The latest change of compat_sys_sigpending in commit
8f13621abced
("sigpending(): move compat to native") has broken it in two ways.
First, it tries to write 4 bytes more than userspace expects:
sizeof(old_sigset_t) == sizeof(long) == 8 instead of
sizeof(compat_old_sigset_t) == sizeof(u32) == 4.
Second, on big endian architectures these bytes are being written in the
wrong order.
This bug was found by strace test suite.
Reported-by: Anatoly Pugachev <matorola@gmail.com>
Inspired-by: Eugene Syromyatnikov <evgsyr@gmail.com>
Fixes: 8f13621abced ("sigpending(): move compat to native")
Signed-off-by: Dmitry V. Levin <ldv@altlinux.org>
Acked-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
#ifdef CONFIG_COMPAT
COMPAT_SYSCALL_DEFINE1(sigpending, compat_old_sigset_t __user *, set32)
{
+#ifdef __BIG_ENDIAN
sigset_t set;
- int err = do_sigpending(&set, sizeof(old_sigset_t));
- if (err == 0)
- if (copy_to_user(set32, &set, sizeof(old_sigset_t)))
- err = -EFAULT;
+ int err = do_sigpending(&set, sizeof(set.sig[0]));
+ if (!err)
+ err = put_user(set.sig[0], set32);
return err;
+#else
+ return sys_rt_sigpending((sigset_t __user *)set32, sizeof(*set32));
+#endif
}
#endif