diff options
| author | Kees Cook <keescook@chromium.org> | 2012-08-15 11:41:55 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2012-08-25 19:31:41 -0700 |
| commit | 67dd44b1ec0de935b8ad962e00ee8da44d67fc28 (patch) | |
| tree | 483e7dbc36db4036b756f84d48a34c1e1bf4af20 | |
| parent | 2069c08ae4d4c75582b7ed2ddd60fc3c32dfde15 (diff) | |
Yama: access task_struct->comm directly
commit 7612bfeecc197bbb6629842b5c6ff1967f0a9b70 upstream.
The core ptrace access checking routine holds a task lock, and when
reporting a failure, Yama takes a separate task lock. To avoid a
potential deadlock with two ptracers taking the opposite locks, do not
use get_task_comm() and just use ->comm directly since accuracy is not
important for the report.
Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Suggested-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | security/yama/yama_lsm.c | 10 |
1 files changed, 2 insertions, 8 deletions
diff --git a/security/yama/yama_lsm.c b/security/yama/yama_lsm.c index d51b7c76c37d..0cc99a3ea42d 100644 --- a/security/yama/yama_lsm.c +++ b/security/yama/yama_lsm.c @@ -279,12 +279,9 @@ static int yama_ptrace_access_check(struct task_struct *child, } if (rc) { - char name[sizeof(current->comm)]; printk_ratelimited(KERN_NOTICE "ptrace of pid %d was attempted by: %s (pid %d)\n", - child->pid, - get_task_comm(name, current), - current->pid); + child->pid, current->comm, current->pid); } return rc; @@ -319,12 +316,9 @@ static int yama_ptrace_traceme(struct task_struct *parent) } if (rc) { - char name[sizeof(current->comm)]; printk_ratelimited(KERN_NOTICE "ptraceme of pid %d was attempted by: %s (pid %d)\n", - current->pid, - get_task_comm(name, parent), - parent->pid); + current->pid, parent->comm, parent->pid); } return rc; |