security: let security modules use PTRACE_MODE_* with bitmasks

It looks like smack and yama weren't aware that the ptrace mode
can have flags ORed into it - PTRACE_MODE_NOAUDIT until now, but
only for /proc/$pid/stat, and with the PTRACE_MODE_*CREDS patch,
all modes have flags ORed into them.

Signed-off-by: Jann Horn <jann@thejh.net>
Acked-by: Kees Cook <keescook@chromium.org>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Morris <james.l.morris@oracle.com>
Cc: "Serge E. Hallyn" <serge.hallyn@ubuntu.com>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Willy Tarreau <w@1wt.eu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Jann Horn 2016-01-20 15:00:01 -08:00 committed by Linus Torvalds
parent 570ac9337b
commit 3dfb7d8cdb
2 changed files with 5 additions and 7 deletions

View File

@ -398,12 +398,10 @@ static int smk_copy_relabel(struct list_head *nhead, struct list_head *ohead,
*/
static inline unsigned int smk_ptrace_mode(unsigned int mode)
{
switch (mode) {
case PTRACE_MODE_READ:
return MAY_READ;
case PTRACE_MODE_ATTACH:
if (mode & PTRACE_MODE_ATTACH)
return MAY_READWRITE;
}
if (mode & PTRACE_MODE_READ)
return MAY_READ;
return 0;
}

View File

@ -281,7 +281,7 @@ static int yama_ptrace_access_check(struct task_struct *child,
int rc = 0;
/* require ptrace target be a child of ptracer on attach */
if (mode == PTRACE_MODE_ATTACH) {
if (mode & PTRACE_MODE_ATTACH) {
switch (ptrace_scope) {
case YAMA_SCOPE_DISABLED:
/* No additional restrictions. */
@ -307,7 +307,7 @@ static int yama_ptrace_access_check(struct task_struct *child,
}
}
if (rc) {
if (rc && (mode & PTRACE_MODE_NOAUDIT) == 0) {
printk_ratelimited(KERN_NOTICE
"ptrace of pid %d was attempted by: %s (pid %d)\n",
child->pid, current->comm, current->pid);