{"answers":{"affected":"It affects 1 product.","exploited":"There is no known exploitation of CVE-2025-21970 in the wild and no public exploit code.","fix":"Apply the vendor's patch.","what":"CVE-2025-21970 is a high-severity vulnerability in Linux kernel, published on 1 Apr 2025. 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-2025-21970 and fix it if it is affected.\n\nWhat it is: CVE-2025-21970 is a high-severity vulnerability in Linux kernel, published on 1 Apr 2025. 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-2025-21970 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-2025-21970/ (Markdown: https://insights.sbomify.com/CVE-2025-21970/index.md)","id":"CVE-2025-21970","markdown":"https://insights.sbomify.com/CVE-2025-21970/index.md","name":"CVE-2025-21970","record":{"aliases":["BELL-CVE-2025-21970","DEBIAN-CVE-2025-21970","GHSA-m5q5-9mr9-g93x","ROOT-OS-UBUNTU-2404-CVE-2025-21970","UBUNTU-CVE-2025-21970"],"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 mlx5 bridge driver causes a system crash when removing a LAG device from a bridge.","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":7.8,"severity":"high","source":"cna","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/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\nnet/mlx5: Bridge, fix the crash caused by LAG state check\n\nWhen removing LAG device from bridge, NETDEV_CHANGEUPPER event is\ntriggered. Driver finds the lower devices (PFs) to flush all the\noffloaded entries. And mlx5_lag_is_shared_fdb is checked, it returns\nfalse if one of PF is unloaded. In such case,\nmlx5_esw_bridge_lag_rep_get() and its caller return NULL, instead of\nthe alive PF, and the flush is skipped.\n\nBesides, the bridge fdb entry's lastuse is updated in mlx5 bridge\nevent handler. But this SWITCHDEV_FDB_ADD_TO_BRIDGE event can be\nignored in this case because the upper interface for bond is deleted,\nand the entry will never be aged because lastuse is never updated.\n\nTo make things worse, as the entry is alive, mlx5 bridge workqueue\nkeeps sending that event, which is then handled by kernel bridge\nnotifier. It causes the following crash when accessing the passed bond\nnetdev which is already destroyed.\n\nTo fix this issue, remove such checks. LAG state is already checked in\ncommit 15f8f168952f (\"net/mlx5: Bridge, verify LAG state when adding\nbond to bridge\"), driver still need to skip offload if LAG becomes\ninvalid state after initialization.\n\n Oops: stack segment: 0000 [#1] SMP\n CPU: 3 UID: 0 PID: 23695 Comm: kworker/u40:3 Tainted: G           OE      6.11.0_mlnx #1\n Tainted: [O]=OOT_MODULE, [E]=UNSIGNED_MODULE\n Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014\n Workqueue: mlx5_bridge_wq mlx5_esw_bridge_update_work [mlx5_core]\n RIP: 0010:br_switchdev_event+0x2c/0x110 [bridge]\n Code: 44 00 00 48 8b 02 48 f7 00 00 02 00 00 74 69 41 54 55 53 48 83 ec 08 48 8b a8 08 01 00 00 48 85 ed 74 4a 48 83 fe 02 48 89 d3 \u003c4c\u003e 8b 65 00 74 23 76 49 48 83 fe 05 74 7e 48 83 fe 06 75 2f 0f b7\n RSP: 0018:ffffc900092cfda0 EFLAGS: 00010297\n RAX: ffff888123bfe000 RBX: ffffc900092cfe08 RCX: 00000000ffffffff\n RDX: ffffc900092cfe08 RSI: 0000000000000001 RDI: ffffffffa0c585f0\n RBP: 6669746f6e690a30 R08: 0000000000000000 R09: ffff888123ae92c8\n R10: 0000000000000000 R11: fefefefefefefeff R12: ffff888123ae9c60\n R13: 0000000000000001 R14: ffffc900092cfe08 R15: 0000000000000000\n FS:  0000000000000000(0000) GS:ffff88852c980000(0000) knlGS:0000000000000000\n CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033\n CR2: 00007f15914c8734 CR3: 0000000002830005 CR4: 0000000000770ef0\n DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000\n DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400\n PKRU: 55555554\n Call Trace:\n  \u003cTASK\u003e\n  ? __die_body+0x1a/0x60\n  ? die+0x38/0x60\n  ? do_trap+0x10b/0x120\n  ? do_error_trap+0x64/0xa0\n  ? exc_stack_segment+0x33/0x50\n  ? asm_exc_stack_segment+0x22/0x30\n  ? br_switchdev_event+0x2c/0x110 [bridge]\n  ? sched_balance_newidle.isra.149+0x248/0x390\n  notifier_call_chain+0x4b/0xa0\n  atomic_notifier_call_chain+0x16/0x20\n  mlx5_esw_bridge_update+0xec/0x170 [mlx5_core]\n  mlx5_esw_bridge_update_work+0x19/0x40 [mlx5_core]\n  process_scheduled_works+0x81/0x390\n  worker_thread+0x106/0x250\n  ? bh_worker+0x110/0x110\n  kthread+0xb7/0xe0\n  ? kthread_park+0x80/0x80\n  ret_from_fork+0x2d/0x50\n  ? kthread_park+0x80/0x80\n  ret_from_fork_asm+0x11/0x20\n  \u003c/TASK\u003e","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":"net/mlx5: Bridge, fix the crash caused by LAG state check","id":"CVE-2025-21970","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":"linux:linux_kernel","products":["linux:linux_kernel"],"type":"null_dereference","year":"2025"},"n_packages":0,"n_references":6,"next":{"headline":"net_sched: Prevent creation of classes with TC_H_ROOT","id":"CVE-2025-21971"},"packages":[],"prev":{"headline":"Bluetooth: L2CAP: Fix slab-use-after-free Read in l2cap_send_cmd","id":"CVE-2025-21969"},"products":["Linux"],"published":"2025-04-01","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":"total"},"state":"PUBLISHED","updated":"2026-10-15","vendors":["Linux"]},"summary":"A null pointer dereference in the Linux kernel mlx5 bridge driver causes a system crash when removing a LAG device from a bridge.","url":"https://insights.sbomify.com/CVE-2025-21970/"}