CVE-2026-53253Bluetooth: bnep: reject short frames before parsing

Official description

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: bnep: reject short frames before parsing A BNEP peer can send a short BNEP SDU. bnep_rx_frame() reads the packet type byte immediately and, for control packets, reads the control opcode and setup UUID-size byte before proving that those bytes are present. bnep_rx_control() also dereferences the control opcode without rejecting an empty control payload. Use skb_pull_data() for the fixed fields in bnep_rx_frame() so a NULL return gates each dereference. Split the control handler so the frame path can pass an opcode that has already been pulled, and keep the byte-buffer wrapper for extension control payloads. For BNEP_SETUP_CONN_REQ, name the UUID-size byte before pulling the setup payload. struct bnep_setup_conn_req carries destination and source service UUIDs after that byte, each uuid_size bytes, so the parser now documents that tuple explicitly instead of leaving the pull length as an opaque multiplication. Validation reproduced this kernel report: KASAN slab-out-of-bounds in bnep_rx_frame.isra.0+0x130c/0x1790 The buggy address belongs to the object at ffff88800c0f7908 which belongs to the cache kmalloc-8 of size 8 The buggy address is located 0 bytes to the right of allocated 1-byte region [ffff88800c0f7908, ffff88800c0f7909) Read of size 1 Call trace: dump_stack_lvl+0xb3/0x140 (?:?) print_address_description+0x57/0x3a0 (?:?) bnep_rx_frame+0x130c/0x1790 (net/bluetooth/bnep/core.c:306) print_report+0xb9/0x2b0 (?:?) __virt_addr_valid+0x1ba/0x3a0 (?:?) srso_alias_return_thunk+0x5/0xfbef5 (?:?) kasan_addr_to_slab+0x21/0x60 (?:?) kasan_report+0xe0/0x110 (?:?) process_one_work+0xfce/0x17e0 (kernel/workqueue.c:3200) worker_thread+0x65c/0xe40 (?:?) __kthread_parkme+0x184/0x230 (?:?) kthread+0x35e/0x470 (?:?) _raw_spin_unlock_irq+0x28/0x50 (?:?) ret_from_fork+0x586/0x870 (?:?) __switch_to+0x74f/0xdc0 (?:?) ret_from_fork_asm+0x1a/0x30 (?:?)

Affected packages & fixed versions

Affected products (as reported)

References

• https://git.kernel.org/stable/c/0ef2ea86c82b2615902d085cd5a586fe9f58994f
• https://git.kernel.org/stable/c/2b83afb19293e4de700edae306115f18966dc4f9
• https://git.kernel.org/stable/c/691f14b6a48b637655755134f1e551c7c6fedc2e
• https://git.kernel.org/stable/c/d76dec1a37122bc16d83d059c08c0512ea8de909
• https://git.kernel.org/stable/c/c893e17d2809ec9c4b3f1cdd5847cecbc27a311b
• https://git.kernel.org/stable/c/be837cd09897e9e6e1958174501d467bdcbcc2bc
• https://git.kernel.org/stable/c/6770d3a8acdf9151769180cc3710346c4cfbe6f0
• https://cert-portal.siemens.com/productcert/html/ssa-784472.html