nitro_enclaves: fix use-after-free on SLOT_ALLOC failure
- Published
- Last modified
- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean? →
- published
- Whether CISA lists it in its Known Exploited Vulnerabilities catalog: proof that attackers are using it.What do these mean? →
- Not listed in CISA KEV
- Fix
- Fixed in 6.6.160, 6.12.113, 6.18.56, 7.2.10
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
Summary
In the Linux kernel, the following vulnerability has been resolved: nitro_enclaves: fix use-after-free on SLOT_ALLOC failure When ne_create_vm_ioctl() fails the SLOT_ALLOC request after anon_inode_getfile() has succeeded, the error path calls fput(enclave_file) and then frees ne_enclave. In normal userspace context, fput() defers the final __fput() via task_work. ne_enclave_release() therefore runs after ne_enclave has already been freed and dereferences ne_enclave->slot_uid, causing a use-after-free: KASAN: slab-use-after-free in ne_enclave_release. The enclave has no slot allocated and is not yet linked into the enclaves list on this error path, so ne_enclave_release() is expected to return early when slot_uid is zero. However, reading slot_uid already accesses the freed object. Clear enclave_file->private_data before fput() on the error path. ne_enclave_release() then returns immediately when private_data is NULL, leaving the ioctl error path as the sole owner of ne_enclave. This is safe because the file has not been fd_install()'d yet. Tested on an AWS EC2 m5.2xlarge with CONFIG_KASAN=y. Without the patch, the reproducer triggers a KASAN slab-use-after-free on every SLOT_ALLOC failure. With the patch, no KASAN report is produced and the SLOT_ALLOC error is still returned. Normal enclave creation and teardown are unaffected.
Timeline
- CVE published
- Record last updated
Affected versions
- Linux Linux
From 9c8eb50fe9e2bb8a2e725979e052fbf592b6b799 · fixed in 8bde6f643ab6fe5e3e3f4c312f84ce327ecf39b2; From 9c8eb50fe9e2bb8a2e725979e052fbf592b6b799 · fixed in 466041d14f26dc2babd606a2e85dce08774112a6; From 9c8eb50fe9e2bb8a2e725979e052fbf592b6b799 · fixed in f7fb6c2835ede1b8ad84cf7e78a528a9d0159b84; From 9c8eb50fe9e2bb8a2e725979e052fbf592b6b799 · fixed in 43f78b328f3907ca2f7424e15b7e45ffbf9fe21c; From 9c8eb50fe9e2bb8a2e725979e052fbf592b6b799 · fixed in 9bc184a2eda8b773c88ecbff934001ad649b9cc1
- Linux Linux
5.10
- KernelLinux
From 5.10.0 · fixed in 6.6.160; From 6.7.0 · fixed in 6.12.113; From 6.13.0 · fixed in 6.18.56; From 6.19.0 · fixed in 7.2.10