Please pull this fix for a deadlock in the Yama LSM.
The following changes since commit d9875690d9b89a866022ff49e3fcea892345ad92:
Linus Torvalds (1):
Linux 3.6-rc2
are available in the git repository at:
git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security.git for-linus
Kees Cook (1):
Yama: access task_struct->comm directly
security/yama/yama_lsm.c | 10 ++--------
1 file changed, 2 insertions(+), 8 deletions(-)
commit 7612bfeecc197bbb6629842b5c6ff1967f0a9b70
Author: Kees Cook <[email protected]>
Date: Wed Aug 15 11:41:55 2012 -0700
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 <[email protected]>
Suggested-by: Oleg Nesterov <[email protected]>
CC: [email protected]
Signed-off-by: Kees Cook <[email protected]>
Acked-by: John Johansen <[email protected]>
Signed-off-by: James Morris <[email protected]>
diff --git a/security/yama/yama_lsm.c b/security/yama/yama_lsm.c
index d51b7c7..0cc99a3 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;