path: root/Documentation/security/Yama.txt
diff options
authorKees Cook <keescook@chromium.org>2012-02-14 16:48:09 -0800
committerJames Morris <jmorris@namei.org>2012-02-16 10:25:18 +1100
commitbf06189e4d14641c0148bea16e9dd24943862215 (patch)
tree5c62eb24339041baf65b8e42daac42c7a01efc0e /Documentation/security/Yama.txt
parent3ab1aff89477dafb1aaeafe8c8669114a02b7226 (diff)
For a process to entirely disable Yama ptrace restrictions, it can use the special PR_SET_PTRACER_ANY pid to indicate that any otherwise allowed process may ptrace it. This is stronger than calling PR_SET_PTRACER with pid "1" because it includes processes in external pid namespaces. This is currently needed by the Chrome renderer, since its crash handler (Breakpad) runs external to the renderer's pid namespace. Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: James Morris <jmorris@namei.org>
Diffstat (limited to 'Documentation/security/Yama.txt')
1 files changed, 6 insertions, 1 deletions
diff --git a/Documentation/security/Yama.txt b/Documentation/security/Yama.txt
index 4f0b7896a21d..a9511f179069 100644
--- a/Documentation/security/Yama.txt
+++ b/Documentation/security/Yama.txt
@@ -41,7 +41,12 @@ other process (and its descendents) are allowed to call PTRACE_ATTACH
against it. Only one such declared debugging process can exists for
each inferior at a time. For example, this is used by KDE, Chromium, and
Firefox's crash handlers, and by Wine for allowing only Wine processes
-to ptrace each other.
+to ptrace each other. If a process wishes to entirely disable these ptrace
+restrictions, it can call prctl(PR_SET_PTRACER, PR_SET_PTRACER_ANY, ...)
+so that any otherwise allowed process (even those in external pid namespaces)
+may attach.
+The sysctl settings are:
0 - classic ptrace permissions: a process can PTRACE_ATTACH to any other
process running under the same uid, as long as it is dumpable (i.e.

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