diff options
author | Mark Grondona <mgrondona@llnl.gov> | 2013-09-11 14:24:31 -0700 |
---|---|---|
committer | Wolfgang Wiedmeyer <wolfgit@wiedmeyer.de> | 2016-03-18 01:51:05 +0100 |
commit | 11415a5dae1588cadeeeb9134eb714f224484301 (patch) | |
tree | d6c0177f87adfac51ab181742032f683d2266eae | |
parent | 6403969ee2e248b81a8c2ca7a6138e92ab837c3d (diff) | |
download | kernel_samsung_smdk4412-11415a5dae1588cadeeeb9134eb714f224484301.zip kernel_samsung_smdk4412-11415a5dae1588cadeeeb9134eb714f224484301.tar.gz kernel_samsung_smdk4412-11415a5dae1588cadeeeb9134eb714f224484301.tar.bz2 |
__ptrace_may_access() should not deny sub-threads
commit 73af963f9f3036dffed55c3a2898598186db1045 upstream.
__ptrace_may_access() checks get_dumpable/ptrace_has_cap/etc if task !=
current, this can can lead to surprising results.
For example, a sub-thread can't readlink("/proc/self/exe") if the
executable is not readable. setup_new_exec()->would_dump() notices that
inode_permission(MAY_READ) fails and then it does
set_dumpable(suid_dumpable). After that get_dumpable() fails.
(It is not clear why proc_pid_readlink() checks get_dumpable(), perhaps we
could add PTRACE_MODE_NODUMPABLE)
Change __ptrace_may_access() to use same_thread_group() instead of "task
== current". Any security check is pointless when the tasks share the
same ->mm.
Change-Id: Ib6ca927a1eb0637df8030aabcb3129d5be343512
Signed-off-by: Mark Grondona <mgrondona@llnl.gov>
Signed-off-by: Ben Woodard <woodard@redhat.com>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r-- | kernel/ptrace.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/kernel/ptrace.c b/kernel/ptrace.c index 40581ee..8381d15 100644 --- a/kernel/ptrace.c +++ b/kernel/ptrace.c @@ -182,7 +182,7 @@ int __ptrace_may_access(struct task_struct *task, unsigned int mode) */ int dumpable = 0; /* Don't let security modules deny introspection */ - if (task == current) + if (same_thread_group(task, current)) return 0; rcu_read_lock(); tcred = __task_cred(task); |