6480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88814a2d6500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================