add fortified implementations of pread/pread64

Change-Id: Iec39c3917e0bc94371bd81541619392f5abe29b9

4 files changed, 155 insertions, 0 deletions

diff --git a/libc/Android.mk b/libc/Android.mk
index e06a860..9d3b62a 100644
--- a/libc/Android.mk
+++ b/libc/Android.mk
@@ -71,6 +71,8 @@ libc_common_src_files += \
     bionic/__fgets_chk.cpp \
     bionic/__memmove_chk.cpp \
     bionic/__poll_chk.cpp \
+    bionic/__pread64_chk.cpp \
+    bionic/__pread_chk.cpp \
     bionic/__read_chk.cpp \
     bionic/__recvfrom_chk.cpp \
     bionic/__stpcpy_chk.cpp \
diff --git a/libc/bionic/__pread64_chk.cpp b/libc/bionic/__pread64_chk.cpp
new file mode 100644
index 0000000..5d6ad2d
--- /dev/null
+++ b/libc/bionic/__pread64_chk.cpp
@@ -0,0 +1,43 @@
+/*
+ * Copyright (C) 2015 The Android Open Source Project
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *  * Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  * Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#undef _FORTIFY_SOURCE
+#include <unistd.h>
+#include "private/libc_logging.h"
+
+extern "C" ssize_t __pread64_chk(int fd, void* buf, size_t count, off64_t offset, size_t buf_size) {
+  if (__predict_false(count > buf_size)) {
+    __fortify_chk_fail("pread64: prevented write past end of buffer", 0);
+  }
+
+  if (__predict_false(count > SSIZE_MAX)) {
+    __fortify_chk_fail("pread64: count > SSIZE_MAX", 0);
+  }
+
+  return pread64(fd, buf, count, offset);
+}
diff --git a/libc/bionic/__pread_chk.cpp b/libc/bionic/__pread_chk.cpp
new file mode 100644
index 0000000..7109ce6
--- /dev/null
+++ b/libc/bionic/__pread_chk.cpp
@@ -0,0 +1,43 @@
+/*
+ * Copyright (C) 2015 The Android Open Source Project
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *  * Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  * Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#undef _FORTIFY_SOURCE
+#include <unistd.h>
+#include "private/libc_logging.h"
+
+extern "C" ssize_t __pread_chk(int fd, void* buf, size_t count, off_t offset, size_t buf_size) {
+  if (__predict_false(count > buf_size)) {
+    __fortify_chk_fail("pread: prevented write past end of buffer", 0);
+  }
+
+  if (__predict_false(count > SSIZE_MAX)) {
+    __fortify_chk_fail("pread: count > SSIZE_MAX", 0);
+  }
+
+  return pread(fd, buf, count, offset);
+}
diff --git a/libc/include/unistd.h b/libc/include/unistd.h
index 92d3abe..a601cb7 100644
--- a/libc/include/unistd.h
+++ b/libc/include/unistd.h
@@ -224,6 +224,16 @@ extern int   tcsetpgrp(int fd, pid_t _pid);
     } while (_rc == -1 && errno == EINTR); \
     _rc; })
 
+extern ssize_t __pread_chk(int, void*, size_t, off_t, size_t);
+__errordecl(__pread_dest_size_error, "pread called with size bigger than destination");
+__errordecl(__pread_count_toobig_error, "pread called with count > SSIZE_MAX");
+extern ssize_t __pread_real(int, void*, size_t, off_t) __RENAME(pread);
+
+extern ssize_t __pread64_chk(int, void*, size_t, off64_t, size_t);
+__errordecl(__pread64_dest_size_error, "pread64 called with size bigger than destination");
+__errordecl(__pread64_count_toobig_error, "pread64 called with count > SSIZE_MAX");
+extern ssize_t __pread64_real(int, void*, size_t, off64_t) __RENAME(pread64);
+
 extern ssize_t __read_chk(int, void*, size_t, size_t);
 __errordecl(__read_dest_size_error, "read called with size bigger than destination");
 __errordecl(__read_count_toobig_error, "read called with count > SSIZE_MAX");
@@ -231,6 +241,62 @@ extern ssize_t __read_real(int, void*, size_t) __RENAME(read);
 
 #if defined(__BIONIC_FORTIFY)
 
+#if defined(__USE_FILE_OFFSET64)
+#define __PREAD_PREFIX(x) __pread64_ ## x
+#else
+#define __PREAD_PREFIX(x) __pread_ ## x
+#endif
+
+__BIONIC_FORTIFY_INLINE
+ssize_t pread(int fd, void* buf, size_t count, off_t offset) {
+    size_t bos = __bos0(buf);
+
+#if !defined(__clang__)
+    if (__builtin_constant_p(count) && (count > SSIZE_MAX)) {
+        __PREAD_PREFIX(count_toobig_error)();
+    }
+
+    if (bos == __BIONIC_FORTIFY_UNKNOWN_SIZE) {
+        return __PREAD_PREFIX(real)(fd, buf, count, offset);
+    }
+
+    if (__builtin_constant_p(count) && (count > bos)) {
+        __PREAD_PREFIX(dest_size_error)();
+    }
+
+    if (__builtin_constant_p(count) && (count <= bos)) {
+        return __PREAD_PREFIX(real)(fd, buf, count, offset);
+    }
+#endif
+
+    return __PREAD_PREFIX(chk)(fd, buf, count, offset, bos);
+}
+
+__BIONIC_FORTIFY_INLINE
+ssize_t pread64(int fd, void* buf, size_t count, off64_t offset) {
+    size_t bos = __bos0(buf);
+
+#if !defined(__clang__)
+    if (__builtin_constant_p(count) && (count > SSIZE_MAX)) {
+        __pread64_count_toobig_error();
+    }
+
+    if (bos == __BIONIC_FORTIFY_UNKNOWN_SIZE) {
+        return __pread64_real(fd, buf, count, offset);
+    }
+
+    if (__builtin_constant_p(count) && (count > bos)) {
+        __pread64_dest_size_error();
+    }
+
+    if (__builtin_constant_p(count) && (count <= bos)) {
+        return __pread64_real(fd, buf, count, offset);
+    }
+#endif
+
+    return __pread64_chk(fd, buf, count, offset, bos);
+}
+
 __BIONIC_FORTIFY_INLINE
 ssize_t read(int fd, void* buf, size_t count) {
     size_t bos = __bos0(buf);
@@ -255,6 +321,7 @@ ssize_t read(int fd, void* buf, size_t count) {
 
     return __read_chk(fd, buf, count, bos);
 }
+
 #endif /* defined(__BIONIC_FORTIFY) */
 
 __END_DECLS