Description

In the Linux kernel, the following vulnerability has been resolved: seccomp: passthrough uretprobe systemcall without filtering When attaching uretprobes to processes running inside docker, the attached process is segfaulted when encountering the retprobe. The reason is that now that uretprobe is a system call the default seccomp filters in docker block it as they only allow a specific set of known syscalls. This is true for other userspace applications which use seccomp to control their syscall surface. Since uretprobe is a "kernel implementation detail" system call which is not used by userspace application code directly, it is impractical and there's very little point in forcing all userspace applications to explicitly allow it in order to avoid crashing tracked processes. Pass this systemcall through seccomp without depending on configuration. Note: uretprobe is currently only x86_64 and isn't expected to ever be supported in i386. [kees: minimized changes for easier backporting, tweaked commit log]

Affected Products 3

References 3

• git.kernel.org https://git.kernel.org/stable/c/5a262628f4cf2437d863fe41f9d427177b87664c
  Patch
• git.kernel.org https://git.kernel.org/stable/c/cf6cb56ef24410fb5308f9655087f1eddf4452e6
  Patch
• git.kernel.org https://git.kernel.org/stable/c/fa80018aa5be10c35e9fa896b7b4061a8dce3eed
  Patch

Remediation

• git.kernel.org https://git.kernel.org/stable/c/5a262628f4cf2437d863fe41f9d427177b87664c
  Patch
• git.kernel.org https://git.kernel.org/stable/c/cf6cb56ef24410fb5308f9655087f1eddf4452e6
  Patch
• git.kernel.org https://git.kernel.org/stable/c/fa80018aa5be10c35e9fa896b7b4061a8dce3eed
  Patch