{"answers":{"affected":"It affects 1 product.","exploited":"There is no known exploitation of CVE-2021-47038 in the wild and no public exploit code.","fix":"Apply the vendor's patch.","what":"CVE-2021-47038 is a medium-severity vulnerability in Linux kernel, published on 28 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-2021-47038 and fix it if it is affected.\n\nWhat it is: CVE-2021-47038 is a medium-severity vulnerability in Linux kernel, published on 28 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-2021-47038 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-2021-47038/ (Markdown: https://insights.sbomify.com/CVE-2021-47038/index.md)","id":"CVE-2021-47038","markdown":"https://insights.sbomify.com/CVE-2021-47038/index.md","name":"CVE-2021-47038","record":{"aliases":["DEBIAN-CVE-2021-47038","GHSA-3jvq-9rg9-g8rp","UBUNTU-CVE-2021-47038"],"analysis":{"component_type":"kernel","fix_type":"patch","impacts":["denial_of_service"],"network_reachable":"adjacent_or_local","non_default_config":false,"product_category":"Linux kernel Bluetooth","requires_auth":"low_privilege","summary":"A deadlock in the Linux kernel Bluetooth subsystem can cause a denial of service when specific socket operations are performed.","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":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-667","name":"Improper Locking"}],"description":"In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: avoid deadlock between hci_dev-\u003elock and socket lock\n\nCommit eab2404ba798 (\"Bluetooth: Add BT_PHY socket option\") added a\ndependency between socket lock and hci_dev-\u003elock that could lead to\ndeadlock.\n\nIt turns out that hci_conn_get_phy() is not in any way relying on hdev\nbeing immutable during the runtime of this function, neither does it even\nlook at any of the members of hdev, and as such there is no need to hold\nthat lock.\n\nThis fixes the lockdep splat below:\n\n ======================================================\n WARNING: possible circular locking dependency detected\n 5.12.0-rc1-00026-g73d464503354 #10 Not tainted\n ------------------------------------------------------\n bluetoothd/1118 is trying to acquire lock:\n ffff8f078383c078 (\u0026hdev-\u003elock){+.+.}-{3:3}, at: hci_conn_get_phy+0x1c/0x150 [bluetooth]\n\n but task is already holding lock:\n ffff8f07e831d920 (sk_lock-AF_BLUETOOTH-BTPROTO_L2CAP){+.+.}-{0:0}, at: l2cap_sock_getsockopt+0x8b/0x610\n\n which lock already depends on the new lock.\n\n the existing dependency chain (in reverse order) is:\n\n -\u003e #3 (sk_lock-AF_BLUETOOTH-BTPROTO_L2CAP){+.+.}-{0:0}:\n        lock_sock_nested+0x72/0xa0\n        l2cap_sock_ready_cb+0x18/0x70 [bluetooth]\n        l2cap_config_rsp+0x27a/0x520 [bluetooth]\n        l2cap_sig_channel+0x658/0x1330 [bluetooth]\n        l2cap_recv_frame+0x1ba/0x310 [bluetooth]\n        hci_rx_work+0x1cc/0x640 [bluetooth]\n        process_one_work+0x244/0x5f0\n        worker_thread+0x3c/0x380\n        kthread+0x13e/0x160\n        ret_from_fork+0x22/0x30\n\n -\u003e #2 (\u0026chan-\u003elock#2/1){+.+.}-{3:3}:\n        __mutex_lock+0xa3/0xa10\n        l2cap_chan_connect+0x33a/0x940 [bluetooth]\n        l2cap_sock_connect+0x141/0x2a0 [bluetooth]\n        __sys_connect+0x9b/0xc0\n        __x64_sys_connect+0x16/0x20\n        do_syscall_64+0x33/0x80\n        entry_SYSCALL_64_after_hwframe+0x44/0xae\n\n -\u003e #1 (\u0026conn-\u003echan_lock){+.+.}-{3:3}:\n        __mutex_lock+0xa3/0xa10\n        l2cap_chan_connect+0x322/0x940 [bluetooth]\n        l2cap_sock_connect+0x141/0x2a0 [bluetooth]\n        __sys_connect+0x9b/0xc0\n        __x64_sys_connect+0x16/0x20\n        do_syscall_64+0x33/0x80\n        entry_SYSCALL_64_after_hwframe+0x44/0xae\n\n -\u003e #0 (\u0026hdev-\u003elock){+.+.}-{3:3}:\n        __lock_acquire+0x147a/0x1a50\n        lock_acquire+0x277/0x3d0\n        __mutex_lock+0xa3/0xa10\n        hci_conn_get_phy+0x1c/0x150 [bluetooth]\n        l2cap_sock_getsockopt+0x5a9/0x610 [bluetooth]\n        __sys_getsockopt+0xcc/0x200\n        __x64_sys_getsockopt+0x20/0x30\n        do_syscall_64+0x33/0x80\n        entry_SYSCALL_64_after_hwframe+0x44/0xae\n\n other info that might help us debug this:\n\n Chain exists of:\n   \u0026hdev-\u003elock --\u003e \u0026chan-\u003elock#2/1 --\u003e sk_lock-AF_BLUETOOTH-BTPROTO_L2CAP\n\n  Possible unsafe locking scenario:\n\n        CPU0                    CPU1\n        ----                    ----\n   lock(sk_lock-AF_BLUETOOTH-BTPROTO_L2CAP);\n                                lock(\u0026chan-\u003elock#2/1);\n                                lock(sk_lock-AF_BLUETOOTH-BTPROTO_L2CAP);\n   lock(\u0026hdev-\u003elock);\n\n  *** DEADLOCK ***\n\n 1 lock held by bluetoothd/1118:\n  #0: ffff8f07e831d920 (sk_lock-AF_BLUETOOTH-BTPROTO_L2CAP){+.+.}-{0:0}, at: l2cap_sock_getsockopt+0x8b/0x610 [bluetooth]\n\n stack backtrace:\n CPU: 3 PID: 1118 Comm: bluetoothd Not tainted 5.12.0-rc1-00026-g73d464503354 #10\n Hardware name: LENOVO 20K5S22R00/20K5S22R00, BIOS R0IET38W (1.16 ) 05/31/2017\n Call Trace:\n  dump_stack+0x7f/0xa1\n  check_noncircular+0x105/0x120\n  ? __lock_acquire+0x147a/0x1a50\n  __lock_acquire+0x147a/0x1a50\n  lock_acquire+0x277/0x3d0\n  ? hci_conn_get_phy+0x1c/0x150 [bluetooth]\n  ? __lock_acquire+0x2e1/0x1a50\n  ? lock_is_held_type+0xb4/0x120\n  ? hci_conn_get_phy+0x1c/0x150 [bluetooth]\n  __mutex_lock+0xa3/0xa10\n  ? hci_conn_get_phy+0x1c/0x150 [bluetooth]\n  ? lock_acquire+0x277/0x3d0\n  ? mark_held_locks+0x49/0x70\n  ? mark_held_locks+0x49/0x70\n  ? hci_conn_get_phy+0x1c/0x150 [bluetooth]\n  hci_conn_get_phy+0x\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":"Bluetooth: avoid deadlock between hci_dev-\u003elock and socket lock","id":"CVE-2021-47038","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":4,"next":{"headline":"ataflop: potential out of bounds in do_format()","id":"CVE-2021-47039"},"packages":[],"prev":{"headline":"ASoC: q6afe-clocks: fix reprobing of the driver","id":"CVE-2021-47037"},"products":["Linux"],"published":"2024-02-28","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 deadlock in the Linux kernel Bluetooth subsystem can cause a denial of service when specific socket operations are performed.","url":"https://insights.sbomify.com/CVE-2021-47038/"}