From: Greg KH <[email protected]> 3.5-stable review patch. If anyone has any objections, please let me know.
------------------ From: Kees Cook <[email protected]> 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 <[email protected]> Suggested-by: Oleg Nesterov <[email protected]> Signed-off-by: Kees Cook <[email protected]> Acked-by: John Johansen <[email protected]> Signed-off-by: James Morris <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- security/yama/yama_lsm.c | 10 ++-------- 1 file changed, 2 insertions(+), 8 deletions(-) --- a/security/yama/yama_lsm.c +++ b/security/yama/yama_lsm.c @@ -279,12 +279,9 @@ static int yama_ptrace_access_check(stru } 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 ta } 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; -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
