CVE-2026-23384: RDMA/ionic: Fix kernel stack leak in ionic_create_cq()

Severity: medium (CVSS 5.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.1% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-03-25 · updated 2026-06-17
Weakness: CWE-401

Description

In the Linux kernel, the following vulnerability has been resolved: RDMA/ionic: Fix kernel stack leak in ionic_create_cq() struct ionic_cq_resp resp { __u32 cqid[2]; // offset 0 - PARTIALLY SET (see below) __u8 udma_mask; // offset 8 - SET (resp.udma_mask = vcq->udma_mask) __u8 rsvd[7]; // offset 9 - NEVER SET <- LEAK }; rsvd[7]: 7 bytes of stack memory leaked unconditionally. cqid[2]: The loop at line 1256 iterates over udma_idx but skips indices where !(vcq->udma_mask & BIT(udma_idx)). The array has 2 entries but udma_count could be 1, meaning cqid[1] might never be written via ionic_create_cq_common(). If udma_mask only has bit 0 set, cqid[1] (4 bytes) is also leaked. So potentially 11 bytes leaked.

Affected products

Linux kernel: from 6.18.1 before 6.18.17; from 6.19 before 6.19.7; 6.18, 7.0-rc1, 7.0-rc2, 7.0-rc3, 7.0-rc4, 7.0-rc5 (+2) — fixed in 6.18.17, 6.19.7

How to fix

Upgrade to a fixed version: Linux kernel 6.18.17, 6.19.7. Check the vendor advisory for mitigations.

References

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