{"answers":{"affected":"It affects 1 product.","exploited":"There is no known exploitation of CVE-2023-53685 in the wild and no public exploit code.","fix":"Apply the vendor's patch.","what":"CVE-2023-53685 is a medium-severity denial of service vulnerability in Linux kernel, published on 7 Oct 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-2023-53685 and fix it if it is affected.\n\nWhat it is: CVE-2023-53685 is a medium-severity denial of service vulnerability in Linux kernel, published on 7 Oct 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-2023-53685 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-2023-53685/ (Markdown: https://insights.sbomify.com/CVE-2023-53685/index.md)","id":"CVE-2023-53685","markdown":"https://insights.sbomify.com/CVE-2023-53685/index.md","name":"CVE-2023-53685","record":{"aliases":["AZL-76428","BELL-CVE-2023-53685","DEBIAN-CVE-2023-53685","GHSA-q99f-whjq-3rrx","ROOT-OS-DEBIAN-11-CVE-2023-53685","ROOT-OS-UBUNTU-2204-CVE-2023-53685","UBUNTU-CVE-2023-53685"],"analysis":{"component_type":"kernel","fix_type":"patch","impacts":["denial_of_service"],"network_reachable":"adjacent_or_local","non_default_config":true,"product_category":"Linux kernel","requires_auth":"low_privilege","summary":"A local attacker can cause a memory leak in the Linux kernel TUN driver by exploiting a race condition during queue detachment, leading to resource exhaustion.","user_interaction":"not_required","vuln_class":"denial_of_service"},"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-401","name":"Missing Release of Memory after Effective Lifetime"}],"description":"In the Linux kernel, the following vulnerability has been resolved:\n\ntun: Fix memory leak for detached NAPI queue.\n\nsyzkaller reported [0] memory leaks of sk and skb related to the TUN\ndevice with no repro, but we can reproduce it easily with:\n\n  struct ifreq ifr = {}\n  int fd_tun, fd_tmp;\n  char buf[4] = {};\n\n  fd_tun = openat(AT_FDCWD, \"/dev/net/tun\", O_WRONLY, 0);\n  ifr.ifr_flags = IFF_TUN | IFF_NAPI | IFF_MULTI_QUEUE;\n  ioctl(fd_tun, TUNSETIFF, \u0026ifr);\n\n  ifr.ifr_flags = IFF_DETACH_QUEUE;\n  ioctl(fd_tun, TUNSETQUEUE, \u0026ifr);\n\n  fd_tmp = socket(AF_PACKET, SOCK_PACKET, 0);\n  ifr.ifr_flags = IFF_UP;\n  ioctl(fd_tmp, SIOCSIFFLAGS, \u0026ifr);\n\n  write(fd_tun, buf, sizeof(buf));\n  close(fd_tun);\n\nIf we enable NAPI and multi-queue on a TUN device, we can put skb into\ntfile-\u003esk.sk_write_queue after the queue is detached.  We should prevent\nit by checking tfile-\u003edetached before queuing skb.\n\nNote this must be done under tfile-\u003esk.sk_write_queue.lock because write()\nand ioctl(IFF_DETACH_QUEUE) can run concurrently.  Otherwise, there would\nbe a small race window:\n\n  write()                             ioctl(IFF_DETACH_QUEUE)\n  `- tun_get_user                     `- __tun_detach\n     |- if (tfile-\u003edetached)             |- tun_disable_queue\n     |  `-\u003e false                        |  `- tfile-\u003edetached = tun\n     |                                   `- tun_queue_purge\n     |- spin_lock_bh(\u0026queue-\u003elock)\n     `- __skb_queue_tail(queue, skb)\n\nAnother solution is to call tun_queue_purge() when closing and\nreattaching the detached queue, but it could paper over another\nproblems.  Also, we do the same kind of test for IFF_NAPI_FRAGS.\n\n[0]:\nunreferenced object 0xffff88801edbc800 (size 2048):\n  comm \"syz-executor.1\", pid 33269, jiffies 4295743834 (age 18.756s)\n  hex dump (first 32 bytes):\n    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................\n    00 00 07 40 00 00 00 00 00 00 00 00 00 00 00 00  ...@............\n  backtrace:\n    [\u003c000000008c16ea3d\u003e] __do_kmalloc_node mm/slab_common.c:965 [inline]\n    [\u003c000000008c16ea3d\u003e] __kmalloc+0x4a/0x130 mm/slab_common.c:979\n    [\u003c000000003addde56\u003e] kmalloc include/linux/slab.h:563 [inline]\n    [\u003c000000003addde56\u003e] sk_prot_alloc+0xef/0x1b0 net/core/sock.c:2035\n    [\u003c000000003e20621f\u003e] sk_alloc+0x36/0x2f0 net/core/sock.c:2088\n    [\u003c0000000028e43843\u003e] tun_chr_open+0x3d/0x190 drivers/net/tun.c:3438\n    [\u003c000000001b0f1f28\u003e] misc_open+0x1a6/0x1f0 drivers/char/misc.c:165\n    [\u003c000000004376f706\u003e] chrdev_open+0x111/0x300 fs/char_dev.c:414\n    [\u003c00000000614d379f\u003e] do_dentry_open+0x2f9/0x750 fs/open.c:920\n    [\u003c000000008eb24774\u003e] do_open fs/namei.c:3636 [inline]\n    [\u003c000000008eb24774\u003e] path_openat+0x143f/0x1a30 fs/namei.c:3791\n    [\u003c00000000955077b5\u003e] do_filp_open+0xce/0x1c0 fs/namei.c:3818\n    [\u003c00000000b78973b0\u003e] do_sys_openat2+0xf0/0x260 fs/open.c:1356\n    [\u003c00000000057be699\u003e] do_sys_open fs/open.c:1372 [inline]\n    [\u003c00000000057be699\u003e] __do_sys_openat fs/open.c:1388 [inline]\n    [\u003c00000000057be699\u003e] __se_sys_openat fs/open.c:1383 [inline]\n    [\u003c00000000057be699\u003e] __x64_sys_openat+0x83/0xf0 fs/open.c:1383\n    [\u003c00000000a7d2182d\u003e] do_syscall_x64 arch/x86/entry/common.c:50 [inline]\n    [\u003c00000000a7d2182d\u003e] do_syscall_64+0x3c/0x90 arch/x86/entry/common.c:80\n    [\u003c000000004cc4e8c4\u003e] entry_SYSCALL_64_after_hwframe+0x72/0xdc\n\nunreferenced object 0xffff88802f671700 (size 240):\n  comm \"syz-executor.1\", pid 33269, jiffies 4295743854 (age 18.736s)\n  hex dump (first 32 bytes):\n    68 c9 db 1e 80 88 ff ff 68 c9 db 1e 80 88 ff ff  h.......h.......\n    00 c0 7b 2f 80 88 ff ff 00 c8 db 1e 80 88 ff ff  ..{/............\n  backtrace:\n    [\u003c00000000e9d9fdb6\u003e] __alloc_skb+0x223/0x250 net/core/skbuff.c:644\n    [\u003c000000002c3e4e0b\u003e] alloc_skb include/linux/skbuff.h:1288 [inline]\n    [\u003c000000002c3e4e0b\u003e] alloc_skb_with_frags+0x6f/0x350 net/core/skbuff.c:6378\n    [\u003c00000000825f98d7\u003e] sock_alloc_send_pskb+0x3ac/0x3e0 net/core/sock.c:2729\n    [\u003c00000000e9eb3df3\u003e] tun_alloc_skb drivers/net/tun.c:1529 [inline]\n    [\u003c\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":"tun: Fix memory leak for detached NAPI queue.","id":"CVE-2023-53685","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":"linux:linux_kernel","products":["linux:linux_kernel"],"type":"denial_of_service","year":"2023"},"n_packages":0,"n_references":3,"next":{"headline":"net/handshake: fix null-ptr-deref in handshake_nl_done_doit()","id":"CVE-2023-53686"},"packages":[],"prev":{"headline":"xfrm: Zero padding when dumping algos and encap","id":"CVE-2023-53684"},"products":["Linux"],"published":"2025-10-07","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":null,"exploitation":null,"technical_impact":null},"state":"PUBLISHED","updated":"2026-05-11","vendors":["Linux"]},"summary":"A local attacker can cause a memory leak in the Linux kernel TUN driver by exploiting a race condition during queue detachment, leading to resource exhaustion.","url":"https://insights.sbomify.com/CVE-2023-53685/"}