IB/isert: Reject login PDUs shorter than ISER_HEADERS_LEN

MITRE NVD CVE.ORG JSON API

Summary

CVECVE-2026-53176
StatePUBLISHED
AssignerLinux
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-06-25 09:16:34 UTC
Updated2026-07-15 01:16:30 UTC
DescriptionIn the Linux kernel, the following vulnerability has been resolved: IB/isert: Reject login PDUs shorter than ISER_HEADERS_LEN In drivers/infiniband/ulp/isert/ib_isert.c, isert_login_recv_done() computes the login request payload length as wc->byte_len minus ISER_HEADERS_LEN with no lower bound, and login_req_len is a signed int. A remote iSER initiator can post a login Send work request carrying fewer than ISER_HEADERS_LEN (76) bytes, so the subtraction underflows and login_req_len becomes negative. isert_rx_login_req() then reads that negative length back into a signed int, takes size = min(rx_buflen, MAX_KEY_VALUE_PAIRS), and because the min() is signed it keeps the negative value; the value is then passed as the memcpy() length and sign-extended to a multi-gigabyte size_t. The copy into the 8192-byte login->req_buf runs far out of bounds and faults, crashing the target node. The login phase precedes iSCSI authentication, so no credentials are required to reach this path. Reject any login PDU shorter than ISER_HEADERS_LEN before the subtraction, mirroring the existing early return on a failed work completion, so login_req_len can never go negative. The upper bound was already safe: a posted login buffer cannot deliver more than ISER_RX_PAYLOAD_SIZE, so the difference stays at or below MAX_KEY_VALUE_PAIRS and the existing min() clamps it; only the missing lower bound needs to be added.

Risk And Classification

Primary CVSS: v3.1 6.5 MEDIUM from ADP

CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS: 0.007370000 probability, percentile 0.500230000 (date 2026-07-04)

Problem Types: CWE-191 | CWE-839 | CWE-839 Numeric Range Comparison Without Minimum Check

VersionSourceTypeScoreSeverityVector
3.1ADPCVSS6.5MEDIUMCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
3.1416baaa9-dc9f-4396-8d5f-8c081fb06d67Secondary9.8CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
3.10b0ca135-0b70-47e7-9f44-1890c2a1c46cSecondary6.5MEDIUMCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
3.1CNADECLARED9.8CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CVSS v3.1 Breakdown

Attack Vector
Adjacent
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

NVD Known Affected Configurations (CPE 2.3)

TypeVendorProductVersionUpdateEditionLanguage
Operating System Linux Linux Kernel All All All All

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Linux Linux affected b8d26b3be8b33682cf163274ed07479a70554633 75ee6e4aa096aa9e7b2dd5c8ff98356e30aceefb git Not specified
CNA Linux Linux affected b8d26b3be8b33682cf163274ed07479a70554633 e8a013c0c3ca2f6708341a56612a3f6d6921620a git Not specified
CNA Linux Linux affected b8d26b3be8b33682cf163274ed07479a70554633 bd22740d7f14cb1c0289444cfd2c8d2938667c1d git Not specified
CNA Linux Linux affected b8d26b3be8b33682cf163274ed07479a70554633 c1234229399f4af12c553b1b0ffd978eeba65548 git Not specified
CNA Linux Linux affected b8d26b3be8b33682cf163274ed07479a70554633 c5584e089b5af7b3bf8bd5e8ca0560cbf32b0a47 git Not specified
CNA Linux Linux affected b8d26b3be8b33682cf163274ed07479a70554633 df422fd273c96c2ee5beb80fc21adc8c70c29260 git Not specified
CNA Linux Linux affected b8d26b3be8b33682cf163274ed07479a70554633 1ca40b243277c9e88be5e00bd3e083f71aefb93e git Not specified
CNA Linux Linux affected b8d26b3be8b33682cf163274ed07479a70554633 29e7b925ae6df64894e82ab6419994dc25580a8a git Not specified
CNA Linux Linux affected 3.10 Not specified
CNA Linux Linux unaffected 3.10 semver Not specified
CNA Linux Linux unaffected 5.10.259 5.10.* semver Not specified
CNA Linux Linux unaffected 5.15.210 5.15.* semver Not specified
CNA Linux Linux unaffected 6.1.176 6.1.* semver Not specified
CNA Linux Linux unaffected 6.6.143 6.6.* semver Not specified
CNA Linux Linux unaffected 6.12.94 6.12.* semver Not specified
CNA Linux Linux unaffected 6.18.36 6.18.* semver Not specified
CNA Linux Linux unaffected 7.0.13 7.0.* semver Not specified
CNA Linux Linux unaffected 7.1 * original_commit_for_fix Not specified
ADP Red Hat Red Hat Enterprise Linux 10 Not specified Not specified
ADP Red Hat Red Hat Enterprise Linux 6 Not specified Not specified
ADP Red Hat Red Hat Enterprise Linux 7 Not specified Not specified
ADP Red Hat Red Hat Enterprise Linux 7 Not specified Not specified
ADP Red Hat Red Hat Enterprise Linux 8 Not specified Not specified
ADP Red Hat Red Hat Enterprise Linux 8 Not specified Not specified
ADP Red Hat Red Hat Enterprise Linux 9 Not specified Not specified
ADP Red Hat Red Hat Enterprise Linux 9 Not specified Not specified

References

ReferenceSourceLinkTags
git.kernel.org/stable/c/e8a013c0c3ca2f6708341a56612a3f6d6921620a 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org Patch
git.kernel.org/stable/c/75ee6e4aa096aa9e7b2dd5c8ff98356e30aceefb 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org Patch
git.kernel.org/stable/c/c1234229399f4af12c553b1b0ffd978eeba65548 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org Patch
security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-53176.json 0b0ca135-0b70-47e7-9f44-1890c2a1c46c security.access.redhat.com Third Party Advisory
git.kernel.org/stable/c/1ca40b243277c9e88be5e00bd3e083f71aefb93e 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org Patch
bugzilla.redhat.com/show_bug.cgi 0b0ca135-0b70-47e7-9f44-1890c2a1c46c bugzilla.redhat.com Issue Tracking, Third Party Advisory
access.redhat.com/security/cve/CVE-2026-53176 0b0ca135-0b70-47e7-9f44-1890c2a1c46c access.redhat.com Third Party Advisory
git.kernel.org/stable/c/c5584e089b5af7b3bf8bd5e8ca0560cbf32b0a47 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org Patch
git.kernel.org/stable/c/bd22740d7f14cb1c0289444cfd2c8d2938667c1d 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org Patch
git.kernel.org/stable/c/29e7b925ae6df64894e82ab6419994dc25580a8a 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org Patch
git.kernel.org/stable/c/df422fd273c96c2ee5beb80fc21adc8c70c29260 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org Patch
CVE Program record CVE.ORG www.cve.org canonical
NVD vulnerability detail NVD nvd.nist.gov canonical, analysis

Additional Advisory Data

SourceTimeEvent
ADP2026-06-25T00:00:00.000ZReported to Red Hat.
ADP2026-06-25T00:00:00.000ZMade public.

Workarounds

ADP: To mitigate this issue, prevent module ib_isert from being loaded. Please see https://access.redhat.com/solutions/41278 for how to blacklist a kernel module to prevent it from loading automatically.

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