[PATCH resend 1/2] ws2_32: Don't read more than necessary from the inputs in select().

[Torge Matthies]

.NET Framework / old .NET Core seems to allocate not more space than
necessary for the fd_set inputs, so if the allocation fell on the edge
of the end of the heap, Wine tried to read past it.

Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=52259
Signed-off-by: Torge Matthies <openglfreak(a)googlemail.com>
---
 dlls/ws2_32/socket.c | 27 +++++++++++++++------------
 1 file changed, 15 insertions(+), 12 deletions(-)

diff --git a/dlls/ws2_32/socket.c b/dlls/ws2_32/socket.c
index 648284c10a3..446cbd0b469 100644
--- a/dlls/ws2_32/socket.c
+++ b/dlls/ws2_32/socket.c
@@ -2395,9 +2395,9 @@ int WINAPI select( int count, fd_set *read_ptr, fd_set *write_ptr,
     FD_ZERO( &read );
     FD_ZERO( &write );
     FD_ZERO( &except );
-    if (read_ptr) read = *read_ptr;
-    if (write_ptr) write = *write_ptr;
-    if (except_ptr) except = *except_ptr;
+    if (read_ptr) read.fd_count = read_ptr->fd_count;
+    if (write_ptr) write.fd_count = write_ptr->fd_count;
+    if (except_ptr) except.fd_count = except_ptr->fd_count;
 
     if (!(sync_event = get_sync_event())) return -1;
 
@@ -2408,26 +2408,29 @@ int WINAPI select( int count, fd_set *read_ptr, fd_set *write_ptr,
 
     for (i = 0; i < read.fd_count; ++i)
     {
-        params->sockets[params->count].socket = read.fd_array[i];
+        poll_socket = read_ptr->fd_array[i];
+        read.fd_array[i] = poll_socket;
+        params->sockets[params->count].socket = poll_socket;
         params->sockets[params->count].flags = AFD_POLL_READ | AFD_POLL_ACCEPT | AFD_POLL_HUP;
         ++params->count;
-        poll_socket = read.fd_array[i];
     }
 
     for (i = 0; i < write.fd_count; ++i)
     {
-        params->sockets[params->count].socket = write.fd_array[i];
+        poll_socket = write_ptr->fd_array[i];
+        write.fd_array[i] = poll_socket;
+        params->sockets[params->count].socket = poll_socket;
         params->sockets[params->count].flags = AFD_POLL_WRITE;
         ++params->count;
-        poll_socket = write.fd_array[i];
     }
 
     for (i = 0; i < except.fd_count; ++i)
     {
-        params->sockets[params->count].socket = except.fd_array[i];
+        poll_socket = except_ptr->fd_array[i];
+        except.fd_array[i] = poll_socket;
+        params->sockets[params->count].socket = poll_socket;
         params->sockets[params->count].flags = AFD_POLL_OOB | AFD_POLL_CONNECT_ERR;
         ++params->count;
-        poll_socket = except.fd_array[i];
     }
 
     if (!params->count)
@@ -2450,9 +2453,9 @@ int WINAPI select( int count, fd_set *read_ptr, fd_set *write_ptr,
     if (!status)
     {
         /* pointers may alias, so clear them all first */
-        if (read_ptr) FD_ZERO( read_ptr );
-        if (write_ptr) FD_ZERO( write_ptr );
-        if (except_ptr) FD_ZERO( except_ptr );
+        if (read_ptr) read_ptr->fd_count = 0;
+        if (write_ptr) write_ptr->fd_count = 0;
+        if (except_ptr) except_ptr->fd_count = 0;
 
         for (i = 0; i < params->count; ++i)
         {
-- 
2.34.1

[PATCH resend 2/2] ws2_32/tests: Test short fd_set with select().

[Torge Matthies]

Signed-off-by: Torge Matthies <openglfreak(a)googlemail.com>
---
 dlls/ws2_32/tests/sock.c | 20 ++++++++++++++++++--
 1 file changed, 18 insertions(+), 2 deletions(-)

diff --git a/dlls/ws2_32/tests/sock.c b/dlls/ws2_32/tests/sock.c
index 02713a7c625..cdf5a804952 100644
--- a/dlls/ws2_32/tests/sock.c
+++ b/dlls/ws2_32/tests/sock.c
@@ -3152,7 +3152,7 @@ static void test_select(void)
     static char tmp_buf[1024];
 
     SOCKET fdListen, fdRead, fdWrite;
-    fd_set readfds, writefds, exceptfds;
+    fd_set readfds, writefds, exceptfds, *alloc_readfds;
     unsigned int maxfd;
     int ret, len;
     char buffer;
@@ -3160,7 +3160,8 @@ static void test_select(void)
     struct sockaddr_in address;
     select_thread_params thread_params;
     HANDLE thread_handle;
-    DWORD ticks, id;
+    DWORD ticks, id, old_protect;
+    void *page_pair;
 
     fdRead = socket(AF_INET, SOCK_STREAM, 0);
     ok( (fdRead != INVALID_SOCKET), "socket failed unexpectedly: %d\n", WSAGetLastError() );
@@ -3326,6 +3327,21 @@ static void test_select(void)
     ok(FD_ISSET(fdWrite, &readfds), "fdWrite socket is not in the set\n");
     ok(FD_ISSET(fdRead, &readfds), "fdRead socket is not in the set\n");
 
+    page_pair = VirtualAlloc(NULL, 0x1000 * 2, MEM_RESERVE | MEM_COMMIT, PAGE_READWRITE);
+    if (!page_pair)
+        ok(0, "VirtualAlloc error %d\n", GetLastError());
+    else
+    {
+        BOOL vprot_ret = VirtualProtect((char*)page_pair + 0x1000, 0x1000, PAGE_NOACCESS, &old_protect);
+        ok(vprot_ret, "VirtualProtect error %d\n", GetLastError());
+        alloc_readfds = ((char*)page_pair + 0x1000) - offsetof(fd_set, fd_array[1]);
+        alloc_readfds->fd_count = 1;
+        alloc_readfds->fd_array[0] = fdRead;
+        ret = select(fdRead+1, alloc_readfds, NULL, NULL, &select_timeout);
+        ok(ret == 1, "select returned %d\n", ret);
+        VirtualFree(page_pair, 0, MEM_RELEASE);
+    }
+
     closesocket(fdRead);
     closesocket(fdWrite);
 
-- 
2.34.1