CVE-2024-50280 dm cache: fix flushing uninitialized delayed_work on cache_ctr error
A use-after-free vulnerability in the Linux kernel's dm cache module can cause a system crash when cache creation fails due to uninitialized work structures.
- 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-2024-50280?
CVE-2024-50280 is a high-severity use after free vulnerability in Linux kernel, published on 19 Nov 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:
dm cache: fix flushing uninitialized delayed_work on cache_ctr error
An unexpected WARN_ON from flush_work() may occur when cache creation fails, caused by destroying the uninitialized delayed_work waker in the error path of cache_create(). For example, the warning appears on the superblock checksum error.
Reproduce steps:
dmsetup create cmeta --table "0 8192 linear /dev/sdc 0" dmsetup create cdata --table "0 65536 linear /dev/sdc 8192" dmsetup create corig --table "0 524288 linear /dev/sdc 262144" dd if=/dev/urandom of=/dev/mapper/cmeta bs=4k count=1 oflag=direct dmsetup create cache --table "0 524288 cache /dev/mapper/cmeta \ /dev/mapper/cdata /dev/mapper/corig 128 2 metadata2 writethrough smq 0"
Kernel logs:
(snip) WARNING: CPU: 0 PID: 84 at kernel/workqueue.c:4178 __flush_work+0x5d4/0x890
Fix by pulling out the cancel_delayed_work_sync() from the constructor's error path. This patch doesn't affect the use-after-free fix for concurrent dm_resume and dm_destroy (commit 6a459d8edbdb ("dm cache: Fix UAF in destroy()")) as cache_dtr is not changed.
Weakness: CWE-416
Which versions are affected by CVE-2024-50280?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2024-50280?
Apply the vendor's patch.
Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.
Is CVE-2024-50280 being exploited?
There is no known exploitation of CVE-2024-50280 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as BELL-CVE-2024-50280, DEBIAN-CVE-2024-50280, GHSA-r79x-wgrg-2v77, ROOT-OS-UBUNTU-2204-CVE-2024-50280, UBUNTU-CVE-2024-50280.