CVE-2024-57874 arm64: ptrace: fix partial SETREGSET for NT_ARM_TAGGED_ADDR_CTRL
A local attacker can leak up to 64 bits of kernel stack memory via a partial ptrace SETREGSET call on AArch64 systems.
- 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-2024-57874?
CVE-2024-57874 is a medium-severity vulnerability in Linux kernel, published on 11 Jan 2025. 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:
arm64: ptrace: fix partial SETREGSET for NT_ARM_TAGGED_ADDR_CTRL
Currently tagged_addr_ctrl_set() doesn't initialize the temporary 'ctrl' variable, and a SETREGSET call with a length of zero will leave this uninitialized. Consequently tagged_addr_ctrl_set() will consume an arbitrary value, potentially leaking up to 64 bits of memory from the kernel stack. The read is limited to a specific slot on the stack, and the issue does not provide a write mechanism.
As set_tagged_addr_ctrl() only accepts values where bits [63:4] zero and rejects other values, a partial SETREGSET attempt will randomly succeed or fail depending on the value of the uninitialized value, and the exposure is significantly limited.
Fix this by initializing the temporary value before copying the regset from userspace, as for other regsets (e.g. NT_PRSTATUS, NT_PRFPREG, NT_ARM_SYSTEM_CALL). In the case of a zero-length write, the existing value of the tagged address ctrl will be retained.
The NT_ARM_TAGGED_ADDR_CTRL regset is only visible in the user_aarch64_view used by a native AArch64 task to manipulate another native AArch64 task. As get_tagged_addr_ctrl() only returns an error value when called for a compat task, tagged_addr_ctrl_get() and tagged_addr_ctrl_set() should never observe an error value from get_tagged_addr_ctrl(). Add a WARN_ON_ONCE() to both to indicate that such an error would be unexpected, and error handlnig is not missing in either case.
Weakness: CWE-908
Which versions are affected by CVE-2024-57874?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2024-57874?
Apply the vendor's patch.
Is CVE-2024-57874 being exploited?
There is no known exploitation of CVE-2024-57874 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as AZL-56283, AZL-56354, BELL-CVE-2024-57874, DEBIAN-CVE-2024-57874, GHSA-xvfj-8qrf-7mc3, UBUNTU-CVE-2024-57874.