GHSA-XJX5-8V38-Q6GH
Vulnerability from github – Published: 2026-01-25 15:30 – Updated: 2026-03-18 18:31In the Linux kernel, the following vulnerability has been resolved:
nvme-tcp: fix NULL pointer dereferences in nvmet_tcp_build_pdu_iovec
Commit efa56305908b ("nvmet-tcp: Fix a kernel panic when host sends an invalid H2C PDU length") added ttag bounds checking and data_offset validation in nvmet_tcp_handle_h2c_data_pdu(), but it did not validate whether the command's data structures (cmd->req.sg and cmd->iov) have been properly initialized before processing H2C_DATA PDUs.
The nvmet_tcp_build_pdu_iovec() function dereferences these pointers without NULL checks. This can be triggered by sending H2C_DATA PDU immediately after the ICREQ/ICRESP handshake, before sending a CONNECT command or NVMe write command.
Attack vectors that trigger NULL pointer dereferences: 1. H2C_DATA PDU sent before CONNECT → both pointers NULL 2. H2C_DATA PDU for READ command → cmd->req.sg allocated, cmd->iov NULL 3. H2C_DATA PDU for uninitialized command slot → both pointers NULL
The fix validates both cmd->req.sg and cmd->iov before calling nvmet_tcp_build_pdu_iovec(). Both checks are required because: - Uninitialized commands: both NULL - READ commands: cmd->req.sg allocated, cmd->iov NULL - WRITE commands: both allocated
{
"affected": [],
"aliases": [
"CVE-2026-22998"
],
"database_specific": {
"cwe_ids": [
"CWE-476"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-01-25T15:15:54Z",
"severity": "MODERATE"
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nnvme-tcp: fix NULL pointer dereferences in nvmet_tcp_build_pdu_iovec\n\nCommit efa56305908b (\"nvmet-tcp: Fix a kernel panic when host sends an invalid H2C PDU length\")\nadded ttag bounds checking and data_offset\nvalidation in nvmet_tcp_handle_h2c_data_pdu(), but it did not validate\nwhether the command\u0027s data structures (cmd-\u003ereq.sg and cmd-\u003eiov) have\nbeen properly initialized before processing H2C_DATA PDUs.\n\nThe nvmet_tcp_build_pdu_iovec() function dereferences these pointers\nwithout NULL checks. This can be triggered by sending H2C_DATA PDU\nimmediately after the ICREQ/ICRESP handshake, before\nsending a CONNECT command or NVMe write command.\n\nAttack vectors that trigger NULL pointer dereferences:\n1. H2C_DATA PDU sent before CONNECT \u2192 both pointers NULL\n2. H2C_DATA PDU for READ command \u2192 cmd-\u003ereq.sg allocated, cmd-\u003eiov NULL\n3. H2C_DATA PDU for uninitialized command slot \u2192 both pointers NULL\n\nThe fix validates both cmd-\u003ereq.sg and cmd-\u003eiov before calling\nnvmet_tcp_build_pdu_iovec(). Both checks are required because:\n- Uninitialized commands: both NULL\n- READ commands: cmd-\u003ereq.sg allocated, cmd-\u003eiov NULL\n- WRITE commands: both allocated",
"id": "GHSA-xjx5-8v38-q6gh",
"modified": "2026-03-18T18:31:10Z",
"published": "2026-01-25T15:30:26Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-22998"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/32b63acd78f577b332d976aa06b56e70d054cbba"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/374b095e265fa27465f34780e0eb162ff1bef913"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/3def5243150716be86599c2a1767c29c68838b6d"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/76abc83a9d25593c2b7613c549413079c14a4686"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/7d75570002929d20e40110d6b03e46202c9d1bc7"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/baabe43a0edefac8cd7b981ff87f967f6034dafe"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/fdecd3b6aac10d5a18d0dc500fe57f8648b66cd4"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
}
]
}
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