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
Metrics
Affected Vendors & Products
References
History
Wed, 11 Dec 2024 16:45:00 +0000
Type | Values Removed | Values Added |
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First Time appeared |
Linux
Linux linux Kernel |
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CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:6.6:rc1:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:6.6:rc2:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:6.6:rc3:*:*:*:*:*:* |
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Vendors & Products |
Linux
Linux linux Kernel |
|
Metrics |
cvssV3_1
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cvssV3_1
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Mon, 04 Nov 2024 13:15:00 +0000
Type | Values Removed | Values Added |
---|---|---|
Metrics |
ssvc
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MITRE
Status: PUBLISHED
Assigner: Linux
Published: 2024-03-02T21:59:39.451Z
Updated: 2024-12-19T08:21:48.492Z
Reserved: 2024-03-02T21:55:42.567Z
Link: CVE-2023-52568
Vulnrichment
Updated: 2024-08-02T23:03:20.885Z
NVD
Status : Analyzed
Published: 2024-03-02T22:15:49.120
Modified: 2024-12-11T16:23:49.080
Link: CVE-2023-52568
Redhat