commit b09d64064bd1ea5e5c37b2d5089e1cc3f65801b2
author Filip Bozuta <Filip.Bozuta@syrmia.com> Mon Jul 27 22:13:26 2020 +0200
committer Laurent Vivier <laurent@vivier.eu> Thu Aug 27 12:29:49 2020 +0200
tree 4a5ac55a94cdbe0ac5afe1fa455d98445ef2d861
parent 0a7ec8493d506d82aa17bf0ab84231e0a92f8975

linux-user: Fix 'clock_nanosleep()' implementation

Implementation of syscall 'clock_nanosleep()' in 'syscall.c' uses
functions 'target_to_host_timespec()' and 'host_to_target_timespec()'
to transfer the value of 'struct timespec' between target and host.
However, the implementation doesn't check whether this conversion
succeeds and thus can return an unaproppriate error instead of 'EFAULT'
that is expected. This was confirmed with the modified LTP test suite
where testcases with bad 'struct timespec' adress for 'clock_nanosleep()'
were added. This modified LTP suite can be found at:
https://github.com/bozutaf/ltp

(Patch with this new test case will be sent to LTP mailing list soon)

Signed-off-by: Filip Bozuta <Filip.Bozuta@syrmia.com>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <20200727201326.401519-1-Filip.Bozuta@syrmia.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>

linux-user/syscall.c

diff --git a/linux-user/syscall.c b/linux-user/syscall.c
index 5b3fce3..e387246 100644
--- a/linux-user/syscall.c
+++ b/linux-user/syscall.c
@@ -11875,7 +11875,9 @@
     case TARGET_NR_clock_nanosleep:
     {
         struct timespec ts;
-        target_to_host_timespec(&ts, arg3);
+        if (target_to_host_timespec(&ts, arg3)) {
+            return -TARGET_EFAULT;
+        }
         ret = get_errno(safe_clock_nanosleep(arg1, arg2,
                                              &ts, arg4 ? &ts : NULL));
         /*
@@ -11883,8 +11885,9 @@
          * with error -TARGET_EINTR and if arg4 is not NULL and arg2 is not
          * TIMER_ABSTIME, it returns the remaining unslept time in arg4.
          */
-        if (ret == -TARGET_EINTR && arg4 && arg2 != TIMER_ABSTIME) {
-            host_to_target_timespec(arg4, &ts);
+        if (ret == -TARGET_EINTR && arg4 && arg2 != TIMER_ABSTIME &&
+            host_to_target_timespec(arg4, &ts)) {
+              return -TARGET_EFAULT;
         }
 
         return ret;