================================================================== BUG: KASAN: slab-use-after-free in l2cap_disconn_ind+0x79/0xc0 net/bluetooth/l2cap_core.c:7315 Read of size 1 at addr ffff88807bb0fab0 by task kworker/u9:1/12569 CPU: 0 UID: 0 PID: 12569 Comm: kworker/u9:1 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Workqueue: hci1 hci_conn_timeout Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0xca/0x240 mm/kasan/report.c:482 kasan_report+0x118/0x150 mm/kasan/report.c:595 l2cap_disconn_ind+0x79/0xc0 net/bluetooth/l2cap_core.c:7315 hci_proto_disconn_ind include/net/bluetooth/hci_core.h:2082 [inline] hci_conn_timeout+0xdd/0x290 net/bluetooth/hci_conn.c:579 process_one_work kernel/workqueue.c:3263 [inline] process_scheduled_works+0xade/0x17b0 kernel/workqueue.c:3346 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427 kthread+0x70e/0x8a0 kernel/kthread.c:463 ret_from_fork+0x436/0x7d0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Allocated by task 31430: kasan_save_stack mm/kasan/common.c:56 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:77 poison_kmalloc_redzone mm/kasan/common.c:400 [inline] __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:417 kasan_kmalloc include/linux/kasan.h:262 [inline] __kmalloc_cache_noprof+0x3d5/0x6f0 mm/slub.c:5724 kmalloc_noprof include/linux/slab.h:957 [inline] kzalloc_noprof include/linux/slab.h:1094 [inline] l2cap_conn_add+0xaa/0x8d0 net/bluetooth/l2cap_core.c:6886 l2cap_chan_connect+0x6c8/0xe30 net/bluetooth/l2cap_core.c:7077 bt_6lowpan_connect net/bluetooth/6lowpan.c:900 [inline] lowpan_control_write+0x421/0x6c0 net/bluetooth/6lowpan.c:1135 full_proxy_write+0x127/0x1f0 fs/debugfs/file.c:388 vfs_write+0x27b/0xb30 fs/read_write.c:684 ksys_write+0x145/0x250 fs/read_write.c:738 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline] __do_fast_syscall_32+0xb6/0x2b0 arch/x86/entry/syscall_32.c:306 do_fast_syscall_32+0x34/0x80 arch/x86/entry/syscall_32.c:331 entry_SYSENTER_compat_after_hwframe+0x84/0x8e Freed by task 31458: kasan_save_stack mm/kasan/common.c:56 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:77 __kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:587 kasan_save_free_info mm/kasan/kasan.h:406 [inline] poison_slab_object mm/kasan/common.c:252 [inline] __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:284 kasan_slab_free include/linux/kasan.h:234 [inline] slab_free_hook mm/slub.c:2514 [inline] slab_free mm/slub.c:6566 [inline] kfree+0x19a/0x6d0 mm/slub.c:6773 l2cap_connect_cfm+0x11d/0x1040 net/bluetooth/l2cap_core.c:7259 hci_connect_cfm include/net/bluetooth/hci_core.h:2106 [inline] hci_conn_failed+0x1ce/0x310 net/bluetooth/hci_conn.c:1312 hci_abort_conn_sync+0x658/0xe30 net/bluetooth/hci_sync.c:5698 hci_disconnect_all_sync+0x1b5/0x350 net/bluetooth/hci_sync.c:5721 hci_suspend_sync+0x3fc/0xc60 net/bluetooth/hci_sync.c:6197 hci_suspend_dev+0x28d/0x4d0 net/bluetooth/hci_core.c:2849 hci_suspend_notifier+0xf2/0x290 net/bluetooth/hci_core.c:2420 notifier_call_chain+0x1b6/0x3e0 kernel/notifier.c:85 notifier_call_chain_robust kernel/notifier.c:120 [inline] blocking_notifier_call_chain_robust+0x85/0x100 kernel/notifier.c:345 pm_notifier_call_chain_robust+0x2c/0x60 kernel/power/main.c:103 snapshot_open+0x19c/0x280 kernel/power/user.c:77 misc_open+0x2bc/0x330 drivers/char/misc.c:161 chrdev_open+0x4cc/0x5e0 fs/char_dev.c:414 do_dentry_open+0x953/0x13f0 fs/open.c:965 vfs_open+0x3b/0x340 fs/open.c:1097 do_open fs/namei.c:3975 [inline] path_openat+0x2ee5/0x3830 fs/namei.c:4134 do_filp_open+0x1fa/0x410 fs/namei.c:4161 do_sys_openat2+0x121/0x1c0 fs/open.c:1437 do_sys_open fs/open.c:1452 [inline] __do_compat_sys_openat fs/open.c:1514 [inline] __se_compat_sys_openat fs/open.c:1512 [inline] __ia32_compat_sys_openat+0x131/0x160 fs/open.c:1512 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline] __do_fast_syscall_32+0xb6/0x2b0 arch/x86/entry/syscall_32.c:306 do_fast_syscall_32+0x34/0x80 arch/x86/entry/syscall_32.c:331 entry_SYSENTER_compat_after_hwframe+0x84/0x8e The buggy address belongs to the object at ffff88807bb0f800 which belongs to the cache kmalloc-1k of size 1024 The buggy address is located 688 bytes inside of freed 1024-byte region [ffff88807bb0f800, ffff88807bb0fc00) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x7bb08 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000040 ffff88813fe26dc0 dead000000000100 dead000000000122 raw: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000 head: 00fff00000000040 ffff88813fe26dc0 dead000000000100 dead000000000122 head: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000 head: 00fff00000000003 ffffea0001eec201 00000000ffffffff 00000000ffffffff head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000008 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Unmovable, gfp_mask 0x52820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 13, tgid 13 (kworker/u8:1), ts 195390710820, free_ts 195384216811 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x240/0x2a0 mm/page_alloc.c:1850 prep_new_page mm/page_alloc.c:1858 [inline] get_page_from_freelist+0x2365/0x2440 mm/page_alloc.c:3884 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5183 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2416 alloc_slab_page mm/slub.c:3030 [inline] allocate_slab+0x96/0x3a0 mm/slub.c:3203 new_slab mm/slub.c:3257 [inline] ___slab_alloc+0xe94/0x1920 mm/slub.c:4627 __slab_alloc+0x65/0x100 mm/slub.c:4746 __slab_alloc_node mm/slub.c:4822 [inline] slab_alloc_node mm/slub.c:5233 [inline] __do_kmalloc_node mm/slub.c:5602 [inline] __kmalloc_noprof+0x471/0x7f0 mm/slub.c:5615 kmalloc_noprof include/linux/slab.h:961 [inline] kzalloc_noprof include/linux/slab.h:1094 [inline] ieee802_11_parse_elems_full+0x152/0x2ab0 net/mac80211/parse.c:1011 ieee802_11_parse_elems_crc net/mac80211/ieee80211_i.h:2470 [inline] ieee802_11_parse_elems net/mac80211/ieee80211_i.h:2477 [inline] ieee80211_inform_bss+0x10c/0x10a0 net/mac80211/scan.c:79 rdev_inform_bss net/wireless/rdev-ops.h:418 [inline] cfg80211_inform_single_bss_data+0xd02/0x1ac0 net/wireless/scan.c:2385 cfg80211_inform_bss_data+0x203/0x3b40 net/wireless/scan.c:3240 cfg80211_inform_bss_frame_data+0x3d7/0x730 net/wireless/scan.c:3331 ieee80211_bss_info_update+0x749/0x9e0 net/mac80211/scan.c:226 ieee80211_rx_bss_info net/mac80211/ibss.c:1094 [inline] ieee80211_rx_mgmt_probe_beacon net/mac80211/ibss.c:1573 [inline] ieee80211_ibss_rx_queued_mgmt+0xa4e/0x2af0 net/mac80211/ibss.c:1600 ieee80211_iface_process_skb net/mac80211/iface.c:1694 [inline] ieee80211_iface_work+0x85f/0x12d0 net/mac80211/iface.c:1748 page last free pid 6321 tgid 6321 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1394 [inline] __free_frozen_pages+0xbc4/0xd30 mm/page_alloc.c:2906 discard_slab mm/slub.c:3301 [inline] __put_partials+0x146/0x170 mm/slub.c:3848 put_cpu_partial+0x1f2/0x2e0 mm/slub.c:3923 __slab_free+0x2b9/0x390 mm/slub.c:5882 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x97/0x140 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:352 kasan_slab_alloc include/linux/kasan.h:252 [inline] slab_post_alloc_hook mm/slub.c:4946 [inline] slab_alloc_node mm/slub.c:5245 [inline] kmem_cache_alloc_noprof+0x367/0x6e0 mm/slub.c:5252 getname_flags+0xb8/0x540 fs/namei.c:146 getname include/linux/fs.h:2921 [inline] do_sys_openat2+0xbc/0x1c0 fs/open.c:1431 do_sys_open fs/open.c:1452 [inline] __do_sys_openat fs/open.c:1468 [inline] __se_sys_openat fs/open.c:1463 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1463 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Memory state around the buggy address: ffff88807bb0f980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88807bb0fa00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88807bb0fa80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88807bb0fb00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88807bb0fb80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================