Vigie VulnDBEuropean-hosted Vulnerability DB
EN
Menu

scsi: target: iscsi: Bound iscsi_encode_text_output() appends to rsp_buf (Linux Linux)

CVE-2026-63887
CRITICAL 9.8

En bref

Source
NVD
EPSS
EPSS 0.78 % · centile 56 ()
État
PUBLISHED
Publiée
Mise à jour
Attribuée par
Linux
Statut NVD
Analyzed

Rechercher sur…

Description

In the Linux kernel, the following vulnerability has been resolved: scsi: target: iscsi: Bound iscsi_encode_text_output() appends to rsp_buf iscsi_encode_text_output() concatenates "key=value\0" records into login->rsp_buf, an 8192-byte kzalloc(MAX_KEY_VALUE_PAIRS) buffer allocated in iscsit_alloc_login_setup_buffer(). The three sprintf() call sites in this function (lines 1398, 1411, 1424 in v7.1-rc2) never check the remaining buffer capacity: *length += sprintf(output_buf, "%s=%s", er->key, er->value); *length += 1; output_buf = textbuf + *length; The 8192-byte ceiling at iscsi_target_check_login_request() bounds the *input* Login PDU payload, but a single PDU can carry up to 2048 minimal four-byte "a=b\0" pairs, each unknown key expanding to a 16-byte "a=NotUnderstood\0" output record via iscsi_add_notunderstood_response(). 2048 * 16 = 32 KiB of output into an 8 KiB buffer, producing a ~24 KiB heap overrun in the kmalloc-8k slab. The fix introduces a static iscsi_encode_text_record() helper that uses snprintf() with a per-call bounds check against the remaining buffer, and threads a u32 textbuf_size parameter through iscsi_encode_text_output(). Both call sites in iscsi_target_handle_csg_zero() (PHASE_SECURITY) and iscsi_target_handle_csg_one() (PHASE_OPERATIONAL) pass MAX_KEY_VALUE_PAIRS. On overflow the encoder logs the condition, calls iscsi_release_extra_responses() to drop queued records, and returns -1; both caller sites now emit ISCSI_STATUS_CLS_INITIATOR_ERR / ISCSI_LOGIN_STATUS_INIT_ERR via iscsit_tx_login_rsp() before returning, so the initiator sees an explicit failed-login response rather than a silent connection drop. (Prior to this patch only the PHASE_OPERATIONAL caller did that; the PHASE_SECURITY caller is converted to the same shape.)

Faiblesses (CWE)

  • CWE-122 — Débordement de tampon sur le tas
  • CWE-120 — Copie de tampon sans vérification de taille (débordement classique)

Références

Scores

VersionScoreVecteurÉvalué par
CVSS 3.1CRITICAL 9.8CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HLinux
CVSS 3.1CRITICAL 9.8CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HNVD · 416baaa9-dc9f-4396-8d5f-8c081fb06d67 (Secondary)

Références européennes

Avis du CERT-FR

Configurations affectées (CPE NVD)

Produits affectés

ProduitVersions
Linux · Linuxaffected e48354ce078c079996f89d715dfa44814b4eba01 < cb84e974fb172bc71386289f37b78ea679410b39 ; affected e48354ce078c079996f89d715dfa44814b4eba01 < b19382dfc6e7dee6d3859ba44b6ca29e97a51627 ; affected e48354ce078c079996f89d715dfa44814b4eba01 < efe633e600a0ac68357206fede21b1ac8178f3b8 ; affected e48354ce078c079996f89d715dfa44814b4eba01 < 4e9f0c4a645c995bc75c06c7b3644254ffb4c76b ; affected e48354ce078c079996f89d715dfa44814b4eba01 < 30bf335e8fe170322080ee001f05ca29c50680b3 ; affected e48354ce078c079996f89d715dfa44814b4eba01 < 594a40360012ce5f94c715d5e3b20fa3af7d525a
Linux · Linuxaffected 3.1 ; unaffected 0 < 3.1 ; unaffected 5.10.259 ≤ 5.10.* ; unaffected 5.15.210 ≤ 5.15.* ; unaffected 6.1.176 ≤ 6.1.* ; unaffected 6.6.143 ≤ 6.6.*

Sources

SourceLicence
CVE List (CVEProject cvelistV5)CVE Program Terms of Use
EPSS (FIRST.org)FIRST — attribution requested
ENISA EUVDENISA — reproduction authorised, source acknowledged
CERT-FR (ANSSI)Licence Ouverte / Etalab 2.0
NVD (NIST) via fkie-cad/nvd-json-data-feedsPublic domain — this product uses data from the NVD API but is not endorsed or certified by the NVD