Hello, syzbot found the following issue on: HEAD commit: fcc79e1714e8 Merge tag 'net-next-6.13' of git://git.kernel.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=14f006e8580000 kernel config: https://syzkaller.appspot.com/x/.config?x=275de99a754927af dashboard link: https://syzkaller.appspot.com/bug?extid=ee903ccb508953ef5998 compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40 Unfortunately, I don't have any reproducer for this issue yet. Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/ccf5d85f3d45/disk-fcc79e17.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/ad2e5fc1309d/vmlinux-fcc79e17.xz kernel image: https://storage.googleapis.com/syzbot-assets/9aa637b02b96/bzImage-fcc79e17.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+ee903ccb508953ef5998@xxxxxxxxxxxxxxxxxxxxxxxxx ================================================================== BUG: KASAN: slab-use-after-free in l2cap_disconn_ind+0x79/0xc0 net/bluetooth/l2cap_core.c:7289 Read of size 1 at addr ffff88804b259ab0 by task kworker/u9:3/5854 CPU: 1 UID: 0 PID: 5854 Comm: kworker/u9:3 Not tainted 6.12.0-syzkaller-05480-gfcc79e1714e8 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/30/2024 Workqueue: hci2 hci_conn_timeout Call Trace: <TASK> __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 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 l2cap_disconn_ind+0x79/0xc0 net/bluetooth/l2cap_core.c:7289 hci_proto_disconn_ind include/net/bluetooth/hci_core.h:2011 [inline] hci_conn_timeout+0xd9/0x290 net/bluetooth/hci_conn.c:579 process_one_work kernel/workqueue.c:3229 [inline] process_scheduled_works+0xa63/0x1850 kernel/workqueue.c:3310 worker_thread+0x870/0xd30 kernel/workqueue.c:3391 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 </TASK> Allocated by task 9901: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:377 [inline] __kasan_kmalloc+0x98/0xb0 mm/kasan/common.c:394 kasan_kmalloc include/linux/kasan.h:257 [inline] __kmalloc_cache_noprof+0x19c/0x2c0 mm/slub.c:4295 kmalloc_noprof include/linux/slab.h:879 [inline] kzalloc_noprof include/linux/slab.h:1015 [inline] l2cap_conn_add+0xa9/0x8e0 net/bluetooth/l2cap_core.c:6860 l2cap_chan_connect+0x623/0xeb0 net/bluetooth/l2cap_core.c:7051 bt_6lowpan_connect net/bluetooth/6lowpan.c:894 [inline] lowpan_control_write+0x568/0x850 net/bluetooth/6lowpan.c:1129 full_proxy_write+0x111/0x1b0 fs/debugfs/file.c:356 vfs_write+0x2a3/0xd30 fs/read_write.c:677 ksys_write+0x18f/0x2b0 fs/read_write.c:731 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 9032: 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 mm/kasan/common.c:247 [inline] __kasan_slab_free+0x59/0x70 mm/kasan/common.c:264 kasan_slab_free include/linux/kasan.h:230 [inline] slab_free_hook mm/slub.c:2342 [inline] slab_free mm/slub.c:4579 [inline] kfree+0x1a0/0x440 mm/slub.c:4727 hci_disconn_cfm include/net/bluetooth/hci_core.h:2050 [inline] hci_conn_hash_flush+0xff/0x240 net/bluetooth/hci_conn.c:2698 hci_dev_close_sync+0xa42/0x11c0 net/bluetooth/hci_sync.c:5212 hci_dev_do_close net/bluetooth/hci_core.c:483 [inline] hci_unregister_dev+0x20b/0x510 net/bluetooth/hci_core.c:2698 vhci_release+0x80/0xd0 drivers/bluetooth/hci_vhci.c:664 __fput+0x23c/0xa50 fs/file_table.c:450 task_work_run+0x24f/0x310 kernel/task_work.c:239 exit_task_work include/linux/task_work.h:43 [inline] do_exit+0xa2f/0x28e0 kernel/exit.c:938 do_group_exit+0x207/0x2c0 kernel/exit.c:1087 __do_sys_exit_group kernel/exit.c:1098 [inline] __se_sys_exit_group kernel/exit.c:1096 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1096 x64_sys_call+0x26a8/0x26b0 arch/x86/include/generated/asm/syscalls_64.h:232 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff88804b259800 which belongs to the cache kmalloc-1k of size 1024 The buggy address is located 688 bytes inside of freed 1024-byte region [ffff88804b259800, ffff88804b259c00) The buggy address belongs to the physical page: page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x4b258 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 ksm flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000040 ffff88801ac41dc0 ffffea000089c000 dead000000000003 raw: 0000000000000000 0000000000100010 00000001f5000000 0000000000000000 head: 00fff00000000040 ffff88801ac41dc0 ffffea000089c000 dead000000000003 head: 0000000000000000 0000000000100010 00000001f5000000 0000000000000000 head: 00fff00000000003 ffffea00012c9601 ffffffffffffffff 0000000000000000 head: 0000000000000008 0000000000000000 00000000ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Unmovable, gfp_mask 0xf2820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_MEMALLOC), pid 7745, tgid 7745 (kworker/u8:13), ts 138751649852, free_ts 138600893157 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1f3/0x230 mm/page_alloc.c:1556 prep_new_page mm/page_alloc.c:1564 [inline] get_page_from_freelist+0x3649/0x3790 mm/page_alloc.c:3474 __alloc_pages_noprof+0x292/0x710 mm/page_alloc.c:4751 alloc_pages_mpol_noprof+0x3e8/0x680 mm/mempolicy.c:2265 alloc_slab_page+0x6a/0x140 mm/slub.c:2412 allocate_slab+0x5a/0x2f0 mm/slub.c:2578 new_slab mm/slub.c:2631 [inline] ___slab_alloc+0xcd1/0x14b0 mm/slub.c:3818 __slab_alloc+0x58/0xa0 mm/slub.c:3908 __slab_alloc_node mm/slub.c:3961 [inline] slab_alloc_node mm/slub.c:4122 [inline] __do_kmalloc_node mm/slub.c:4263 [inline] __kmalloc_node_track_caller_noprof+0x281/0x440 mm/slub.c:4283 kmalloc_reserve+0x111/0x2a0 net/core/skbuff.c:609 __alloc_skb+0x1f3/0x440 net/core/skbuff.c:678 __netdev_alloc_skb+0x103/0xa00 net/core/skbuff.c:742 __netdev_alloc_skb_ip_align include/linux/skbuff.h:3422 [inline] netdev_alloc_skb_ip_align include/linux/skbuff.h:3432 [inline] batadv_iv_ogm_aggregate_new net/batman-adv/bat_iv_ogm.c:558 [inline] batadv_iv_ogm_queue_add+0x6bc/0xc10 net/batman-adv/bat_iv_ogm.c:670 batadv_iv_ogm_schedule_buff net/batman-adv/bat_iv_ogm.c:849 [inline] batadv_iv_ogm_schedule+0xc53/0x10a0 net/batman-adv/bat_iv_ogm.c:868 batadv_iv_send_outstanding_bat_ogm_packet+0x6fe/0x810 net/batman-adv/bat_iv_ogm.c:1712 process_one_work kernel/workqueue.c:3229 [inline] process_scheduled_works+0xa63/0x1850 kernel/workqueue.c:3310 page last free pid 9133 tgid 9133 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1127 [inline] free_unref_page+0xdf9/0x1140 mm/page_alloc.c:2657 discard_slab mm/slub.c:2677 [inline] __put_partials+0xeb/0x130 mm/slub.c:3145 put_cpu_partial+0x17c/0x250 mm/slub.c:3220 __slab_free+0x2ea/0x3d0 mm/slub.c:4449 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x9a/0x140 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x14f/0x170 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x23/0x80 mm/kasan/common.c:329 kasan_slab_alloc include/linux/kasan.h:247 [inline] slab_post_alloc_hook mm/slub.c:4085 [inline] slab_alloc_node mm/slub.c:4134 [inline] kmem_cache_alloc_noprof+0x135/0x2a0 mm/slub.c:4141 getname_flags+0xb7/0x540 fs/namei.c:139 do_sys_openat2+0xd2/0x1d0 fs/open.c:1392 do_sys_open fs/open.c:1413 [inline] __do_sys_openat fs/open.c:1429 [inline] __se_sys_openat fs/open.c:1424 [inline] __x64_sys_openat+0x247/0x2a0 fs/open.c:1424 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f Memory state around the buggy address: ffff88804b259980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88804b259a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88804b259a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88804b259b00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88804b259b80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== --- This report is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at syzkaller@xxxxxxxxxxxxxxxx. syzbot will keep track of this issue. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot. If the report is already addressed, let syzbot know by replying with: #syz fix: exact-commit-title If you want to overwrite report's subsystems, reply with: #syz set subsystems: new-subsystem (See the list of subsystem names on the web dashboard) If the report is a duplicate of another one, reply with: #syz dup: exact-subject-of-another-report If you want to undo deduplication, reply with: #syz undup
