aboutsummaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorMathieu Desnoyers <mathieu.desnoyers@efficios.com>2013-06-28 09:49:46 -0400
committerLinus Torvalds <torvalds@linux-foundation.org>2013-06-29 11:29:08 -0700
commit706b23bde27a391f0974df2a8351661770fa2e07 (patch)
tree2b8d6be33dda49dcfc9ed8a5a688db4e8f56ac4c
parentbd2931b5cff6a3bf39bfe15fae051fb8229c0029 (diff)
downloadlinux-linaro-stable-706b23bde27a391f0974df2a8351661770fa2e07.tar.gz
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.c20
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);