{"id":"DEBIAN-CVE-2023-52568","details":"In the Linux kernel, the following vulnerability has been resolved:  x86/sgx: Resolves SECS reclaim vs. page fault for EAUG race  The SGX EPC reclaimer (ksgxd) may reclaim the SECS EPC page for an enclave and set secs.epc_page to NULL. The SECS page is used for EAUG and ELDU in the SGX page fault handler. However, the NULL check for secs.epc_page is only done for ELDU, not EAUG before being used.  Fix this by doing the same NULL check and reloading of the SECS page as needed for both EAUG and ELDU.  The SECS page holds global enclave metadata. It can only be reclaimed when there are no other enclave pages remaining. At that point, virtually nothing can be done with the enclave until the SECS page is paged back in.  An enclave can not run nor generate page faults without a resident SECS page. But it is still possible for a #PF for a non-SECS page to race with paging out the SECS page: when the last resident non-SECS page A triggers a #PF in a non-resident page B, and then page A and the SECS both are paged out before the #PF on B is handled.  Hitting this bug requires that race triggered with a #PF for EAUG. Following is a trace when it happens.  BUG: kernel NULL pointer dereference, address: 0000000000000000 RIP: 0010:sgx_encl_eaug_page+0xc7/0x210 Call Trace:  ? __kmem_cache_alloc_node+0x16a/0x440  ? xa_load+0x6e/0xa0  sgx_vma_fault+0x119/0x230  __do_fault+0x36/0x140  do_fault+0x12f/0x400  __handle_mm_fault+0x728/0x1110  handle_mm_fault+0x105/0x310  do_user_addr_fault+0x1ee/0x750  ? __this_cpu_preempt_check+0x13/0x20  exc_page_fault+0x76/0x180  asm_exc_page_fault+0x27/0x30","modified":"2026-09-15T09:02:47.920982456Z","published":"2024-03-02T22:15:49.120Z","upstream":["CVE-2023-52568"],"references":[{"type":"ADVISORY","url":"https://security-tracker.debian.org/tracker/CVE-2023-52568"}],"affected":[{"package":{"name":"linux","ecosystem":"Debian:12","purl":"pkg:deb/debian/linux?arch=source&distro=bookworm"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.1.64-1"}]}],"versions":["6.1.27-1","6.1.37-1","6.1.38-1","6.1.38-2","6.1.38-2~bpo11+1","6.1.38-3","6.1.38-4","6.1.38-4~bpo11+1","6.1.52-1","6.1.55-1","6.1.55-1~bpo11+1"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2023-52568.json"}},{"package":{"name":"linux","ecosystem":"Debian:13","purl":"pkg:deb/debian/linux?arch=source&distro=trixie"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.5.6-1"}]}],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2023-52568.json"}},{"package":{"name":"linux","ecosystem":"Debian:14","purl":"pkg:deb/debian/linux?arch=source&distro=forky"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.5.6-1"}]}],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2023-52568.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H"}]}