medium · CVSS v3 4.7
CVE-2026-98650
In the Linux kernel, the following vulnerability has been resolved: KVM: s390: Fix potential races in dat skey functions…
Description
In the Linux kernel, the following vulnerability has been resolved: KVM: s390: Fix potential races in dat skey functions When dat_cond_set_storage_key() finds a large page, it will conditionally set the storage key in absolute memory using large_crste_to_phys() to get the absolute address. There is a race window between dat_entry_walk() and large_crste_to_phys(): the large page could have been split concurrently, and large_crste_to_phys() might be called with a crste that does not designate a large page, leading to crashes. Similar issues were also present in dat_set_storage_key(). dat_get_storage_key() and dat_reset_reference_bit() did instead check for a potential concurrent splitting of the large page, but then handled it incorrectly. Fix by performing a READ_ONCE on the crste pointer, checking and using the result, instead of dereferencing the pointer again. In case a race is detacted, try dat_entry_walk() again.
Scores
- Severity
- medium
- CVSS v2
- 4.3
- CVSS v3
- 4.7
- CVSS v4
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- EPSS
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