vulnerability
Ubuntu: (CVE-2026-43344): linux-nvidia vulnerability
| Severity | CVSS | Published | Added | Modified |
|---|---|---|---|---|
| 5 | (AV:L/AC:L/Au:S/C:N/I:N/A:C) | May 8, 2026 | May 25, 2026 | May 25, 2026 |
Description
In the Linux kernel, the following vulnerability has been resolved:
perf/x86/intel/uncore: Fix die ID init and look up bugs
In snbep_pci2phy_map_init(), in the nr_node_ids > 8 path,
uncore_device_to_die() may return -1 when all CPUs associated
with the UBOX device are offline.
Remove the WARN_ON_ONCE(die_id == -1) check for two reasons:
- The current code breaks out of the loop. This is incorrect because
pci_get_device() does not guarantee iteration in domain or bus order,
so additional UBOX devices may be skipped during the scan.
- Returning -EINVAL is incorrect, since marking offline buses with
die_id == -1 is expected and should not be treated as an error.
Separately, when NUMA is disabled on a NUMA-capable platform,
pcibus_to_node() returns NUMA_NO_NODE, causing uncore_device_to_die()
to return -1 for all PCI devices. As a result,
spr_update_device_location(), used on Intel SPR and EMR, ignores the
corresponding PMON units and does not add them to the RB tree.
Fix this by using uncore_pcibus_to_dieid(), which retrieves topology
from the UBOX GIDNIDMAP register and works regardless of whether NUMA
is enabled in Linux. This requires snbep_pci2phy_map_init() to be
added in spr_uncore_pci_init().
Keep uncore_device_to_die() only for the nr_node_ids > 8 case, where
NUMA is expected to be enabled.
Solution
References
- CVE-2026-43344
- https://attackerkb.com/topics/CVE-2026-43344
- CWE-617
- EUVD-EUVD-2026-28628
- https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-28628
- https://git.kernel.org/linus/a16d1ec4dd0cdcf689f324adde6067083bce9099
- https://git.kernel.org/stable/c/6a5dc3ee97581da2907fc7acd62853f07184de67
- https://git.kernel.org/stable/c/a16d1ec4dd0cdcf689f324adde6067083bce9099
- https://www.cve.org/CVERecord?id=CVE-2026-43344
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