{"answers":{"affected":"It affects 1 product.","exploited":"There is no known exploitation of CVE-2024-47706 in the wild and no public exploit code.","fix":"Apply the vendor's patch.","what":"CVE-2024-47706 is a high-severity use after free vulnerability in Linux kernel, published on 21 Oct 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-2024-47706 and fix it if it is affected.\n\nWhat it is: CVE-2024-47706 is a high-severity use after free vulnerability in Linux kernel, published on 21 Oct 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-2024-47706 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-2024-47706/ (Markdown: https://insights.sbomify.com/CVE-2024-47706/index.md)","id":"CVE-2024-47706","markdown":"https://insights.sbomify.com/CVE-2024-47706/index.md","name":"CVE-2024-47706","record":{"aliases":["AZL-51108","AZL-51234","BELL-CVE-2024-47706","DEBIAN-CVE-2024-47706","GHSA-wchf-3rq4-vh73","UBUNTU-CVE-2024-47706"],"analysis":{"component_type":"kernel","fix_type":"patch","impacts":["code_execution","privilege_escalation"],"network_reachable":"adjacent_or_local","non_default_config":false,"product_category":"Linux kernel","requires_auth":"low_privilege","summary":"A use-after-free vulnerability in the Linux kernel BFQ I/O scheduler allows local attackers to potentially execute arbitrary code or escalate privileges.","user_interaction":"not_required","vuln_class":"use_after_free"},"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-416","name":"Use After Free"}],"description":"In the Linux kernel, the following vulnerability has been resolved:\n\nblock, bfq: fix possible UAF for bfqq-\u003ebic with merge chain\n\n1) initial state, three tasks:\n\n\t\tProcess 1       Process 2\tProcess 3\n\t\t (BIC1)          (BIC2)\t\t (BIC3)\n\t\t  |  Λ            |  Λ\t\t  |  Λ\n\t\t  |  |            |  |\t\t  |  |\n\t\t  V  |            V  |\t\t  V  |\n\t\t  bfqq1           bfqq2\t\t  bfqq3\nprocess ref:\t   1\t\t    1\t\t    1\n\n2) bfqq1 merged to bfqq2:\n\n\t\tProcess 1       Process 2\tProcess 3\n\t\t (BIC1)          (BIC2)\t\t (BIC3)\n\t\t  |               |\t\t  |  Λ\n\t\t  \\--------------\\|\t\t  |  |\n\t\t                  V\t\t  V  |\n\t\t  bfqq1---------\u003ebfqq2\t\t  bfqq3\nprocess ref:\t   0\t\t    2\t\t    1\n\n3) bfqq2 merged to bfqq3:\n\n\t\tProcess 1       Process 2\tProcess 3\n\t\t (BIC1)          (BIC2)\t\t (BIC3)\n\t here -\u003e Λ                |\t\t  |\n\t\t  \\--------------\\ \\-------------\\|\n\t\t                  V\t\t  V\n\t\t  bfqq1---------\u003ebfqq2----------\u003ebfqq3\nprocess ref:\t   0\t\t    1\t\t    3\n\nIn this case, IO from Process 1 will get bfqq2 from BIC1 first, and then\nget bfqq3 through merge chain, and finially handle IO by bfqq3.\nHowerver, current code will think bfqq2 is owned by BIC1, like initial\nstate, and set bfqq2-\u003ebic to BIC1.\n\nbfq_insert_request\n-\u003e by Process 1\n bfqq = bfq_init_rq(rq)\n  bfqq = bfq_get_bfqq_handle_split\n   bfqq = bic_to_bfqq\n   -\u003e get bfqq2 from BIC1\n bfqq-\u003eref++\n rq-\u003eelv.priv[0] = bic\n rq-\u003eelv.priv[1] = bfqq\n if (bfqq_process_refs(bfqq) == 1)\n  bfqq-\u003ebic = bic\n  -\u003e record BIC1 to bfqq2\n\n  __bfq_insert_request\n   new_bfqq = bfq_setup_cooperator\n   -\u003e get bfqq3 from bfqq2-\u003enew_bfqq\n   bfqq_request_freed(bfqq)\n   new_bfqq-\u003eref++\n   rq-\u003eelv.priv[1] = new_bfqq\n   -\u003e handle IO by bfqq3\n\nFix the problem by checking bfqq is from merge chain fist. And this\nmight fix a following problem reported by our syzkaller(unreproducible):\n\n==================================================================\nBUG: KASAN: slab-use-after-free in bfq_do_early_stable_merge block/bfq-iosched.c:5692 [inline]\nBUG: KASAN: slab-use-after-free in bfq_do_or_sched_stable_merge block/bfq-iosched.c:5805 [inline]\nBUG: KASAN: slab-use-after-free in bfq_get_queue+0x25b0/0x2610 block/bfq-iosched.c:5889\nWrite of size 1 at addr ffff888123839eb8 by task kworker/0:1H/18595\n\nCPU: 0 PID: 18595 Comm: kworker/0:1H Tainted: G             L     6.6.0-07439-gba2303cacfda #6\nHardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014\nWorkqueue: kblockd blk_mq_requeue_work\nCall Trace:\n \u003cTASK\u003e\n __dump_stack lib/dump_stack.c:88 [inline]\n dump_stack_lvl+0x91/0xf0 lib/dump_stack.c:106\n print_address_description mm/kasan/report.c:364 [inline]\n print_report+0x10d/0x610 mm/kasan/report.c:475\n kasan_report+0x8e/0xc0 mm/kasan/report.c:588\n bfq_do_early_stable_merge block/bfq-iosched.c:5692 [inline]\n bfq_do_or_sched_stable_merge block/bfq-iosched.c:5805 [inline]\n bfq_get_queue+0x25b0/0x2610 block/bfq-iosched.c:5889\n bfq_get_bfqq_handle_split+0x169/0x5d0 block/bfq-iosched.c:6757\n bfq_init_rq block/bfq-iosched.c:6876 [inline]\n bfq_insert_request block/bfq-iosched.c:6254 [inline]\n bfq_insert_requests+0x1112/0x5cf0 block/bfq-iosched.c:6304\n blk_mq_insert_request+0x290/0x8d0 block/blk-mq.c:2593\n blk_mq_requeue_work+0x6bc/0xa70 block/blk-mq.c:1502\n process_one_work kernel/workqueue.c:2627 [inline]\n process_scheduled_works+0x432/0x13f0 kernel/workqueue.c:2700\n worker_thread+0x6f2/0x1160 kernel/workqueue.c:2781\n kthread+0x33c/0x440 kernel/kthread.c:388\n ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147\n ret_from_fork_asm+0x1b/0x30 arch/x86/entry/entry_64.S:305\n \u003c/TASK\u003e\n\nAllocated by task 20776:\n kasan_save_stack+0x20/0x40 mm/kasan/common.c:45\n kasan_set_track+0x25/0x30 mm/kasan/common.c:52\n __kasan_slab_alloc+0x87/0x90 mm/kasan/common.c:328\n kasan_slab_alloc include/linux/kasan.h:188 [inline]\n slab_post_alloc_hook mm/slab.h:763 [inline]\n slab_alloc_node mm/slub.c:3458 [inline]\n kmem_cache_alloc_node+0x1a4/0x6f0 mm/slub.c:3503\n ioc_create_icq block/blk-ioc.c:370 [inline]\n---truncated---","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":"block, bfq: fix possible UAF for bfqq-\u003ebic with merge chain","id":"CVE-2024-47706","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":"linux:linux_kernel","products":["linux:linux_kernel"],"type":"use_after_free","year":"2024"},"n_packages":0,"n_references":9,"next":{"headline":"ipv6: avoid possible NULL deref in rt6_uncached_list_flush_dev()","id":"CVE-2024-47707"},"packages":[],"prev":{"headline":"block: fix potential invalid pointer dereference in blk_add_partition","id":"CVE-2024-47705"},"products":["Linux"],"published":"2024-10-21","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":"2026-10-15","vendors":["Linux"]},"summary":"A use-after-free vulnerability in the Linux kernel BFQ I/O scheduler allows local attackers to potentially execute arbitrary code or escalate privileges.","url":"https://insights.sbomify.com/CVE-2024-47706/"}