svn commit: r230583 - head/sys/kern

[Gleb Smirnoff]

Author: glebius
Date: Thu Jan 26 11:59:48 2012
New Revision: 230583
URL: http://svn.freebsd.org/changeset/base/230583

Log:
  Although aio_nbytes is size_t, later is is signed to
  casted types: to ssize_t in filesystem code and to
  int in buf code, thus supplying a negative argument
  leads to kernel panic later. To fix that check user
  supplied argument in the beginning of syscall.
  
  Submitted by:	Maxim Dounin <mdounin mdounin.ru>, maxim@

Modified:
  head/sys/kern/vfs_aio.c

Modified: head/sys/kern/vfs_aio.c
==============================================================================
--- head/sys/kern/vfs_aio.c	Thu Jan 26 11:15:12 2012	(r230582)
+++ head/sys/kern/vfs_aio.c	Thu Jan 26 11:59:48 2012	(r230583)
@@ -1552,6 +1552,12 @@ aio_aqueue(struct thread *td, struct aio
 		return (error);
 	}
 
+	/* XXX: aio_nbytes is later casted to signed types. */
+	if ((int)aiocbe->uaiocb.aio_nbytes < 0) {
+		uma_zfree(aiocb_zone, aiocbe);
+		return (EINVAL);
+	}
+
 	if (aiocbe->uaiocb.aio_sigevent.sigev_notify != SIGEV_KEVENT &&
 	    aiocbe->uaiocb.aio_sigevent.sigev_notify != SIGEV_SIGNAL &&
 	    aiocbe->uaiocb.aio_sigevent.sigev_notify != SIGEV_THREAD_ID &&