CVE-2024-50077

In the Linux kernel, the following vulnerability has been resolved:

Bluetooth: ISO: Fix multiple init when debugfs is disabled

If bt_debugfs is not created successfully, which happens if either

CONFIG_DEBUG_FS or CONFIG_DEBUG_FS_ALLOW_ALL is unset, then iso_init()

returns early and does not set iso_inited to true. This means that a

subsequent call to iso_init() will result in duplicate calls to

proto_register(), bt_sock_register(), etc.

With CONFIG_LIST_HARDENED and CONFIG_BUG_ON_DATA_CORRUPTION enabled, the

duplicate call to proto_register() triggers this BUG():

list_add double add: new=ffffffffc0b280d0, prev=ffffffffbab56250,

next=ffffffffc0b280d0.

------------[ cut here ]------------

kernel BUG at lib/list_debug.c:35!

Oops: invalid opcode: 0000 [#1] PREEMPT SMP PTI

CPU: 2 PID: 887 Comm: bluetoothd Not tainted 6.10.11-1-ao-desktop #1

RIP: 0010:__list_add_valid_or_report+0x9a/0xa0

...

__list_add_valid_or_report+0x9a/0xa0

proto_register+0x2b5/0x340

iso_init+0x23/0x150 [bluetooth]

set_iso_socket_func+0x68/0x1b0 [bluetooth]

kmem_cache_free+0x308/0x330

hci_sock_sendmsg+0x990/0x9e0 [bluetooth]

__sock_sendmsg+0x7b/0x80

sock_write_iter+0x9a/0x110

do_iter_readv_writev+0x11d/0x220

vfs_writev+0x180/0x3e0

do_writev+0xca/0x100

...

This change removes the early return. The check for iso_debugfs being

NULL was unnecessary, it is always NULL when iso_inited is false.