leandrof/linux
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

ptrace: Move setting/clearing ptrace_message into ptrace_stop

Browse Source 
Today ptrace_message is easy to overlook as it not a core part of
ptrace_stop.  It has been overlooked so much that there are places
that set ptrace_message and don't clear it, and places that never set
it.  So if you get an unlucky sequence of events the ptracer may be
able to read a ptrace_message that does not apply to the current
ptrace stop.

Move setting of ptrace_message into ptrace_stop so that it always gets
set before the stop, and always gets cleared after the stop.  This
prevents non-sense from being reported to userspace and makes
ptrace_message more visible in the ptrace helper functions so that
kernel developers can see it.

Link: https://lkml.kernel.org/r/87bky67qfv.fsf_-_@email.froward.int.ebiederm.org
Acked-by: Oleg Nesterov <oleg@redhat.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
This commit is contained in:
Eric W. Biederman
2022-01-27 12:15:32 -06:00
parent 355f841a3f
commit 336d4b814b
3 changed files with 16 additions and 16 deletions
Download Patch File Download Diff File Expand all files Collapse all files

2
include/uapi/linux/ptrace.h
View File

@@ -114,7 +114,7 @@ struct ptrace_rseq_configuration {
/*
* These values are stored in task->ptrace_message
* by ptrace_report_syscall_* to describe the current syscall-stop.
* by ptrace_stop to describe the current syscall-stop.
*/
#define PTRACE_EVENTMSG_SYSCALL_ENTRY 1
#define PTRACE_EVENTMSG_SYSCALL_EXIT 2