{"answers":{"affected":"It affects 1 product.","exploited":"There is no known exploitation of CVE-2026-52946 in the wild and no public exploit code.","fix":"Apply the vendor's patch.","what":"CVE-2026-52946 is a high-severity vulnerability in Linux kernel, published on 24 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim."},"fix_prompt":"Check this codebase for CVE-2026-52946 and fix it if it is affected.\n\nWhat it is: CVE-2026-52946 is a high-severity vulnerability in Linux kernel, published on 24 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.\nExploitation: There is no known exploitation of CVE-2026-52946 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-2026-52946/ (Markdown: https://insights.sbomify.com/CVE-2026-52946/index.md)","id":"CVE-2026-52946","markdown":"https://insights.sbomify.com/CVE-2026-52946/index.md","name":"CVE-2026-52946","record":{"aliases":["AZL-90684","BELL-CVE-2026-52946","DEBIAN-CVE-2026-52946","GHSA-9h35-hqff-9v3w","ROOT-OS-DEBIAN-11-CVE-2026-52946","ROOT-OS-DEBIAN-12-CVE-2026-52946","ROOT-OS-UBUNTU-2204-CVE-2026-52946","ROOT-OS-UBUNTU-2404-CVE-2026-52946","UBUNTU-CVE-2026-52946"],"analysis":{"component_type":"kernel","fix_type":"patch","impacts":["denial_of_service"],"network_reachable":"yes","non_default_config":false,"product_category":"Linux kernel","requires_auth":"none","summary":"A race condition in Linux kernel fasync signaling can cause a deadlock, leading to denial of service via TCP URG packets.","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":7.5,"severity":"high","source":"cna","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","version":"3.1"},"cwes":[{"id":"CWE-667","name":"Improper Locking"},{"id":"CWE-362","name":"Concurrent Execution using Shared Resource with Improper Synchronization"}],"description":"In the Linux kernel, the following vulnerability has been resolved:\n\nfs/fcntl: fix SOFTIRQ-unsafe lock order in fasync signaling\n\nA SOFTIRQ-safe to SOFTIRQ-unsafe lock order deadlock can occur in\nsend_sigio() and send_sigurg() when a process group receives a signal.\n\nWhen FASYNC is configured for a process group (PIDTYPE_PGID), both\nfunctions use read_lock(\u0026tasklist_lock) to traverse the task list.\nHowever, they are frequently called from softirq context:\n- send_sigio() via input_inject_event -\u003e kill_fasync\n- send_sigurg() via tcp_check_urg -\u003e sk_send_sigurg (NET_RX_SOFTIRQ)\n\nThe deadlock is caused by the rwlock writer fairness mechanism:\n1. CPU 0 (process context) holds read_lock(\u0026tasklist_lock) in do_wait().\n2. CPU 1 (process context) attempts write_lock(\u0026tasklist_lock) in\n   fork() or exit() and spins, which blocks all new readers.\n3. CPU 0 is interrupted by a softirq (e.g., TCP URG packet reception).\n4. The softirq calls send_sigurg() and attempts to acquire\n   read_lock(\u0026tasklist_lock), deadlocking because CPU 1 is waiting.\n\nSince PID hashing and do_each_pid_task() traversals are already\nRCU-protected, the read_lock on tasklist_lock is no longer strictly\nrequired for safe traversal. Fix this by replacing tasklist_lock with\nrcu_read_lock(), aligning the process group signaling path with the\nsingle-PID path. This also mitigates a potential remote denial of\nservice vector via TCP URG packets.\n\nLockdep splat:\n=====================================================\nWARNING: SOFTIRQ-safe -\u003e SOFTIRQ-unsafe lock order detected\n[...]\nChain exists of:\n  \u0026dev-\u003eevent_lock --\u003e \u0026f_owner-\u003elock --\u003e tasklist_lock\n\nPossible interrupt unsafe locking scenario:\n       CPU0                    CPU1\n       ----                    ----\n  lock(tasklist_lock);\n                           local_irq_disable();\n                           lock(\u0026dev-\u003eevent_lock);\n                           lock(\u0026f_owner-\u003elock);\n  \u003cInterrupt\u003e\n    lock(\u0026dev-\u003eevent_lock);\n\n*** DEADLOCK ***","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":"fs/fcntl: fix SOFTIRQ-unsafe lock order in fasync signaling","id":"CVE-2026-52946","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":"linux:linux_kernel","products":["linux:linux_kernel"],"type":"race_condition","year":"2026"},"n_packages":0,"n_references":9,"next":{"headline":"net: qrtr: fix refcount saturation and potential UAF in qrtr_port_remove","id":"CVE-2026-52947"},"packages":[],"prev":{"headline":"Revert \"wireguard: device: enable threaded NAPI\"","id":"CVE-2026-52945"},"products":["Linux"],"published":"2026-06-24","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":"yes","exploitation":"none","technical_impact":"partial"},"state":"PUBLISHED","updated":"2026-10-19","vendors":["Linux"]},"summary":"A race condition in Linux kernel fasync signaling can cause a deadlock, leading to denial of service via TCP URG packets.","url":"https://insights.sbomify.com/CVE-2026-52946/"}