cbcvebase.
CVE-2022-50661
published 2025-12-09

CVE-2022-50661: In the Linux kernel, the following vulnerability has been resolved: seccomp: Move copy_seccomp() to no failure path. Our syzbot instance reported memory leaks…

PriorityP421low5.5
EPSS
0.24%
15.2th percentile
In the Linux kernel, the following vulnerability has been resolved: seccomp: Move copy_seccomp() to no failure path. Our syzbot instance reported memory leaks in do_seccomp() [0], similar to the report [1]. It shows that we miss freeing struct seccomp_filter and some objects included in it. We can reproduce the issue with the program below [2] which calls one seccomp() and two clone() syscalls. The first clone()d child exits earlier than its parent and sends a signal to kill it during the second clone(), more precisely before the fatal_signal_pending() test in copy_process(). When the parent receives the signal, it has to destroy the embryonic process and return -EINTR to user space. In the failure path, we have to call seccomp_filter_release() to decrement the filter's refcount. Initially, we called it in free_task() called from the failure path, but the commit 3a15fb6ed92c ("seccomp: release filter after task is fully dead") moved it to release_task() to notify user space as early as possible that the filter is no longer used. To keep the change and current seccomp refcount semantics, let's move copy_seccomp() just after the signal check and add a WARN_ON_ONCE() in free_task() for future debugging. [0]: unreferenced object 0xffff8880063add00 (size 256): comm "repro_seccomp", pid 230, jiffies 4294687090 (age 9.914s) hex dump (first 32 bytes): 01 00 00 00 01 00 00 00 00 00 00 00 00 00 00 00 ................ ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ................ backtrace: 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) do_syscall_64 (arch/x86/entry/common.c:50 arch/x86/entry/common.c:80) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:120) unreferenced object 0xffffc90000035000 (size 4096): comm "repro_seccomp", pid 230, jiffies 4294687090 (age 9.915s) hex dump (first 32 bytes): 01 00 00 00 00 00 00 00 00 00 00 00 05 00 00 00 ..........

Affected

15 ranges
VendorProductVersion rangeFixed in
debianlinux< linux 6.1.4-1 (bookworm)linux 6.1.4-1 (bookworm)
linuxlinux
linuxlinux>= 3a15fb6ed92cb32b0a83f406aa4a96f28c9adbc3 < d4a895e924b486f2a38463114509e1088ef4d7f5d4a895e924b486f2a38463114509e1088ef4d7f5
linuxlinux>= 3a15fb6ed92cb32b0a83f406aa4a96f28c9adbc3 < a31a647a3d1073a642c5bbe3457731fb353cb980a31a647a3d1073a642c5bbe3457731fb353cb980
linuxlinux>= 3a15fb6ed92cb32b0a83f406aa4a96f28c9adbc3 < 29a69fa075d0577eff1137426669de21187ec18229a69fa075d0577eff1137426669de21187ec182
linuxlinux>= 3a15fb6ed92cb32b0a83f406aa4a96f28c9adbc3 < 5b81f0c6c60e35bf8153230ddfb03ebb14e179865b81f0c6c60e35bf8153230ddfb03ebb14e17986
linuxlinux>= 3a15fb6ed92cb32b0a83f406aa4a96f28c9adbc3 < a1140cb215fa13dcec06d12ba0c3ee105633b7c4a1140cb215fa13dcec06d12ba0c3ee105633b7c4
linuxlinux_kernel>= 0 < 5.10.191-15.10.191-1
linuxlinux_kernel>= 0 < 6.1.4-16.1.4-1
linuxlinux_kernel>= 0 < 6.1.4-16.1.4-1
linuxlinux_kernel>= 0 < 6.1.4-16.1.4-1
linuxlinux_kernel>= 5.11.0 < 5.15.865.15.86
linuxlinux_kernel>= 5.16.0 < 6.0.166.0.16
linuxlinux_kernel>= 5.9.0 < 5.10.1805.10.180
linuxlinux_kernel>= 6.1.0 < 6.1.26.1.2
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