{"cve":"CVE-2022-50661","nvd":{"published":"2025-12-09T16:17:17.757","modified":"2026-06-17T05:23:57.167","status":"Deferred","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nseccomp: Move copy_seccomp() to no failure path.\n\nOur syzbot instance reported memory leaks in do_seccomp() [0], similar\nto the report [1].  It shows that we miss freeing struct seccomp_filter\nand some objects included in it.\n\nWe can reproduce the issue with the program below [2] which calls one\nseccomp() and two clone() syscalls.\n\nThe first clone()d child exits earlier than its parent and sends a\nsignal to kill it during the second clone(), more precisely before the\nfatal_signal_pending() test in copy_process().  When the parent receives\nthe signal, it has to destroy the embryonic process and return -EINTR to\nuser space.  In the failure path, we have to call seccomp_filter_release()\nto decrement the filter's refcount.\n\nInitially, we called it in free_task() called from the failure path, but\nthe commit 3a15fb6ed92c (\"seccomp: release filter after task is fully\ndead\") moved it to release_task() to notify user space as early as possible\nthat the filter is no longer used.\n\nTo keep the change and current seccomp refcount semantics, let's move\ncopy_seccomp() just after the signal check and add a WARN_ON_ONCE() in\nfree_task() for future debugging.\n\n[0]:\nunreferenced object 0xffff8880063add00 (size 256):\n  comm \"repro_seccomp\", pid 230, jiffies 4294687090 (age 9.914s)\n  hex dump (first 32 bytes):\n    01 00 00 00 01 00 00 00 00 00 00 00 00 00 00 00  ................\n    ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff  ................\n  backtrace:\n    do_seccomp (./include/linux/slab.h:600 ./include/linux/slab.h:733 kernel/seccomp.c:666 kernel/seccomp.c:708 kernel/seccomp.c:1871 kernel/seccomp.c:1991)\n    do_syscall_64 (arch/x86/entry/common.c:50 arch/x86/entry/common.c:80)\n    entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:120)\nunreferenced object 0xffffc90000035000 (size 4096):\n  comm \"repro_seccomp\", pid 230, jiffies 4294687090 (age 9.915s)\n  hex dump (first 32 bytes):\n    01 00 00 00 00 00 00 00 00 00 00 00 05 00 00 00  ................\n    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................\n  backtrace:\n    __vmalloc_node_range (mm/vmalloc.c:3226)\n    __vmalloc_node (mm/vmalloc.c:3261 (discriminator 4))\n    bpf_prog_alloc_no_stats (kernel/bpf/core.c:91)\n    bpf_prog_alloc (kernel/bpf/core.c:129)\n    bpf_prog_create_from_user (net/core/filter.c:1414)\n    do_seccomp (kernel/seccomp.c:671 kernel/seccomp.c:708 kernel/seccomp.c:1871 kernel/seccomp.c:1991)\n    do_syscall_64 (arch/x86/entry/common.c:50 arch/x86/entry/common.c:80)\n    entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:120)\nunreferenced object 0xffff888003fa1000 (size 1024):\n  comm \"repro_seccomp\", pid 230, jiffies 4294687090 (age 9.915s)\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 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................\n  backtrace:\n    bpf_prog_alloc_no_stats (./include/linux/slab.h:600 ./include/linux/slab.h:733 kernel/bpf/core.c:95)\n    bpf_prog_alloc (kernel/bpf/core.c:129)\n    bpf_prog_create_from_user (net/core/filter.c:1414)\n    do_seccomp (kernel/seccomp.c:671 kernel/seccomp.c:708 kernel/seccomp.c:1871 kernel/seccomp.c:1991)\n    do_syscall_64 (arch/x86/entry/common.c:50 arch/x86/entry/common.c:80)\n    entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:120)\nunreferenced object 0xffff888006360240 (size 16):\n  comm \"repro_seccomp\", pid 230, jiffies 4294687090 (age 9.915s)\n  hex dump (first 16 bytes):\n    01 00 37 00 76 65 72 6c e0 83 01 06 80 88 ff ff  ..7.verl........\n  backtrace:\n    bpf_prog_store_orig_filter (net/core/filter.c:1137)\n    bpf_prog_create_from_user (net/core/filter.c:1428)\n    do_seccomp (kernel/seccomp.c:671 kernel/seccomp.c:708 kernel/seccomp.c:1871 kernel/seccomp.c:1991)\n    do_syscall_64 (arch/x86/entry/common.c:50 arch/x86/entry/common.c:80)\n    entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:120)\nunreferenced object 0xffff888\n---truncated---","cvss_v4":null,"cvss_v3":null,"cwes":[],"references":["https://git.kernel.org/stable/c/29a69fa075d0577eff1137426669de21187ec182","https://git.kernel.org/stable/c/5b81f0c6c60e35bf8153230ddfb03ebb14e17986","https://git.kernel.org/stable/c/a1140cb215fa13dcec06d12ba0c3ee105633b7c4","https://git.kernel.org/stable/c/a31a647a3d1073a642c5bbe3457731fb353cb980","https://git.kernel.org/stable/c/d4a895e924b486f2a38463114509e1088ef4d7f5"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:16:40.427100871+00:00"},"epss":{"cve":"CVE-2022-50661","score":0.00244,"percentile":0.1568,"date":"2026-10-31"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}