diff options
| author | Mathieu Desnoyers | 2013-06-28 09:49:46 -0400 |
|---|---|---|
| committer | Linus Torvalds | 2013-06-29 11:29:08 -0700 |
| commit | 706b23bde27a391f0974df2a8351661770fa2e07 (patch) | |
| tree | 2b8d6be33dda49dcfc9ed8a5a688db4e8f56ac4c | |
| parent | bd2931b5cff6a3bf39bfe15fae051fb8229c0029 (diff) | |
Fix: kernel/ptrace.c: ptrace_peek_siginfo() missing __put_user() validation
This __put_user() could be used by unprivileged processes to write into
kernel memory. The issue here is that even if copy_siginfo_to_user()
fails, the error code is not checked before __put_user() is executed.
Luckily, ptrace_peek_siginfo() has been added within the 3.10-rc cycle,
so it has not hit a stable release yet.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Cc: Andrey Vagin <avagin@openvz.org>
Cc: Roland McGrath <roland@redhat.com>
Cc: Paul McKenney <paulmck@linux.vnet.ibm.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Dave Jones <davej@redhat.com>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Pedro Alves <palves@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | kernel/ptrace.c | 20 |
1 files changed, 11 insertions, 9 deletions
diff --git a/kernel/ptrace.c b/kernel/ptrace.c index aed981a3f69c..335a7ae697f5 100644 --- a/kernel/ptrace.c +++ b/kernel/ptrace.c @@ -665,20 +665,22 @@ static int ptrace_peek_siginfo(struct task_struct *child, if (unlikely(is_compat_task())) { compat_siginfo_t __user *uinfo = compat_ptr(data); - ret = copy_siginfo_to_user32(uinfo, &info); - ret |= __put_user(info.si_code, &uinfo->si_code); + if (copy_siginfo_to_user32(uinfo, &info) || + __put_user(info.si_code, &uinfo->si_code)) { + ret = -EFAULT; + break; + } + } else #endif { siginfo_t __user *uinfo = (siginfo_t __user *) data; - ret = copy_siginfo_to_user(uinfo, &info); - ret |= __put_user(info.si_code, &uinfo->si_code); - } - - if (ret) { - ret = -EFAULT; - break; + if (copy_siginfo_to_user(uinfo, &info) || + __put_user(info.si_code, &uinfo->si_code)) { + ret = -EFAULT; + break; + } } data += sizeof(siginfo_t); |