Linux: NULL Pointer Dereference
CVE-2026-68305 is a high-severity NULL pointer dereference vulnerability in Linux, with a CVSS 3.1 base score of 7.8 out of 10. It can be exploited with local access to the system by an attacker with a low-privileged account, without any action from a user. The record lists versions 0c07e046e639160a1597830c4c5615ee2a4a5ed5, 523ed2831ee55b2a1edabdea96781651f9df9685, 4c92afb4c143526d340545ca581e88e6952ea511 as the first without the flaw, so updating Linux to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.17% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Linux to 0c07e046e639160a1597830c4c5615ee2a4a5ed5 or 523ed2831ee55b2a1edabdea96781651f9df9685 or 4c92afb4c143526d340545ca581e88e6952ea511, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | 864690cf4dd62482b6dd049d82c509886c904303 up to, but not including, 0c07e046e639160a1597830c4c5615ee2a4a5ed5; 864690cf4dd62482b6dd049d82c509886c904303 up to, but not including, 523ed2831ee55b2a1edabdea96781651f9df9685; 864690cf4dd62482b6dd049d82c509886c904303 up to, but not including, 4c92afb4c143526d340545ca581e88e6952ea511; 6.18 | 0c07e046e639160a1597830c4c5615ee2a4a5ed5, 523ed2831ee55b2a1edabdea96781651f9df9685, 4c92afb4c143526d340545ca581e88e6952ea511 |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- LocalThe attacker needs local access or must trick a user into running something.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- LowA basic user account is enough.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. Scored by CNA.
Official description
In the Linux kernel, the following vulnerability has been resolved: drm/xe/vf: Add drm_dev guards when detaching CCS read/write buffers CCS read/write buffers are freed during BO destruction. In some cases, BOs may be destroyed after the device is unbound but while the DRM structure remains valid, leading to NULL pointer dereferences when accessing device resources. BUG: kernel NULL pointer dereference, address: 0000000000000000 PGD 0 P4D 0 Oops: Oops: 0000 [#1] SMP NOPTI CPU: 0 UID: 0 PID: 9376 Comm: xe_pat Not tainted 7.2.0-rc2+ #1 PREEMPT(lazy) RIP: 0010:xe_sriov_vf_ccs_rw_update_bb_addr+0x4d/0xa0 [xe] RSP: 0018:ffffcf304110b9c8 EFLAGS: 00010246 RAX: ffff8a85c38a0a00 RBX: 00000000810ef000 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff8a85c39c1888 RBP: ffffcf304110b9e8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffff8a85c39c1888 R13: 0000000000000000 R14: ffff8a85c39b4f28 R15: ffff8a85c3885000 FS: 0000000000000000(0000) GS:ffff8a878b809000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 000000010314a002 CR4: 0000000000772ef0 PKRU: 55555554 Call Trace: <TASK> xe_migrate_ccs_rw_copy_clear+0x98/0x120 [xe] xe_sriov_vf_ccs_detach_bo+0x2c/0x60 [xe] xe_ttm_bo_delete_mem_notify+0xc8/0xe0 [xe] ttm_bo_cleanup_memtype_use+0x26/0x80 [ttm] ttm_bo_release+0x29e/0x2d0 [ttm] ttm_bo_fini+0x39/0x70 [ttm] xe_gem_object_free+0x1f/0x30 [xe] drm_gem_object_free+0x1d/0x40 ttm_bo_vm_close+0x5f/0x90 [ttm] remove_vma+0x2c/0x70 tear_down_vmas+0x63/0xf0 exit_mmap+0x20d/0x3f0 __mmput+0x45/0x170 mmput+0x31/0x40 do_exit+0x2ba/0xac0 do_group_exit+0x2d/0xb0 __x64_sys_exit_group+0x18/0x20 x64_sys_call+0x14a0/0x2390 do_syscall_64+0xdd/0x640 ? count_memcg_events+0xea/0x240 ? handle_mm_fault+0x1ec/0x2f0 (cherry picked from commit 1ae415a6eefe5004954a1d352b1718faca8844ef)
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: NULL Pointer Dereference
The product dereferences a pointer that it expects to be valid but is NULL.
How developers prevent this class of flaw
- For any pointers that could have been modified or provided from a function that can return NULL, check the pointer for NULL before use. When working with a multithreaded or otherwise asynchronous environment, ensure that proper locking APIs are used to lock before the check, and unlock when it has finished.
- Select a programming language that is not susceptible to these issues.
- Check the results of all functions that return a value and verify that the value is non-null before acting upon it.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Other references
Recent NULL Pointer Dereference vulnerabilities
- 7.5 High severity
- 9.8 Critical severity
- 8.8 High severity
- 7.5 High severity
- 7.5 High severity
- 9.8 Critical severity
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