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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2012-08-12 20:36:13 +0200 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2012-08-12 20:36:13 +0200 |
| commit | c8dfbf48d3dd4e96044f2fa04fb5f58239e44c31 (patch) | |
| tree | 822ae29c1572f7e95fd4726c3effd8389a79b336 /Documentation | |
| parent | Merge tag 'pm-for-3.6-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/r... (diff) | |
| parent | Yama: higher restrictions should block PTRACE_TRACEME (diff) | |
| download | linux-c8dfbf48d3dd4e96044f2fa04fb5f58239e44c31.tar.xz linux-c8dfbf48d3dd4e96044f2fa04fb5f58239e44c31.zip | |
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security
Pull a security subsystem fix from James Morris
"This fixes an issue in the Yama LSM"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security:
Yama: higher restrictions should block PTRACE_TRACEME
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/security/Yama.txt | 14 |
1 files changed, 7 insertions, 7 deletions
diff --git a/Documentation/security/Yama.txt b/Documentation/security/Yama.txt index e369de2d48cd..dd908cf64ecf 100644 --- a/Documentation/security/Yama.txt +++ b/Documentation/security/Yama.txt @@ -46,14 +46,13 @@ 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. -These restrictions do not change how ptrace via PTRACE_TRACEME operates. - -The sysctl settings are: +The sysctl settings (writable only with CAP_SYS_PTRACE) 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. did not transition uids, start privileged, or have called - prctl(PR_SET_DUMPABLE...) already). + prctl(PR_SET_DUMPABLE...) already). Similarly, PTRACE_TRACEME is + unchanged. 1 - restricted ptrace: a process must have a predefined relationship with the inferior it wants to call PTRACE_ATTACH on. By default, @@ -61,12 +60,13 @@ The sysctl settings are: classic criteria is also met. To change the relationship, an inferior can call prctl(PR_SET_PTRACER, debugger, ...) to declare an allowed debugger PID to call PTRACE_ATTACH on the inferior. + Using PTRACE_TRACEME is unchanged. 2 - admin-only attach: only processes with CAP_SYS_PTRACE may use ptrace - with PTRACE_ATTACH. + with PTRACE_ATTACH, or through children calling PTRACE_TRACEME. -3 - no attach: no processes may use ptrace with PTRACE_ATTACH. Once set, - this sysctl cannot be changed to a lower value. +3 - no attach: no processes may use ptrace with PTRACE_ATTACH nor via + PTRACE_TRACEME. Once set, this sysctl value cannot be changed. The original children-only logic was based on the restrictions in grsecurity. |