Linux Kernel up to 7.3-rc1 nvme-tcp lib/iov_iter.c nvme_tcp_handle_c2h_data data_source information disclosure

CVSS Meta Temp Score
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4.1$0-$5k0.00

Summaryinfo

A vulnerability was found in Linux Kernel up to 7.3-rc1. It has been rated as problematic. This issue affects the function nvme_tcp_handle_c2h_data of the file lib/iov_iter.c of the component nvme-tcp. Performing a manipulation of the argument data_source results in information disclosure. This vulnerability was named CVE-2026-89973. The attack may be initiated remotely. There is no available exploit. Upgrading the affected component is advised.

Detailsinfo

A vulnerability classified as problematic has been found in Linux Kernel up to 7.3-rc1. This affects the function nvme_tcp_handle_c2h_data of the file lib/iov_iter.c of the component nvme-tcp. The manipulation of the argument data_source with an unknown input leads to a information disclosure vulnerability. CWE is classifying the issue as CWE-200. The product exposes sensitive information to an actor that is not explicitly authorized to have access to that information. This is going to have an impact on confidentiality. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: nvme-tcp: check the data direction of a C2HData PDU nvme_tcp_handle_c2h_data() finds the request by command id and checks that it has a payload, but it does not check that the command asked for data to be read. A controller that answers a write command with C2HData therefore reaches nvme_tcp_recv_data(), where _copy_to_iter() hits WARN_ON_ONCE(i->data_source) and returns 0. The receive path turns that into -EFAULT and resets the controller. No data is copied, so this is not memory corruption. What a controller gets is a kernel warning it can raise at will, which is fatal on a host booted with panic_on_warn. The send path already knows the direction - it consults rq_data_dir() when it builds a command - and nvme_tcp_handle_r2t() checks the length and the offset of the request it names. The C2HData path does not check the direction at all. Reject a C2HData PDU whose command is not a read. Rejecting it fails the command and resets the controller, as the neighbouring check in this function does; what goes away is the warning. [ 6.885580] ------------[ cut here ]------------ [ 6.886457] WARNING: lib/iov_iter.c:193 at _copy_to_iter+0x289/0x1330, CPU#0: kworker/0:1H/71 [ 6.888137] CPU: 0 UID: 0 PID: 71 Comm: kworker/0:1H Not tainted 7.2.0-rc5-NVMETCP-gf5098b6bae76 #1 PREEMPT(lazy) [ 6.891165] Workqueue: nvme_tcp_wq nvme_tcp_io_work [ 6.891875] RIP: 0010:_copy_to_iter+0x289/0x1330 [ 6.903739] Call Trace: [ 6.904085] <TASK> [ 6.909254] __skb_datagram_iter+0x433/0x820 [ 6.911026] skb_copy_datagram_iter+0x37/0x120 [ 6.911622] nvme_tcp_recv_skb+0xa07/0x4320 [ 6.913378] __tcp_read_sock+0x1ab/0x810 [ 6.915788] nvme_tcp_try_recv+0x152/0x1e0 [ 6.918222] nvme_tcp_io_work+0x1e4/0x6c0 [ 6.926906] </TASK> [ 6.927226] ---[ end trace 0000000000000000 ]--- [ 6.927878] nvme nvme0: queue 1 failed to copy request 0x71 data [ 6.928709] nvme nvme0: receive failed: -14

It is possible to read the advisory at git.kernel.org. This vulnerability is uniquely identified as CVE-2026-89973 since 09/11/2026. The exploitability is told to be easy. It is possible to initiate the attack remotely. Technical details of the vulnerability are known, but there is no available exploit. The pricing for an exploit might be around USD $0-$5k at the moment (estimation calculated on 09/16/2026). The attack technique deployed by this issue is T1592 according to MITRE ATT&CK.

Upgrading to version 5.10.270, 5.15.221, 6.1.188, 6.6.157, 6.12.110, 6.18.51, 7.2.5 or 7.3-rc2 eliminates this vulnerability. Applying the patch df74950ba6008655d4a977d17df7faf4b6e52b74/980d990f3c0560d7dfbfbf14699651fdf02f26ee/5b115d932f6e769ac80783fb18edd21b0aed256e/0673a2affe45ca76b60de31a83c67b1e60f81bde/80d56202fbdff8906be6954b2776e5c14a4026f2/b4af7999a998787d5eb6facb5a333e04a4f1d2d9/a0c389b8a495bda1eb719d2503853c924b7a8355/f83af377c148f6ad94b41c0e8313f12adf45e1c1 is able to eliminate this problem. The best possible mitigation is suggested to be upgrading to the latest version.

Be aware that VulDB is the high quality source for vulnerability data.

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: 4.3
VulDB Meta Temp Score: 4.1

VulDB Base Score: 4.3
VulDB Temp Score: 4.1
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: Information disclosure
CWE: CWE-200 / CWE-284 / CWE-266
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 5.10.270/5.15.221/6.1.188/6.6.157/6.12.110/6.18.51/7.2.5/7.3-rc2
Patch: df74950ba6008655d4a977d17df7faf4b6e52b74/980d990f3c0560d7dfbfbf14699651fdf02f26ee/5b115d932f6e769ac80783fb18edd21b0aed256e/0673a2affe45ca76b60de31a83c67b1e60f81bde/80d56202fbdff8906be6954b2776e5c14a4026f2/b4af7999a998787d5eb6facb5a333e04a4f1d2d9/a0c389b8a495bda1eb719d2503853c924b7a8355/f83af377c148f6ad94b41c0e8313f12adf45e1c1

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-2026-89973 (🔒)
GCVE (CVE): GCVE-0-2026-89973
GCVE (VulDB): GCVE-100-405783

Entryinfo

Created: 09/16/2026 14:55
Changes: 09/16/2026 14:55 (61)
Complete: 🔍
Cache ID: 216::103

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