Description

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.

Classification

CVE ID: CVE-2024-50077

CVSS Base Severity: MEDIUM

CVSS Base Score: 5.5

CVSS Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Affected Products

Vendor: Linux

Product: Linux

Exploit Prediction Scoring System (EPSS)

EPSS Score: 0.03% (probability of being exploited)

EPSS Percentile: 6.53% (scored less or equal to compared to others)

EPSS Date: 2025-06-02 (when was this score calculated)

References

https://nvd.nist.gov/vuln/detail/CVE-2024-50077
https://git.kernel.org/stable/c/fa4b832c5a6ec35023a1b997cf658c436619c752
https://git.kernel.org/stable/c/8fb8e912afb4c47dec12ea9a5853e7a8db95816f
https://git.kernel.org/stable/c/adf1b179c2ff8073c24bf87e5a605fcc5a09798b
https://git.kernel.org/stable/c/a9b7b535ba192c6b77e6c15a4c82d853163eab8c

Timeline