================================================================== 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:3003 [inline] BUG: KASAN: stack-out-of-bounds in l2cap_send_cmd+0x2a3/0xb90 net/bluetooth/l2cap_core.c:954 Read of size 20 at addr ffffc90003ec7540 by task kworker/u9:4/5838 CPU: 0 UID: 0 PID: 5838 Comm: kworker/u9:4 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Workqueue: hci4 hci_rx_work Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0xba/0x230 mm/kasan/report.c:482 kasan_report+0x117/0x150 mm/kasan/report.c:595 check_region_inline mm/kasan/generic.c:-1 [inline] kasan_check_range+0x264/0x2c0 mm/kasan/generic.c:200 __asan_memcpy+0x29/0x70 mm/kasan/shadow.c:105 skb_put_data include/linux/skbuff.h:2800 [inline] l2cap_build_cmd net/bluetooth/l2cap_core.c:3003 [inline] l2cap_send_cmd+0x2a3/0xb90 net/bluetooth/l2cap_core.c:954 l2cap_ecred_conn_req net/bluetooth/l2cap_core.c:5208 [inline] l2cap_le_sig_cmd net/bluetooth/l2cap_core.c:5510 [inline] l2cap_le_sig_channel net/bluetooth/l2cap_core.c:5568 [inline] l2cap_recv_frame+0xc08a/0x102a0 net/bluetooth/l2cap_core.c:6918 l2cap_recv_acldata+0x7e9/0x13e0 net/bluetooth/l2cap_core.c:7642 hci_acldata_packet net/bluetooth/hci_core.c:3855 [inline] hci_rx_work+0x4f9/0x1040 net/bluetooth/hci_core.c:4082 process_one_work+0x949/0x1650 kernel/workqueue.c:3279 process_scheduled_works kernel/workqueue.c:3362 [inline] worker_thread+0xb46/0x1140 kernel/workqueue.c:3443 kthread+0x388/0x470 kernel/kthread.c:467 ret_from_fork+0x51e/0xb90 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/u9:4/5838 and is located at offset 128 in frame: l2cap_recv_frame+0x0/0x102a0 include/linux/skbuff.h:-1 This frame has 26 objects: [32, 34) 'rsp.i241.i.i' [48, 88) 'chan.i.i.i' [128, 146) 'pdu_u.i.i.i' [192, 202) 'rsp.i94.i.i' [224, 226) 'rsp.i.i.i111' [240, 242) 'rej.i' [256, 258) 'rej.i145.i' [272, 274) 'rej.i143.i' [288, 290) 'req.i229.i.i' [304, 312) 'buf.i222.i.i' [336, 348) 'buf29.i.i.i' [368, 372) 'rsp49.i.i.i' [384, 393) 'rfc.i.i118.i.i' [416, 480) 'buf.i119.i.i' [512, 576) 'req.i120.i.i' [608, 617) 'rfc.i.i.i.i' [640, 656) 'efs.i.i.i.i' [672, 678) 'rej.i371.i.i.i' [704, 710) 'rej.i.i.i.i' [736, 800) 'rsp.i.i.i' [832, 896) 'buf.i.i.i' [928, 1056) 'req.i.i.i' [1088, 1096) 'rsp.i.i.i.i' [1120, 1122) 'info.i.i.i.i' [1136, 1264) 'buf.i.i.i.i' [1296, 1298) 'rej.i.i' The buggy address belongs to a 8-page vmalloc region starting at 0xffffc90003ec0000 allocated at copy_process+0x508/0x3cf0 kernel/fork.c:2055 The buggy address belongs to the physical page: page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x77d4f 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 88028577114, free_ts 87899746694 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x231/0x280 mm/page_alloc.c:1889 prep_new_page mm/page_alloc.c:1897 [inline] get_page_from_freelist+0x24dc/0x2580 mm/page_alloc.c:3962 __alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5250 __alloc_pages_noprof+0xa/0x30 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:3655 [inline] __vmalloc_area_node mm/vmalloc.c:3875 [inline] __vmalloc_node_range_noprof+0x7c0/0x1a80 mm/vmalloc.c:4058 __vmalloc_node_noprof+0xc2/0x100 mm/vmalloc.c:4118 alloc_thread_stack_node kernel/fork.c:360 [inline] dup_task_struct+0x228/0x9e0 kernel/fork.c:927 copy_process+0x508/0x3cf0 kernel/fork.c:2055 kernel_clone+0x248/0x8e0 kernel/fork.c:2659 kernel_thread+0x13f/0x1b0 kernel/fork.c:2720 create_kthread kernel/kthread.c:490 [inline] kthreadd+0x4ec/0x6e0 kernel/kthread.c:848 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 page last free pid 5818 tgid 5818 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] __free_pages_prepare mm/page_alloc.c:1433 [inline] __free_frozen_pages+0xc2b/0xdb0 mm/page_alloc.c:2978 __slab_free+0x263/0x2b0 mm/slub.c:5551 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x97/0x100 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:350 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4515 [inline] slab_alloc_node mm/slub.c:4844 [inline] __kmalloc_cache_node_noprof+0x391/0x6b0 mm/slub.c:5366 kmalloc_node_noprof include/linux/slab.h:1077 [inline] __get_vm_area_node+0x13f/0x300 mm/vmalloc.c:3215 __vmalloc_node_range_noprof+0x355/0x1a80 mm/vmalloc.c:4018 vmalloc_user_noprof+0xad/0xe0 mm/vmalloc.c:4212 kcov_ioctl+0x55/0x620 kernel/kcov.c:726 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:597 [inline] __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Memory state around the buggy address: ffffc90003ec7400: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffffc90003ec7480: 00 00 00 00 00 00 00 00 f1 f1 f1 f1 f8 f2 f8 f8 >ffffc90003ec7500: f8 f8 f8 f2 f2 f2 f2 f2 00 00 02 f2 f2 f2 f2 f2 ^ ffffc90003ec7580: f8 f8 f2 f2 f8 f2 f8 f2 f8 f2 f8 f2 f8 f2 f8 f2 ffffc90003ec7600: f2 f2 f8 f8 f2 f2 f8 f2 f8 f8 f2 f2 f8 f8 f8 f8 ==================================================================