{"answers":{"affected":"It affects 1 product.","exploited":"There is no known exploitation of CVE-2021-46925 in the wild and no public exploit code.","fix":"Apply the vendor's patch.","what":"CVE-2021-46925 is a high-severity vulnerability in Linux kernel, published on 27 Feb 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-2021-46925 and fix it if it is affected.\n\nWhat it is: CVE-2021-46925 is a high-severity vulnerability in Linux kernel, published on 27 Feb 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-2021-46925 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-2021-46925/ (Markdown: https://insights.sbomify.com/CVE-2021-46925/index.md)","id":"CVE-2021-46925","markdown":"https://insights.sbomify.com/CVE-2021-46925/index.md","name":"CVE-2021-46925","record":{"aliases":["DEBIAN-CVE-2021-46925","GHSA-j3g9-72cw-7wcp","UBUNTU-CVE-2021-46925"],"analysis":{"component_type":"kernel","fix_type":"patch","impacts":["denial_of_service"],"network_reachable":"adjacent_or_local","non_default_config":false,"product_category":"Linux kernel","requires_auth":"low_privilege","summary":"A race condition in the Linux kernel's SMC protocol allows a local attacker to trigger a kernel panic via a use-after-free scenario.","user_interaction":"not_required","vuln_class":"race_condition"},"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-362","name":"Concurrent Execution using Shared Resource with Improper Synchronization"}],"description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet/smc: fix kernel panic caused by race of smc_sock\n\nA crash occurs when smc_cdc_tx_handler() tries to access smc_sock\nbut smc_release() has already freed it.\n\n[ 4570.695099] BUG: unable to handle page fault for address: 000000002eae9e88\n[ 4570.696048] #PF: supervisor write access in kernel mode\n[ 4570.696728] #PF: error_code(0x0002) - not-present page\n[ 4570.697401] PGD 0 P4D 0\n[ 4570.697716] Oops: 0002 [#1] PREEMPT SMP NOPTI\n[ 4570.698228] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.16.0-rc4+ #111\n[ 4570.699013] Hardware name: Alibaba Cloud Alibaba Cloud ECS, BIOS 8c24b4c 04/0\n[ 4570.699933] RIP: 0010:_raw_spin_lock+0x1a/0x30\n\u003c...\u003e\n[ 4570.711446] Call Trace:\n[ 4570.711746]  \u003cIRQ\u003e\n[ 4570.711992]  smc_cdc_tx_handler+0x41/0xc0\n[ 4570.712470]  smc_wr_tx_tasklet_fn+0x213/0x560\n[ 4570.712981]  ? smc_cdc_tx_dismisser+0x10/0x10\n[ 4570.713489]  tasklet_action_common.isra.17+0x66/0x140\n[ 4570.714083]  __do_softirq+0x123/0x2f4\n[ 4570.714521]  irq_exit_rcu+0xc4/0xf0\n[ 4570.714934]  common_interrupt+0xba/0xe0\n\nThough smc_cdc_tx_handler() checked the existence of smc connection,\nsmc_release() may have already dismissed and released the smc socket\nbefore smc_cdc_tx_handler() further visits it.\n\nsmc_cdc_tx_handler()           |smc_release()\nif (!conn)                     |\n                               |\n                               |smc_cdc_tx_dismiss_slots()\n                               |      smc_cdc_tx_dismisser()\n                               |\n                               |sock_put(\u0026smc-\u003esk) \u003c- last sock_put,\n                               |                      smc_sock freed\nbh_lock_sock(\u0026smc-\u003esk) (panic) |\n\nTo make sure we won't receive any CDC messages after we free the\nsmc_sock, add a refcount on the smc_connection for inflight CDC\nmessage(posted to the QP but haven't received related CQE), and\ndon't release the smc_connection until all the inflight CDC messages\nhaven been done, for both success or failed ones.\n\nUsing refcount on CDC messages brings another problem: when the link\nis going to be destroyed, smcr_link_clear() will reset the QP, which\nthen remove all the pending CQEs related to the QP in the CQ. To make\nsure all the CQEs will always come back so the refcount on the\nsmc_connection can always reach 0, smc_ib_modify_qp_reset() was replaced\nby smc_ib_modify_qp_error().\nAnd remove the timeout in smc_wr_tx_wait_no_pending_sends() since we\nneed to wait for all pending WQEs done, or we may encounter use-after-\nfree when handling CQEs.\n\nFor IB device removal routine, we need to wait for all the QPs on that\ndevice been destroyed before we can destroy CQs on the device, or\nthe refcount on smc_connection won't reach 0 and smc_sock cannot be\nreleased.","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/smc: fix kernel panic caused by race of smc_sock","id":"CVE-2021-46925","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":"linux:linux_kernel","products":["linux:linux_kernel"],"type":"race_condition","year":"2021"},"n_packages":0,"n_references":3,"next":{"headline":"ALSA: hda: intel-sdw-acpi: harden detection of controller","id":"CVE-2021-46926"},"packages":[],"prev":{"headline":"NFC: st21nfca: Fix memory leak in device probe and remove","id":"CVE-2021-46924"},"products":["Linux"],"published":"2024-02-27","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":"2026-08-05","vendors":["Linux"]},"summary":"A race condition in the Linux kernel's SMC protocol allows a local attacker to trigger a kernel panic via a use-after-free scenario.","url":"https://insights.sbomify.com/CVE-2021-46925/"}