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authorKees Cook <keescook@chromium.org>2012-08-15 11:41:55 -0700
committerJames Morris <james.l.morris@oracle.com>2012-08-17 20:40:38 +1000
commit7612bfeecc197bbb6629842b5c6ff1967f0a9b70 (patch)
treed73acd2bc97866b256a70acb83e4ca69bce6e32d /security/yama
parentd9875690d9b89a866022ff49e3fcea892345ad92 (diff)
downloadvexpress-lsk-7612bfeecc197bbb6629842b5c6ff1967f0a9b70.tar.gz
Yama: access task_struct->comm directly
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> CC: stable@vger.kernel.org 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>
Diffstat (limited to 'security/yama')
-rw-r--r--security/yama/yama_lsm.c10
1 files changed, 2 insertions, 8 deletions
diff --git a/security/yama/yama_lsm.c b/security/yama/yama_lsm.c
index d51b7c76c37..0cc99a3ea42 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;