# CVE-2023-52738: linux: In the Linux kernel, the following vulnerability has been resolved: drm/amdgpu/fence: Fix oops due to non-matching d... CVE-2023-52738 is fixed in linux on 1 platform, first by DEBIAN-CVE-2023-52738, released May 21, 2024. It is not reported as exploited. Patch Radar priority: Routine. - Web page: https://patchblox.com/security/cve/CVE-2023-52738 - Priority: Routine - CVSS: 5.3 (medium) - EPSS: 0.0080 - CISA KEV: not listed - Exploited (vendor report): no - Publicly disclosed: no - Published: May 21, 2024 ## Description In the Linux kernel, the following vulnerability has been resolved: drm/amdgpu/fence: Fix oops due to non-matching drm_sched init/fini Currently amdgpu calls drm_sched_fini() from the fence driver sw fini routine - such function is expected to be called only after the respective init function - drm_sched_init() - was executed successfully. Happens that we faced a driver probe failure in the Steam Deck recently, and the function drm_sched_fini() was called even without its counter-part had been previously called, causing the following oops: amdgpu: probe of 0000:04:00.0 failed with error -110 BUG: kernel NULL pointer dereference, address: 0000000000000090 PGD 0 P4D 0 Oops: 0002 [#1] PREEMPT SMP NOPTI CPU: 0 PID: 609 Comm: systemd-udevd Not tainted 6.2.0-rc3-gpiccoli #338 Hardware name: Valve Jupiter/Jupiter, BIOS F7A0113 11/04/2022 RIP: 0010:drm_sched_fini+0x84/0xa0 [gpu_sched] [...] Call Trace: amdgpu_fence_driver_sw_fini+0xc8/0xd0 [amdgpu] amdgpu_device_fini_sw+0x2b/0x3b0 [amdgpu] amdgpu_driver_release_kms+0x16/0x30 [amdgpu] devm_drm_dev_init_release+0x49/0x70 [...] To prevent that, check if the drm_sched was properly initialized for a given ring before calling its fini counter-part. Notice ideally we'd use sched.ready for that; such field is set as the latest thing on drm_sched_init(). But amdgpu seems to "override" the meaning of such field - in the above oops for example, it was a GFX ring causing the crash, and the sched.ready field was set to true in the ring init routine, regardless of the state of the DRM scheduler. Hence, we ended-up using sched.ops as per Christian's suggestion [0], and also removed the no_scheduler check [1]. [0] https://lore.kernel.org/amd-gfx/984ee981-2906-0eaf-ccec-9f80975cb136@amd.com/ [1] https://lore.kernel.org/amd-gfx/cd0e2994-f85f-d837-609f-7056d5fb7231@amd.com/ ## Where it's fixed | Platform | Product | Fixed in | Fix | Released | |---|---|---|---|---| | Linux | linux Debian 12.15 (bookworm) | 6.1.12-1 | [DEBIAN-CVE-2023-52738](https://patchblox.com/security/data/fix/linux/debian-cve-2023-52738.md) | May 21, 2024 | | Linux | linux Debian 13.5 (trixie) | 6.1.12-1 | [DEBIAN-CVE-2023-52738](https://patchblox.com/security/data/fix/linux/debian-cve-2023-52738.md) | May 21, 2024 | | Linux | linux Debian 14 | 6.1.12-1 | [DEBIAN-CVE-2023-52738](https://patchblox.com/security/data/fix/linux/debian-cve-2023-52738.md) | May 21, 2024 | --- Data as of 2026-11-09T19:38:12Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo Free to use with attribution: show "Data: Patchblox Patch Radar" with a link to https://patchblox.com/security/patch-radar. Terms, including what needs a written agreement: https://patchblox.com/security/patch-radar/use-the-data Product names, logos and trademarks shown on Patch Radar belong to their respective owners. They are used only to identify the software each security fix applies to and to help readers find their platform. Their use does not imply any affiliation with, or endorsement by, those owners, and Patchblox is not affiliated with any of them.