{"answers":{"affected":"It affects 1 product.","exploited":"There is no known exploitation of CVE-2023-52856 in the wild and no public exploit code.","fix":"Apply the vendor's patch.","what":"CVE-2023-52856 is a medium-severity vulnerability in Linux kernel, published on 21 May 2024. It can only be exploited from the same machine or local network, with no action from the victim."},"fix_prompt":"Check this codebase for CVE-2023-52856 and fix it if it is affected.\n\nWhat it is: CVE-2023-52856 is a medium-severity vulnerability in Linux kernel, published on 21 May 2024. It can only be exploited from the same machine or local network, with no action from the victim.\nExploitation: There is no known exploitation of CVE-2023-52856 in the wild and no public exploit code.\n\nAffected product: Linux kernel. No package-level version data is available, so check the vendor advisory linked from the reference page.\n\nTask:\n1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.\n2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.\n3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.\n4. Run the tests and summarise what changed and why.\n5. If nothing in the project is affected, say so and change nothing.\n\nReference: https://insights.sbomify.com/CVE-2023-52856/ (Markdown: https://insights.sbomify.com/CVE-2023-52856/index.md)","id":"CVE-2023-52856","markdown":"https://insights.sbomify.com/CVE-2023-52856/index.md","name":"CVE-2023-52856","record":{"aliases":["BELL-CVE-2023-52856","DEBIAN-CVE-2023-52856","GHSA-3qr9-g9f2-22xh","UBUNTU-CVE-2023-52856"],"analysis":{"component_type":"kernel","fix_type":"patch","impacts":["denial_of_service"],"network_reachable":"adjacent_or_local","non_default_config":false,"product_category":"Linux kernel driver","requires_auth":"low_privilege","summary":"A null pointer dereference in the Linux kernel's lt8912b bridge driver causes a system crash during bridge detach operations.","user_interaction":"not_required","vuln_class":"null_dereference"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"Linux","cpe":[{"product":"linux_kernel","vendor":"linux"}],"cvss":{"score":5.5,"severity":"medium","source":"nvd","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","version":"3.1"},"cwes":[{"id":"CWE-476","name":"NULL Pointer Dereference"}],"description":"In the Linux kernel, the following vulnerability has been resolved:\n\ndrm/bridge: lt8912b: Fix crash on bridge detach\n\nThe lt8912b driver, in its bridge detach function, calls\ndrm_connector_unregister() and drm_connector_cleanup().\n\ndrm_connector_unregister() should be called only for connectors\nexplicitly registered with drm_connector_register(), which is not the\ncase in lt8912b.\n\nThe driver's drm_connector_funcs.destroy hook is set to\ndrm_connector_cleanup().\n\nThus the driver should not call either drm_connector_unregister() nor\ndrm_connector_cleanup() in its lt8912_bridge_detach(), as they cause a\ncrash on bridge detach:\n\nUnable to handle kernel NULL pointer dereference at virtual address 0000000000000000\nMem abort info:\n  ESR = 0x0000000096000006\n  EC = 0x25: DABT (current EL), IL = 32 bits\n  SET = 0, FnV = 0\n  EA = 0, S1PTW = 0\n  FSC = 0x06: level 2 translation fault\nData abort info:\n  ISV = 0, ISS = 0x00000006, ISS2 = 0x00000000\n  CM = 0, WnR = 0, TnD = 0, TagAccess = 0\n  GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0\nuser pgtable: 4k pages, 48-bit VAs, pgdp=00000000858f3000\n[0000000000000000] pgd=0800000085918003, p4d=0800000085918003, pud=0800000085431003, pmd=0000000000000000\nInternal error: Oops: 0000000096000006 [#1] PREEMPT SMP\nModules linked in: tidss(-) display_connector lontium_lt8912b tc358768 panel_lvds panel_simple drm_dma_helper drm_kms_helper drm drm_panel_orientation_quirks\nCPU: 3 PID: 462 Comm: rmmod Tainted: G        W          6.5.0-rc2+ #2\nHardware name: Toradex Verdin AM62 on Verdin Development Board (DT)\npstate: 80000005 (Nzcv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--)\npc : drm_connector_cleanup+0x78/0x2d4 [drm]\nlr : lt8912_bridge_detach+0x54/0x6c [lontium_lt8912b]\nsp : ffff800082ed3a90\nx29: ffff800082ed3a90 x28: ffff0000040c1940 x27: 0000000000000000\nx26: 0000000000000000 x25: dead000000000122 x24: dead000000000122\nx23: dead000000000100 x22: ffff000003fb6388 x21: 0000000000000000\nx20: 0000000000000000 x19: ffff000003fb6260 x18: fffffffffffe56e8\nx17: 0000000000000000 x16: 0010000000000000 x15: 0000000000000038\nx14: 0000000000000000 x13: ffff800081914b48 x12: 000000000000040e\nx11: 000000000000015a x10: ffff80008196ebb8 x9 : ffff800081914b48\nx8 : 00000000ffffefff x7 : ffff0000040c1940 x6 : ffff80007aa649d0\nx5 : 0000000000000000 x4 : 0000000000000001 x3 : ffff80008159e008\nx2 : 0000000000000000 x1 : 0000000000000000 x0 : 0000000000000000\nCall trace:\n drm_connector_cleanup+0x78/0x2d4 [drm]\n lt8912_bridge_detach+0x54/0x6c [lontium_lt8912b]\n drm_bridge_detach+0x44/0x84 [drm]\n drm_encoder_cleanup+0x40/0xb8 [drm]\n drmm_encoder_alloc_release+0x1c/0x30 [drm]\n drm_managed_release+0xac/0x148 [drm]\n drm_dev_put.part.0+0x88/0xb8 [drm]\n devm_drm_dev_init_release+0x14/0x24 [drm]\n devm_action_release+0x14/0x20\n release_nodes+0x5c/0x90\n devres_release_all+0x8c/0xe0\n device_unbind_cleanup+0x18/0x68\n device_release_driver_internal+0x208/0x23c\n driver_detach+0x4c/0x94\n bus_remove_driver+0x70/0xf4\n driver_unregister+0x30/0x60\n platform_driver_unregister+0x14/0x20\n tidss_platform_driver_exit+0x18/0xb2c [tidss]\n __arm64_sys_delete_module+0x1a0/0x2b4\n invoke_syscall+0x48/0x110\n el0_svc_common.constprop.0+0x60/0x10c\n do_el0_svc_compat+0x1c/0x40\n el0_svc_compat+0x40/0xac\n el0t_32_sync_handler+0xb0/0x138\n el0t_32_sync+0x194/0x198\nCode: 9104a276 f2fbd5b7 aa0203e1 91008af8 (f85c0420)","ecosystems":[],"exploits":{"exploitdb":0,"first_seen":null,"github_poc":0,"max_poc_stars":null,"metasploit":0,"nuclei":0,"refs":[],"tier":"none_known"},"has_fix":true,"headline":"drm/bridge: lt8912b: Fix crash on bridge detach","id":"CVE-2023-52856","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":"linux:linux_kernel","products":["linux:linux_kernel"],"type":"null_dereference","year":"2023"},"n_packages":0,"n_references":5,"next":{"headline":"drm/mediatek: Fix coverity issue with unintentional integer overflow","id":"CVE-2023-52857"},"packages":[],"prev":{"headline":"usb: dwc2: fix possible NULL pointer dereference caused by driver concurrency","id":"CVE-2023-52855"},"products":["Linux"],"published":"2024-05-21","related":[{"cvss_score":8.8,"headline":"Linux Kernel Out-of-Bounds Write","id":"CVE-2026-53266","kev_date_added":"2026-09-18","published":"2026-06-25"},{"cvss_score":8.8,"headline":"Linux Kernel Improper Input Validation","id":"CVE-2013-6282","kev_date_added":"2022-09-15","published":"2013-11-19"},{"cvss_score":8.4,"headline":"Linux Kernel Heap-Based Buffer Overflow","id":"CVE-2022-0185","kev_date_added":"2024-08-21","published":"2022-02-11"},{"cvss_score":8.4,"headline":"Linux Kernel Privilege Escalation","id":"CVE-2013-2094","kev_date_added":"2022-09-15","published":"2013-05-14"},{"cvss_score":7.8,"headline":"Linux Kernel Unspecified","id":"CVE-2026-53362","kev_date_added":"2026-08-27","published":"2026-07-04"},{"cvss_score":7.8,"headline":"Linux Kernel Missing Initialization of a Variable","id":"CVE-2026-46300","kev_date_added":"2026-10-28","published":"2026-05-23"},{"cvss_score":7.8,"headline":"Linux Kernel Race Condition","id":"CVE-2025-39964","kev_date_added":"2026-09-18","published":"2025-10-13"}],"sources":[{"class":"attribution","licence":"CVE Terms of Use (MITRE)","name":"CVE List","prefix":"CVE"},{"class":"attribution","licence":"US public information, NVD API terms","name":"NVD"},{"class":"attribution","licence":"CWE Terms of Use","name":"CWE (MITRE)"},{"class":"attribution","licence":"FIRST CVSS licence","name":"CVSS (FIRST)"}],"ssvc":{"automatable":"no","exploitation":"none","technical_impact":"partial"},"state":"PUBLISHED","updated":"2026-05-11","vendors":["Linux"]},"summary":"A null pointer dereference in the Linux kernel's lt8912b bridge driver causes a system crash during bridge detach operations.","url":"https://insights.sbomify.com/CVE-2023-52856/"}