Bug 2541091 (CVE-2026-97957)

Summary: CVE-2026-97957 kernel: net: hinic: fix mailbox segment buffer overflow
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: akhatavk, aos-team-art-private, asdas, dpaolell, jdelft, jupierce, lgarciaa, mbiarnes, ppalepu, ppostler, prdhamdh, rhel-process-autobot, sghai, sidsharm, suppawar, vlaad, watson-tool-maintainers
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
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Doc Text:
A flaw was found in the Linux kernel's hinic network driver. An attacker with access to send mailbox messages, such as from a guest operating system utilizing a Virtual Function (VF, a virtualized network interface), can exploit insufficient validation of message segment lengths. This flaw can cause a heap-based buffer overflow, potentially resulting in memory corruption or a Denial of Service (DoS) through a system crash.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
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Description OSIDB Bzimport 2026-09-25 10:47:50 UTC 
In the Linux kernel, the following vulnerability has been resolved:

net: hinic: fix mailbox segment buffer overflow

check_mbox_seq_id_and_seg_len() validates that seq_id does not
exceed SEQ_ID_MAX_VAL (42) and seg_len does not exceed
MBOX_SEG_LEN (48).  However, this allows the last segment
(seq_id=42) to carry a full 48-byte payload, writing to offset
42*48=2016 for 48 bytes (ending at byte 2064).  The receive
buffer is only MBOX_MAX_BUF_SZ (2048) bytes, resulting in a
16-byte heap buffer overflow.

The hinic3 driver already handles this correctly by defining
MBOX_LAST_SEG_MAX_LEN and rejecting the last segment when it
exceeds the remaining buffer space.  Apply the same fix to the
hinic driver.
Comment 1 gkamathe 2026-09-30 02:51:52 UTC 
Upstream advisory:
https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-97957.mbox