================================================================== BUG: KASAN: slab-out-of-bounds in force_devcd_write+0x31f/0x350 drivers/bluetooth/hci_vhci.c:327 Read of size 8 at addr ffff88807a41a800 by task syz.2.1257/11815 CPU: 1 UID: 0 PID: 11815 Comm: syz.2.1257 Tainted: G U 6.14.0-rc1-syzkaller-00081-gbb066fe812d6 #0 Tainted: [U]=USER Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0xc3/0x620 mm/kasan/report.c:489 kasan_report+0xd9/0x110 mm/kasan/report.c:602 force_devcd_write+0x31f/0x350 drivers/bluetooth/hci_vhci.c:327 full_proxy_write+0x13c/0x200 fs/debugfs/file.c:398 vfs_write+0x24c/0x1150 fs/read_write.c:677 ksys_write+0x12b/0x250 fs/read_write.c:731 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f15f778cde9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f15f863d038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f15f79a5fa0 RCX: 00007f15f778cde9 RDX: 000000000000000e RSI: 0000000000000000 RDI: 0000000000000006 RBP: 00007f15f780e2a0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f15f79a5fa0 R15: 00007ffdb98ac778 Allocated by task 10399: kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:377 [inline] __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:394 kasan_kmalloc include/linux/kasan.h:260 [inline] __do_kmalloc_node mm/slub.c:4294 [inline] __kmalloc_node_noprof+0x21f/0x520 mm/slub.c:4300 __kvmalloc_node_noprof+0xad/0x1a0 mm/util.c:662 kvmalloc_array_node_noprof include/linux/slab.h:1063 [inline] alloc_fdtable+0xee/0x2b0 fs/file.c:199 dup_fd+0x92b/0xca0 fs/file.c:400 copy_files kernel/fork.c:1806 [inline] copy_process+0x2217/0x6f20 kernel/fork.c:2391 kernel_clone+0xfd/0x960 kernel/fork.c:2815 __do_sys_clone+0xba/0x100 kernel/fork.c:2958 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 11677: kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:576 poison_slab_object mm/kasan/common.c:247 [inline] __kasan_slab_free+0x51/0x70 mm/kasan/common.c:264 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2353 [inline] slab_free mm/slub.c:4609 [inline] kfree+0x2c4/0x4d0 mm/slub.c:4757 kvfree+0x47/0x50 mm/util.c:705 __free_fdtable fs/file.c:100 [inline] put_files_struct fs/file.c:485 [inline] put_files_struct+0x270/0x370 fs/file.c:478 exit_files+0x82/0xb0 fs/file.c:498 do_exit+0xaa4/0x2d70 kernel/exit.c:933 do_group_exit+0xd3/0x2a0 kernel/exit.c:1087 get_signal+0x2576/0x2610 kernel/signal.c:3036 arch_do_signal_or_restart+0x90/0x7e0 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0x150/0x2a0 kernel/entry/common.c:218 do_syscall_64+0xda/0x250 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff88807a41a000 which belongs to the cache kmalloc-cg-2k of size 2048 The buggy address is located 0 bytes to the right of allocated 2048-byte region [ffff88807a41a000, ffff88807a41a800) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x7a418 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 memcg:ffff88803231ee81 flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000040 ffff88801b04f3c0 dead000000000100 dead000000000122 raw: 0000000000000000 0000000000080008 00000000f5000000 ffff88803231ee81 head: 00fff00000000040 ffff88801b04f3c0 dead000000000100 dead000000000122 head: 0000000000000000 0000000000080008 00000000f5000000 ffff88803231ee81 head: 00fff00000000003 ffffea0001e90601 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 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 11303, tgid 11299 (syz.5.1140), ts 505792879602, free_ts 505706237675 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x181/0x1b0 mm/page_alloc.c:1551 prep_new_page mm/page_alloc.c:1559 [inline] get_page_from_freelist+0xfce/0x2f80 mm/page_alloc.c:3477 __alloc_frozen_pages_noprof+0x221/0x2470 mm/page_alloc.c:4739 alloc_pages_mpol+0x1fc/0x540 mm/mempolicy.c:2270 alloc_slab_page mm/slub.c:2423 [inline] allocate_slab mm/slub.c:2587 [inline] new_slab+0x23d/0x330 mm/slub.c:2640 ___slab_alloc+0xbfa/0x1600 mm/slub.c:3826 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3916 __slab_alloc_node mm/slub.c:3991 [inline] slab_alloc_node mm/slub.c:4152 [inline] __kmalloc_cache_noprof+0xf6/0x420 mm/slub.c:4320 kmalloc_noprof include/linux/slab.h:901 [inline] kzalloc_noprof include/linux/slab.h:1037 [inline] ipv6_add_dev+0xfe/0x13e0 net/ipv6/addrconf.c:384 addrconf_notify+0x53e/0x19c0 net/ipv6/addrconf.c:3646 notifier_call_chain+0xb7/0x410 kernel/notifier.c:85 call_netdevice_notifiers_info+0xbe/0x140 net/core/dev.c:2141 call_netdevice_notifiers_extack net/core/dev.c:2179 [inline] call_netdevice_notifiers net/core/dev.c:2193 [inline] register_netdevice+0x174a/0x1e50 net/core/dev.c:10896 __ip_tunnel_create+0x37b/0x4c0 net/ipv4/ip_tunnel.c:267 ip_tunnel_init_net+0x1c2/0x6e0 net/ipv4/ip_tunnel.c:1160 ops_init+0x1df/0x5f0 net/core/net_namespace.c:138 page last free pid 11303 tgid 11299 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1127 [inline] free_frozen_pages+0x6db/0xfb0 mm/page_alloc.c:2660 __put_partials+0x14c/0x170 mm/slub.c:3153 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x4e/0x120 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x195/0x1e0 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:329 kasan_slab_alloc include/linux/kasan.h:250 [inline] slab_post_alloc_hook mm/slub.c:4115 [inline] slab_alloc_node mm/slub.c:4164 [inline] kmem_cache_alloc_noprof+0x1c8/0x3b0 mm/slub.c:4171 __proc_create+0x2c3/0x8b0 fs/proc/generic.c:427 _proc_mkdir+0xbb/0x200 fs/proc/generic.c:491 proc_net_mkdir include/linux/proc_fs.h:232 [inline] sctp_proc_init+0x59/0x270 net/sctp/proc.c:378 sctp_defaults_init+0x74a/0xd80 net/sctp/protocol.c:1427 ops_init+0x1df/0x5f0 net/core/net_namespace.c:138 setup_net+0x21f/0x860 net/core/net_namespace.c:362 copy_net_ns+0x2b4/0x6c0 net/core/net_namespace.c:516 create_new_namespaces+0x3ea/0xad0 kernel/nsproxy.c:110 unshare_nsproxy_namespaces+0xc0/0x1f0 kernel/nsproxy.c:228 ksys_unshare+0x45d/0xa40 kernel/fork.c:3342 Memory state around the buggy address: ffff88807a41a700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88807a41a780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88807a41a800: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff88807a41a880: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88807a41a900: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================