CVE-2024-57877

In the Linux kernel, the following vulnerability has been resolved: arm64: ptrace: fix partial SETREGSET for NT_ARM_POE Currently poe_set() doesn't initialize the temporary 'ctrl' variable, and a SETREGSET call with a length of zero will leave this uninitialized. Consequently an arbitrary value will be written back to target->thread.por_el0, 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. 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 contents of POR_EL1 will be retained. Before this patch: | # ./poe-test | Attempting to write NT_ARM_POE::por_el0 = 0x900d900d900d900d | SETREGSET(nt=0x40f, len=8) wrote 8 bytes | | Attempting to read NT_ARM_POE::por_el0 | GETREGSET(nt=0x40f, len=8) read 8 bytes | Read NT_ARM_POE::por_el0 = 0x900d900d900d900d | | Attempting to write NT_ARM_POE (zero length) | SETREGSET(nt=0x40f, len=0) wrote 0 bytes | | Attempting to read NT_ARM_POE::por_el0 | GETREGSET(nt=0x40f, len=8) read 8 bytes | Read NT_ARM_POE::por_el0 = 0xffff8000839c3d50 After this patch: | # ./poe-test | Attempting to write NT_ARM_POE::por_el0 = 0x900d900d900d900d | SETREGSET(nt=0x40f, len=8) wrote 8 bytes | | Attempting to read NT_ARM_POE::por_el0 | GETREGSET(nt=0x40f, len=8) read 8 bytes | Read NT_ARM_POE::por_el0 = 0x900d900d900d900d | | Attempting to write NT_ARM_POE (zero length) | SETREGSET(nt=0x40f, len=0) wrote 0 bytes | | Attempting to read NT_ARM_POE::por_el0 | GETREGSET(nt=0x40f, len=8) read 8 bytes | Read NT_ARM_POE::por_el0 = 0x900d900d900d900d

The following products are affected by CVE-2024-57877 vulnerability.

Here, you will find a curated list of external links that provide in-depth information to CVE-2024-57877.

URL	Resource
https://git.kernel.org/stable/c/4105dd76bc8ad6529d47157ef0565cb84ca6676c
https://git.kernel.org/stable/c/594bfc4947c4fcabba1318d8384c61a29a6b89fb
https://lore.kernel.org/linux-cve-announce/2025011108-CVE-2024-57877-ee49@gregkh/T
https://nvd.nist.gov/vuln/detail/CVE-2024-57877
https://www.cve.org/CVERecord?id=CVE-2024-57877