================================================================== BUG: KASAN: stack-out-of-bounds in skb_put_data include/linux/skbuff.h:2800 [inline] BUG: KASAN: stack-out-of-bounds in l2cap_build_cmd net/bluetooth/l2cap_core.c:2999 [inline] BUG: KASAN: stack-out-of-bounds in l2cap_send_cmd+0x9a5/0xc80 net/bluetooth/l2cap_core.c:954 Read of size 26 at addr ffffc90003af7a60 by task kworker/u9:3/5813 CPU: 0 UID: 0 PID: 5813 Comm: kworker/u9:3 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Workqueue: hci2 hci_rx_work Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0x156/0x4c9 mm/kasan/report.c:482 kasan_report+0xdf/0x1e0 mm/kasan/report.c:595 check_region_inline mm/kasan/generic.c:186 [inline] kasan_check_range+0x10f/0x1e0 mm/kasan/generic.c:200 __asan_memcpy+0x23/0x60 mm/kasan/shadow.c:105 skb_put_data include/linux/skbuff.h:2800 [inline] l2cap_build_cmd net/bluetooth/l2cap_core.c:2999 [inline] l2cap_send_cmd+0x9a5/0xc80 net/bluetooth/l2cap_core.c:954 l2cap_ecred_conn_req net/bluetooth/l2cap_core.c:5214 [inline] l2cap_le_sig_cmd net/bluetooth/l2cap_core.c:5516 [inline] l2cap_le_sig_channel net/bluetooth/l2cap_core.c:5574 [inline] l2cap_recv_frame+0x6349/0x9f80 net/bluetooth/l2cap_core.c:6924 l2cap_recv_acldata+0xe60/0x10a0 net/bluetooth/l2cap_core.c:7648 hci_acldata_packet net/bluetooth/hci_core.c:3855 [inline] hci_rx_work+0x537/0xfc0 net/bluetooth/hci_core.c:4082 process_one_work+0xa23/0x19a0 kernel/workqueue.c:3276 process_scheduled_works kernel/workqueue.c:3359 [inline] worker_thread+0x5ef/0xe50 kernel/workqueue.c:3440 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x754/0xd80 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 The buggy address belongs to stack of task kworker/u9:3/5813 and is located at offset 160 in frame: l2cap_recv_frame+0x0/0x9f80 net/bluetooth/l2cap_core.c:1658 This frame has 10 objects: [48, 50) 'rsp' [64, 68) 'rsp' [80, 86) 'rej' [112, 122) 'rsp' [144, 148) 'rsp' [160, 178) 'pdu_u' [224, 264) 'chan' [304, 308) 'rx_func_to_event' [320, 328) 'buf' [352, 364) 'buf' The buggy address belongs to a 8-page vmalloc region starting at 0xffffc90003af0000 allocated at kernel_clone+0xfc/0x9a0 kernel/fork.c:2653 The buggy address belongs to the physical page: page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x7dcb7 flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000000000 0000000000000000 dead000000000122 0000000000000000 raw: 0000000000000000 0000000000000000 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 0x29c2(GFP_NOWAIT|__GFP_HIGHMEM|__GFP_IO|__GFP_FS|__GFP_ZERO), pid 2, tgid 2 (kthreadd), ts 58647591169, free_ts 58574075304 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x153/0x170 mm/page_alloc.c:1889 prep_new_page mm/page_alloc.c:1897 [inline] get_page_from_freelist+0x111d/0x3140 mm/page_alloc.c:3962 __alloc_frozen_pages_noprof+0x27c/0x2ba0 mm/page_alloc.c:5250 __alloc_pages_noprof+0xb/0x1b0 mm/page_alloc.c:5284 __alloc_pages_node_noprof include/linux/gfp.h:289 [inline] alloc_pages_node_noprof include/linux/gfp.h:316 [inline] vm_area_alloc_pages mm/vmalloc.c:3664 [inline] __vmalloc_area_node mm/vmalloc.c:3876 [inline] __vmalloc_node_range_noprof+0xd29/0x1530 mm/vmalloc.c:4064 __vmalloc_node_noprof+0xad/0xf0 mm/vmalloc.c:4124 alloc_thread_stack_node kernel/fork.c:355 [inline] dup_task_struct kernel/fork.c:924 [inline] copy_process+0x5ec/0x7a40 kernel/fork.c:2050 kernel_clone+0xfc/0x9a0 kernel/fork.c:2653 kernel_thread+0xdb/0x120 kernel/fork.c:2714 create_kthread kernel/kthread.c:459 [inline] kthreadd+0x498/0x7a0 kernel/kthread.c:817 ret_from_fork+0x754/0xd80 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 page last free pid 5804 tgid 5804 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] __free_pages_prepare mm/page_alloc.c:1433 [inline] __free_frozen_pages+0x7e1/0x10d0 mm/page_alloc.c:2978 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x47/0xe0 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x1a0/0x1f0 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:350 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4538 [inline] slab_alloc_node mm/slub.c:4866 [inline] __kmalloc_cache_node_noprof+0x287/0x770 mm/slub.c:5388 kmalloc_node_noprof include/linux/slab.h:1077 [inline] __get_vm_area_node+0x101/0x330 mm/vmalloc.c:3221 __vmalloc_node_range_noprof+0x213/0x1530 mm/vmalloc.c:4024 __vmalloc_node_noprof+0xad/0xf0 mm/vmalloc.c:4124 __vmalloc_area_node mm/vmalloc.c:3852 [inline] __vmalloc_node_range_noprof+0xbc9/0x1530 mm/vmalloc.c:4064 vmalloc_user_noprof+0x9e/0xe0 mm/vmalloc.c:4218 kcov_ioctl+0x4c/0x720 kernel/kcov.c:726 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:597 [inline] __se_sys_ioctl fs/ioctl.c:583 [inline] __x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Memory state around the buggy address: ffffc90003af7900: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffffc90003af7980: 00 00 00 00 00 00 00 00 f1 f1 f1 f1 f1 f1 02 f2 >ffffc90003af7a00: 04 f2 06 f2 f2 f2 00 02 f2 f2 04 f2 00 00 02 f2 ^ ffffc90003af7a80: f2 f2 f2 f2 00 00 00 00 00 f2 f2 f2 f2 f2 04 f2 ffffc90003af7b00: 00 f2 f2 f2 00 04 f3 f3 00 00 00 00 00 00 00 00 ==================================================================