Jann Horn 5a41a3033a ptrace: Check PTRACE_O_SUSPEND_SECCOMP permission on PTRACE_SEIZE
commit ee1fee9005 upstream.

Setting PTRACE_O_SUSPEND_SECCOMP is supposed to be a highly privileged
operation because it allows the tracee to completely bypass all seccomp
filters on kernels with CONFIG_CHECKPOINT_RESTORE=y. It is only supposed to
be settable by a process with global CAP_SYS_ADMIN, and only if that
process is not subject to any seccomp filters at all.

However, while these permission checks were done on the PTRACE_SETOPTIONS
path, they were missing on the PTRACE_SEIZE path, which also sets
user-specified ptrace flags.

Move the permissions checks out into a helper function and let both
ptrace_attach() and ptrace_setoptions() call it.

Cc: stable@kernel.org
Fixes: 13c4a90119 ("seccomp: add ptrace options for suspend/resume")
Signed-off-by: Jann Horn <jannh@google.com>
Link: https://lkml.kernel.org/r/20220319010838.1386861-1-jannh@google.com
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-08 14:39:50 +02:00
2022-03-28 09:57:11 +02:00

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