hurd: add validations in msync

POSIX specs specify that invalid flags shall return EINVAL and that
ENOMEM shall be returned in case of address outside of address space or
when one or more pages are not mapped.

Signed-off-by: Etienne Brateau <etienne.brateau@gmail.com>
Message-ID: <20260525211142.131508-1-etienne.brateau@gmail.com>

diff --git a/sysdeps/mach/hurd/msync.c b/sysdeps/mach/hurd/msync.c
index 46eabd1ee7d218485df0bae274ab95a453c72b67..e6c135cbf4aec089a4c004f13afd9037b4d339c2 100644 (file)
--- a/sysdeps/mach/hurd/msync.c
+++ b/sysdeps/mach/hurd/msync.c
@@ -36,6 +36,15 @@ msync (void *addr, size_t length, int flags)
   vm_address_t cur = (vm_address_t) addr;
   vm_address_t target = cur + length;
 
+  if (flags & ~(MS_ASYNC | MS_INVALIDATE | MS_SYNC))
+    return __hurd_fail (EINVAL);
+
+  if (flags & MS_ASYNC && flags & MS_SYNC)
+    return __hurd_fail (EINVAL);
+
+  if (target < cur)
+    return __hurd_fail (ENOMEM);
+
   vm_size_t len;
   vm_prot_t prot;
   vm_prot_t max_prot;
@@ -45,6 +54,7 @@ msync (void *addr, size_t length, int flags)
   vm_offset_t offset;
 
   kern_return_t err;
+  kern_return_t unmapped_error = KERN_SUCCESS;
   int cancel_oldtype;
 
   while (cur < target)
@@ -59,13 +69,16 @@ msync (void *addr, size_t length, int flags)
        return __hurd_fail (err);
 
       if (begin > cur)
-       /* We were given an address before the first region,
-          or we found a hole.  */
-       cur = begin;
+       {
+         /* We were given an address before the first region,
+            or we found a hole.  */
+         cur = begin;
+         unmapped_error = ENOMEM;
+       }
 
       if (cur >= target)
        /* We were given an ending address within a hole. */
-       break;
+       return __hurd_fail (ENOMEM);
 
       if (MACH_PORT_VALID (obj))
        {
@@ -90,5 +103,7 @@ msync (void *addr, size_t length, int flags)
       cur = begin + len;
     }
 
+  if (unmapped_error != KERN_SUCCESS)
+    return __hurd_fail (unmapped_error);
   return 0;
 }