diff mbox series

linux-user: fix emulation of accept4/getpeername/getsockname/recvfrom syscalls

Message ID mvmh8dt3vrp.fsf@suse.de
State New
Headers show
Series linux-user: fix emulation of accept4/getpeername/getsockname/recvfrom syscalls | expand

Commit Message

Andreas Schwab Jan. 28, 2019, 10:46 a.m. UTC 
System calls that return a socket address do so by putting the possibly
truncated address into the provided buffer space, but setting the addrlen
parameter to the actual size of the address.  To determine how much to
copy back to the target memory the emulation needs to remember the old
value of the addrlen parameter, so that it doesn't write past the buffer
limits.

Signed-off-by: Andreas Schwab <schwab@suse.de>
---
 linux-user/syscall.c | 38 ++++++++++++++++++++++----------------
 1 file changed, 22 insertions(+), 16 deletions(-)

Comments

no-reply@patchew.org Jan. 31, 2019, 6:07 p.m. UTC | #1 
Patchew URL: https://patchew.org/QEMU/mvmh8dt3vrp.fsf@suse.de/



Hi,

This series seems to have some coding style problems. See output below for
more information:

Subject: [Qemu-devel] [PATCH] linux-user: fix emulation of accept4/getpeername/getsockname/recvfrom syscalls
Type: series
Message-id: mvmh8dt3vrp.fsf@suse.de

=== TEST SCRIPT BEGIN ===
#!/bin/bash
git config --local diff.renamelimit 0
git config --local diff.renames True
git config --local diff.algorithm histogram
./scripts/checkpatch.pl --mailback base..
=== TEST SCRIPT END ===

Updating 3c8cf5a9c21ff8782164d1def7f44bd888713384
Switched to a new branch 'test'
ca8c625f2b linux-user: fix emulation of accept4/getpeername/getsockname/recvfrom syscalls

=== OUTPUT BEGIN ===
ERROR: braces {} are necessary for all arms of this statement
#41: FILE: linux-user/syscall.c:2877:
+        if (put_user_u32(ret_addrlen, target_addrlen_addr))
[...]

ERROR: braces {} are necessary for all arms of this statement
#65: FILE: linux-user/syscall.c:2907:
+        if (put_user_u32(ret_addrlen, target_addrlen_addr))
[...]

ERROR: braces {} are necessary for all arms of this statement
#89: FILE: linux-user/syscall.c:2937:
+        if (put_user_u32(ret_addrlen, target_addrlen_addr))
[...]

total: 3 errors, 0 warnings, 98 lines checked

Commit ca8c625f2b00 (linux-user: fix emulation of accept4/getpeername/getsockname/recvfrom syscalls) has style problems, please review.  If any of these errors
are false positives report them to the maintainer, see
CHECKPATCH in MAINTAINERS.
=== OUTPUT END ===

Test command exited with code: 1


The full log is available at
http://patchew.org/logs/mvmh8dt3vrp.fsf@suse.de/testing.checkpatch/?type=message.
---
Email generated automatically by Patchew [http://patchew.org/].
Please send your feedback to patchew-devel@redhat.com
diff mbox series

Patch

diff --git a/linux-user/syscall.c b/linux-user/syscall.c
index d5db01122aa4..46ca889556c8 100644
--- a/linux-user/syscall.c
+++ b/linux-user/syscall.c
@@ -2884,7 +2884,7 @@  static abi_long do_sendrecvmmsg(int fd, abi_ulong target_msgvec,
 static abi_long do_accept4(int fd, abi_ulong target_addr,
                            abi_ulong target_addrlen_addr, int flags)
 {
-    socklen_t addrlen;
+    socklen_t addrlen, ret_addrlen;
     void *addr;
     abi_long ret;
     int host_flags;
@@ -2908,10 +2908,11 @@  static abi_long do_accept4(int fd, abi_ulong target_addr,
 
     addr = alloca(addrlen);
 
-    ret = get_errno(safe_accept4(fd, addr, &addrlen, host_flags));
+    ret_addrlen = addrlen;
+    ret = get_errno(safe_accept4(fd, addr, &ret_addrlen, host_flags));
     if (!is_error(ret)) {
-        host_to_target_sockaddr(target_addr, addr, addrlen);
-        if (put_user_u32(addrlen, target_addrlen_addr))
+        host_to_target_sockaddr(target_addr, addr, MIN(addrlen, ret_addrlen));
+        if (put_user_u32(ret_addrlen, target_addrlen_addr))
             ret = -TARGET_EFAULT;
     }
     return ret;
@@ -2921,7 +2922,7 @@  static abi_long do_accept4(int fd, abi_ulong target_addr,
 static abi_long do_getpeername(int fd, abi_ulong target_addr,
                                abi_ulong target_addrlen_addr)
 {
-    socklen_t addrlen;
+    socklen_t addrlen, ret_addrlen;
     void *addr;
     abi_long ret;
 
@@ -2937,10 +2938,11 @@  static abi_long do_getpeername(int fd, abi_ulong target_addr,
 
     addr = alloca(addrlen);
 
-    ret = get_errno(getpeername(fd, addr, &addrlen));
+    ret_addrlen = addrlen;
+    ret = get_errno(getpeername(fd, addr, &ret_addrlen));
     if (!is_error(ret)) {
-        host_to_target_sockaddr(target_addr, addr, addrlen);
-        if (put_user_u32(addrlen, target_addrlen_addr))
+        host_to_target_sockaddr(target_addr, addr, MIN(addrlen, ret_addrlen));
+        if (put_user_u32(ret_addrlen, target_addrlen_addr))
             ret = -TARGET_EFAULT;
     }
     return ret;
@@ -2950,7 +2952,7 @@  static abi_long do_getpeername(int fd, abi_ulong target_addr,
 static abi_long do_getsockname(int fd, abi_ulong target_addr,
                                abi_ulong target_addrlen_addr)
 {
-    socklen_t addrlen;
+    socklen_t addrlen, ret_addrlen;
     void *addr;
     abi_long ret;
 
@@ -2966,10 +2968,11 @@  static abi_long do_getsockname(int fd, abi_ulong target_addr,
 
     addr = alloca(addrlen);
 
-    ret = get_errno(getsockname(fd, addr, &addrlen));
+    ret_addrlen = addrlen;
+    ret = get_errno(getsockname(fd, addr, &ret_addrlen));
     if (!is_error(ret)) {
-        host_to_target_sockaddr(target_addr, addr, addrlen);
-        if (put_user_u32(addrlen, target_addrlen_addr))
+        host_to_target_sockaddr(target_addr, addr, MIN(addrlen, ret_addrlen));
+        if (put_user_u32(ret_addrlen, target_addrlen_addr))
             ret = -TARGET_EFAULT;
     }
     return ret;
@@ -3042,7 +3045,7 @@  static abi_long do_recvfrom(int fd, abi_ulong msg, size_t len, int flags,
                             abi_ulong target_addr,
                             abi_ulong target_addrlen)
 {
-    socklen_t addrlen;
+    socklen_t addrlen, ret_addrlen;
     void *addr;
     void *host_msg;
     abi_long ret;
@@ -3060,10 +3063,12 @@  static abi_long do_recvfrom(int fd, abi_ulong msg, size_t len, int flags,
             goto fail;
         }
         addr = alloca(addrlen);
+        ret_addrlen = addrlen;
         ret = get_errno(safe_recvfrom(fd, host_msg, len, flags,
-                                      addr, &addrlen));
+                                      addr, &ret_addrlen));
     } else {
         addr = NULL; /* To keep compiler quiet.  */
+        addrlen = 0; /* To keep compiler quiet.  */
         ret = get_errno(safe_recvfrom(fd, host_msg, len, flags, NULL, 0));
     }
     if (!is_error(ret)) {
@@ -3076,8 +3081,9 @@  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)) {
+            host_to_target_sockaddr(target_addr, addr,
+                                    MIN(addrlen, ret_addrlen));
+            if (put_user_u32(ret_addrlen, target_addrlen)) {
                 ret = -TARGET_EFAULT;
                 goto fail;
             }