Linux Kernel up to 6.12.109/6.18.50/7.2.4/7.3-rc1 nvme-fc drivers/nvme/host/fc.c nvme_fc_init_ctrl opts double free

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9.5$5k-$25k0.00

Summaryinfo

A vulnerability, which was classified as very critical, has been found in Linux Kernel up to 6.12.109/6.18.50/7.2.4/7.3-rc1. This impacts the function nvme_fc_init_ctrl of the file drivers/nvme/host/fc.c of the component nvme-fc. Performing a manipulation of the argument opts results in double free. This vulnerability is reported as CVE-2026-89974. The attack is possible to be carried out remotely. No exploit exists. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability, which was classified as very critical, was found in Linux Kernel up to 6.12.109/6.18.50/7.2.4/7.3-rc1. This affects the function nvme_fc_init_ctrl of the file drivers/nvme/host/fc.c of the component nvme-fc. The manipulation of the argument opts with an unknown input leads to a double free vulnerability. CWE is classifying the issue as CWE-415. The product calls free() twice on the same memory address, potentially leading to modification of unexpected memory locations. This is going to have an impact on confidentiality, integrity, and availability. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: nvme-fc: fix double free of fabrics options when nvme_add_ctrl() fails nvmf_create_ctrl() owns the fabrics options and frees them whenever ->create_ctrl() returns an error, so a transport must not free them on its own error paths. nvme-fc tracks this by testing ctrl->ctrl.opts in nvme_fc_ctrl_free(), which requires nvme_fc_init_ctrl() to clear that pointer on every error exit. The coupling is implicit, and commit 1a9e218195a5 ("nvme: split device add from initialization") broke it by adding a second error exit. When nvme_add_ctrl() fails, nvme_fc_init_ctrl() jumps to out_put_ctrl:, past the "ctrl->ctrl.opts = NULL" that only sits on the fail_ctrl: path, so nvme_fc_ctrl_free() frees the options and nvmf_create_ctrl() frees them a second time: BUG: KASAN: slab-use-after-free in nvmf_free_options+0x30/0x190 nvmf_free_options+0x30/0x190 drivers/nvme/host/fabrics.c:1284 nvmf_create_ctrl drivers/nvme/host/fabrics.c:1374 [inline] Freed by task 5534: nvme_fc_ctrl_free drivers/nvme/host/fc.c:2374 [inline] nvme_fc_init_ctrl+0xe17/0x1450 drivers/nvme/host/fc.c:3605 nvme_add_ctrl() fails when dev_set_name() cannot allocate, so this is reachable under memory pressure or fault injection. Without KASAN the options are freed twice. Rather than clear the pointer on the second exit as well, derive ownership the way nvme-tcp, nvme-rdma and nvme-loop do, from list membership: their free_ctrl leaves the options alone unless the controller made it onto the transport list. The list cannot simply be populated on the success path as it is there. nvme-fc runs the initial connect synchronously via flush_delayed_work(), and the controller has to be reachable on rport->ctrl_list for the whole of it: nvme_fc_unregister_remoteport() needs to find it to signal connectivity loss, nvme_fc_match_disconn_ls() matches an incoming Disconnect Association LS against ctrl->association_id, which is only assigned during that window, nvme_fc_resume_controller() needs it on remoteport re-registration, and nvme_fc_existing_controller() uses it to reject a duplicate connect racing the one in flight. Keep the insertion where it is and add a fail_unlist: label, falling into fail_ctrl:, for the error paths that run after it. The earlier error paths never reach the insertion and keep using fail_ctrl: directly, so the list is only touched where the controller is actually on it. nvme_fc_ctrl_free() cannot use the plain "goto free_ctrl" the other transports use, because it still has to put_device(), release the rport reference and free the ida entry for resources taken before the insertion. Sample list_empty() under rport->lock instead. ctrl->ctrl.opts also stays valid for the whole teardown now. That is not the bug being fixed, but it removes some fragility around the old idiom: nvme_free_ctrl() calls nvme_auth_free() before ->free_ctrl(), and ctrl_max_dhchaps() dereferences ctrl->opts without a NULL check when ctrl->dhchap_ctxs is set, which nvme-fc permits since NVMF_ALLOWED_OPTS allows the dhchap options. The nvme sysfs attributes that dereference ctrl->opts, such as hostnqn and address, evaluate their is_visible() test once at device_add() time and stay readable until cdev_device_del().

The advisory is shared at git.kernel.org. This vulnerability is uniquely identified as CVE-2026-89974 since 09/11/2026. The exploitability is told to be easy. It is possible to initiate the attack remotely. Technical details are known, but no exploit is available. The price for an exploit might be around USD $5k-$25k at the moment (estimation calculated on 09/16/2026).

Upgrading to version 6.12.110, 6.18.51, 7.2.5 or 7.3-rc2 eliminates this vulnerability. Applying the patch 8bd14aa065112b4d523bea690027c7527a6224f6/7df913a7ced5d7349f0b23bdcf25ad54fe83a1c1/5f89d68c00ccd1b25151da0bf660012380c2bad9/56e6279266f6962bb2d38a54397e3c605165b0c5 is able to eliminate this problem. The best possible mitigation is suggested to be upgrading to the latest version.

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Productinfo

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Version

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CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 9.9
VulDB Meta Temp Score: 9.5

VulDB Base Score: 9.9
VulDB Temp Score: 9.5
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AVACAuCIA
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💳💳💳💳💳💳
💳💳💳💳💳💳
VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Double free
CWE: CWE-415 / CWE-119
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 6.12.110/6.18.51/7.2.5/7.3-rc2
Patch: 8bd14aa065112b4d523bea690027c7527a6224f6/7df913a7ced5d7349f0b23bdcf25ad54fe83a1c1/5f89d68c00ccd1b25151da0bf660012380c2bad9/56e6279266f6962bb2d38a54397e3c605165b0c5

Timelineinfo

09/11/2026 CVE reserved
09/16/2026 +5 days Advisory disclosed
09/16/2026 +0 days VulDB entry created
09/16/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-89974 (🔒)
GCVE (CVE): GCVE-0-2026-89974
GCVE (VulDB): GCVE-100-405777

Entryinfo

Created: 09/16/2026 14:51
Changes: 09/16/2026 14:51 (61)
Complete: 🔍
Cache ID: 216::103

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