[Qemu-devel] [PATCH] linux-user/syscall: let recvfrom(struct sockaddr *) use abi_ulong

["Philippe Mathieu-Daudé" <f4bug@amsat.org>]

Currently recvfrom() is restricted to handle 32-bit pointers,
remove this limit for 64-bit hosts.

This fixes:

  31572 socket(AF_NETLINK, SOCK_RAW, NETLINK_AUDIT) = 3
  ...
  31572 sendto(3, {{len=124, type=0x454 /* NLMSG_??? */, flags=NLM_F_REQUEST|NLM_F_ACK, seq=1, pid=0}, "op=test:message acct=\"?\" exe=\"/tmp/nl-bad-addr\" hostname=localhost addr=? terminal=/dev/pts/2 res=success\0\0\0"}, 124, 0, 0xfffffa3897d0, 0) = 124
  31572 ppoll([{fd=3, events=POLLIN}], 1, {tv_sec=0, tv_nsec=500000000}, NULL, 0) = 1 ([{fd=3, revents=POLLIN}], left {tv_sec=0, tv_nsec=499993180})
  31572 recvfrom(3, 0x112a50eb4, 8988, MSG_PEEK|MSG_DONTWAIT, 0xfffffa3897e0, 0x42) = -1 EFAULT (Bad address)

Reported-by: Guido Günther <agx@sigxcpu.org>
Message-id: 20180123120541.GA14216@bogon.m.sigxcpu.org
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
---
 linux-user/syscall.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/linux-user/syscall.c b/linux-user/syscall.c
index 11c9116c4a..28805b1785 100644
--- a/linux-user/syscall.c
+++ b/linux-user/syscall.c
@@ -4032,7 +4032,7 @@ static abi_long do_recvfrom(int fd, abi_ulong msg, size_t len, int flags,
     if (!host_msg)
         return -TARGET_EFAULT;
     if (target_addr) {
-        if (get_user_u32(addrlen, target_addrlen)) {
+        if (get_user_ual(addrlen, target_addrlen)) {
             ret = -TARGET_EFAULT;
             goto fail;
         }
@@ -4053,7 +4053,7 @@ static abi_long do_recvfrom(int fd, abi_ulong msg, size_t len, int flags,
         }
         if (target_addr) {
             host_to_target_sockaddr(target_addr, addr, addrlen);
-            if (put_user_u32(addrlen, target_addrlen)) {
+            if (put_user_ual(addrlen, target_addrlen)) {
                 ret = -TARGET_EFAULT;
                 goto fail;
             }
-- 
2.15.1