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Fencer Vulns
medium 5.5

CVE-2024-26657 json

drm/sched: fix null-ptr-deref in init entity

published 2024-04-02 2 y ago modified 2026-06-17 4 mo ago also EUVD-2024-23919

cvss
5.5
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 13%
public exploits
0
none known

Summary

In the Linux kernel, the following vulnerability has been resolved:

drm/sched: fix null-ptr-deref in init entity

The bug can be triggered by sending an amdgpu_cs_wait_ioctl to the AMDGPU DRM driver on any ASICs with valid context. The bug was reported by Joonkyo Jung <joonkyoj@yonsei.ac.kr>. For example the following code:

static void Syzkaller2(int fd) { union drm_amdgpu_ctx arg1; union drm_amdgpu_wait_cs arg2;

arg1.in.op = AMDGPU_CTX_OP_ALLOC_CTX; ret = drmIoctl(fd, 0x140106442 /* amdgpu_ctx_ioctl */, &arg1);

arg2.in.handle = 0x0; arg2.in.timeout = 0x2000000000000; arg2.in.ip_type = AMD_IP_VPE /* 0x9 */; arg2->in.ip_instance = 0x0; arg2.in.ring = 0x0; arg2.in.ctx_id = arg1.out.alloc.ctx_id;

drmIoctl(fd, 0xc0206449 /* AMDGPU_WAIT_CS * /, &arg2); }

The ioctl AMDGPU_WAIT_CS without previously submitted job could be assumed that the error should be returned, but the following commit 1decbf6bb0b4dc56c9da6c5e57b994ebfc2be3aa modified the logic and allowed to have sched_rq equal to NULL.

As a result when there is no job the ioctl AMDGPU_WAIT_CS returns success. The change fixes null-ptr-deref in init entity and the stack below demonstrates the error condition:

[ +0.000007] BUG: kernel NULL pointer dereference, address: 0000000000000028 [ +0.007086] #PF: supervisor read access in kernel mode [ +0.005234] #PF: error_code(0x0000) - not-present page [ +0.005232] PGD 0 P4D 0 [ +0.002501] Oops: 0000 [#1] PREEMPT SMP KASAN NOPTI [ +0.005034] CPU: 10 PID: 9229 Comm: amd_basic Tainted: G B W L 6.7.0+ #4 [ +0.007797] Hardware name: ASUS System Product Name/ROG STRIX B550-F GAMING (WI-FI), BIOS 1401 12/03/2020 [ +0.009798] RIP: 0010:drm_sched_entity_init+0x2d3/0x420 [gpu_sched] [ +0.006426] Code: 80 00 00 00 00 00 00 00 e8 1a 81 82 e0 49 89 9c 24 c0 00 00 00 4c 89 ef e8 4a 80 82 e0 49 8b 5d 00 48 8d 7b 28 e8 3d 80 82 e0 <48> 83 7b 28 00 0f 84 28 01 00 00 4d 8d ac 24 98 00 00 00 49 8d 5c [ +0.019094] RSP: 0018:ffffc90014c1fa40 EFLAGS: 00010282 [ +0.005237] RAX: 0000000000000001 RBX: 0000000000000000 RCX: ffffffff8113f3fa [ +0.007326] RDX: fffffbfff0a7889d RSI: 0000000000000008 RDI: ffffffff853c44e0 [ +0.007264] RBP: ffffc90014c1fa80 R08: 0000000000000001 R09: fffffbfff0a7889c [ +0.007266] R10: ffffffff853c44e7 R11: 0000000000000001 R12: ffff8881a719b010 [ +0.007263] R13: ffff88810d412748 R14: 0000000000000002 R15: 0000000000000000 [ +0.007264] FS: 00007ffff7045540(0000) GS:ffff8883cc900000(0000) knlGS:0000000000000000 [ +0.008236] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ +0.005851] CR2: 0000000000000028 CR3: 000000011912e000 CR4: 0000000000350ef0 [ +0.007175] Call Trace: [ +0.002561] <TASK> [ +0.002141] ? show_regs+0x6a/0x80 [ +0.003473] ? __die+0x25/0x70 [ +0.003124] ? page_fault_oops+0x214/0x720 [ +0.004179] ? preempt_count_sub+0x18/0xc0 [ +0.004093] ? __pfx_page_fault_oops+0x10/0x10 [ +0.004590] ? srso_return_thunk+0x5/0x5f [ +0.004000] ? vprintk_default+0x1d/0x30 [ +0.004063] ? srso_return_thunk+0x5/0x5f [ +0.004087] ? vprintk+0x5c/0x90 [ +0.003296] ? drm_sched_entity_init+0x2d3/0x420 [gpu_sched] [ +0.005807] ? srso_return_thunk+0x5/0x5f [ +0.004090] ? _printk+0xb3/0xe0 [ +0.003293] ? __pfx__printk+0x10/0x10 [ +0.003735] ? asm_sysvec_apic_timer_interrupt+0x1b/0x20 [ +0.005482] ? do_user_addr_fault+0x345/0x770 [ +0.004361] ? exc_page_fault+0x64/0xf0 [ +0.003972] ? asm_exc_page_fault+0x27/0x30 [ +0.004271] ? add_taint+0x2a/0xa0 [ +0.003476] ? drm_sched_entity_init+0x2d3/0x420 [gpu_sched] [ +0.005812] amdgpu_ctx_get_entity+0x3f9/0x770 [amdgpu] [ +0.009530] ? finish_task_switch.isra.0+0x129/0x470 [ +0.005068] ? __pfx_amdgpu_ctx_get_entity+0x10/0x10 [amdgpu] [ +0.010063] ? __kasan_check_write+0x14/0x20 [ +0.004356] ? srso_return_thunk+0x5/0x5f [ +0.004001] ? mutex_unlock+0x81/0xd0 [ +0.003802] ? srso_return_thunk+0x5/0x5f [ +0.004096] amdgpu_cs_wait_ioctl+0xf6/0x270 [amdgpu] [ +0.009355] ? __pfx_ ---truncated---

Patch / fix

  • Linux Linux 6.7.12, 6.8.3, 6.9
  • linux Debian 14, Debian 13 6.7.12-1

debian advisories DEBIAN-CVE-2024-26657

  • linux Ubuntu 24.04 LTS 6.8.0-35.35
  • linux-aws Ubuntu 24.04 LTS 6.8.0-1009.9
  • linux-gcp Ubuntu 24.04 LTS 6.8.0-1008.9
  • linux-gke Ubuntu 24.04 LTS 6.8.0-1004.7
  • linux-ibm Ubuntu 24.04 LTS 6.8.0-1006.6
  • linux-azure Ubuntu 24.04 LTS 6.8.0-1008.8
  • linux-raspi Ubuntu 24.04 LTS 6.8.0-1005.5
  • linux-riscv Ubuntu 24.04 LTS 6.8.0-35.35.1

ubuntu advisories UBUNTU-CVE-2024-26657

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • kernel-source Linux Micro 6.0 6.4.0-18.1
  • kernel-default Linux Micro 6.0 6.4.0-18.1
  • kernel-kvmsmall Linux Micro 6.0 6.4.0-18.1
  • kernel-default-base Linux Micro 6.0 6.4.0-17.1.1.51
  • kernel-rt Real Time Module 15 SP6, openSUSE Leap 15.6 6.4.0-150600.10.5.1
  • kernel-syms-rt Real Time Module 15 SP6, openSUSE Leap 15.6 6.4.0-150600.10.5.1
  • kernel-rt_debug Real Time Module 15 SP6, openSUSE Leap 15.6 6.4.0-150600.10.5.1
  • kernel-source-rt Real Time Module 15 SP6, openSUSE Leap 15.6 6.4.0-150600.10.5.1

suse advisories SUSE-SU-2025:20008-1SUSE-SU-2024:2973-1SUSE-SU-2024:2203-1SUSE-SU-2024:2135-1

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2024-26657 updated cvss 4.4

kernel: drm/sched: fix null-ptr-deref in init entity

  • Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more Red Hat Enterprise Linux 7 perf, kernel, bpftool, kernel-rt, python-perf, kernel-kdump, +8 more Red Hat Enterprise Linux 8 perf, kernel, bpftool, kernel-rt, kernel-core, kernel-tools, +29 more Red Hat Enterprise Linux 9 rv, perf, rtla, kernel, bpftool, libperf, +83 more
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
2 y ago

Exploit prediction

0.23% chance of exploitation in the next 30 days, higher than 13% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
NVD 3.1 5.5 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Affected products

  • Linux Linux

Classification

Weakness
Technology feeds

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.