From: Florian Krohm <florian@eich-krohm.de>
Date: Sat, 25 Apr 2015 18:14:17 +0000 (+0000)
Subject: Fix the writev / readv wrappers. Do not read the array pointed to
X-Git-Tag: svn/VALGRIND_3_11_0~456
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=e0927ca1ea7223b1d6db155b4ed8821e05e38d59;p=thirdparty%2Fvalgrind.git

Fix the writev / readv wrappers. Do not read the array pointed to
by the 2nd argument, if the element count is negative.


git-svn-id: svn://svn.valgrind.org/valgrind/trunk@15143
---

diff --git a/coregrind/m_syswrap/syswrap-generic.c b/coregrind/m_syswrap/syswrap-generic.c
index cb3cfb1aac..2fd37d1cbe 100644
--- a/coregrind/m_syswrap/syswrap-generic.c
+++ b/coregrind/m_syswrap/syswrap-generic.c
@@ -4006,7 +4006,8 @@ PRE(sys_readv)
    if (!ML_(fd_allowed)(ARG1, "readv", tid, False)) {
       SET_STATUS_Failure( VKI_EBADF );
    } else {
-      PRE_MEM_READ( "readv(vector)", ARG2, ARG3 * sizeof(struct vki_iovec) );
+      if ((Int)ARG3 >= 0)
+         PRE_MEM_READ( "readv(vector)", ARG2, ARG3 * sizeof(struct vki_iovec) );
 
       if (ARG2 != 0) {
          /* ToDo: don't do any of the following if the vector is invalid */
@@ -4335,8 +4336,9 @@ PRE(sys_writev)
    if (!ML_(fd_allowed)(ARG1, "writev", tid, False)) {
       SET_STATUS_Failure( VKI_EBADF );
    } else {
-      PRE_MEM_READ( "writev(vector)", 
-		     ARG2, ARG3 * sizeof(struct vki_iovec) );
+      if ((Int)ARG3 >= 0)
+         PRE_MEM_READ( "writev(vector)", 
+                       ARG2, ARG3 * sizeof(struct vki_iovec) );
       if (ARG2 != 0) {
          /* ToDo: don't do any of the following if the vector is invalid */
          vec = (struct vki_iovec *)ARG2;
diff --git a/memcheck/tests/writev1.c b/memcheck/tests/writev1.c
index 82ad47f9ba..6a8c281c89 100644
--- a/memcheck/tests/writev1.c
+++ b/memcheck/tests/writev1.c
@@ -80,7 +80,7 @@ int main(void)
                 	fprintf(stderr, "expected errno = EINVAL, got %d\n", errno);
  	}
 	else 
-        	fprintf(stderr, "Error writev returned a positive value\n");
+        	fprintf(stderr, "Error readv returned a positive value\n");
 
         unlink(f_name);
         
diff --git a/memcheck/tests/writev1.stderr.exp b/memcheck/tests/writev1.stderr.exp
index 6063a3805f..0fe62eecb7 100644
--- a/memcheck/tests/writev1.stderr.exp
+++ b/memcheck/tests/writev1.stderr.exp
@@ -5,15 +5,5 @@ Syscall param writev(vector[...]) points to unaddressable byte(s)
  Address 0x........ is not stack'd, malloc'd or (recently) free'd
 
 Received EFAULT as expected
-Syscall param writev(vector) points to unaddressable byte(s)
-   ...
-   by 0x........: main (writev1.c:68)
- Address 0x........ is not stack'd, malloc'd or (recently) free'd
-
 Received EINVAL as expected
-Syscall param readv(vector) points to unaddressable byte(s)
-   ...
-   by 0x........: main (writev1.c:76)
- Address 0x........ is not stack'd, malloc'd or (recently) free'd
-
 Received EINVAL as expected