CVE-2024-50077 Bluetooth: ISO: Fix multiple init when debugfs is disabled
A logic error in the Linux kernel Bluetooth ISO module causes a kernel panic when debugfs is disabled, leading to denial of service.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2024-50077?
CVE-2024-50077 is a high-severity denial of service vulnerability in Linux kernel, published on 29 Oct 2024. It can only be exploited from the same machine or local network, with no action from the victim.
Official 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.
Which versions are affected by CVE-2024-50077?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2024-50077?
Apply the vendor's patch.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2024-50077 being exploited?
There is no known exploitation of CVE-2024-50077 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as AZL-52061, BELL-CVE-2024-50077, DEBIAN-CVE-2024-50077, GHSA-hm8j-9qjw-g376, UBUNTU-CVE-2024-50077.