[glibc] hurd: add validations in msync

https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=156141a8f341c92d3fde8db336dfd8cfd0cd4950

commit 156141a8f341c92d3fde8db336dfd8cfd0cd4950
Author: Etienne Brateau <[email protected]>
Date:   Mon May 25 23:11:42 2026 +0200

    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 <[email protected]>
    Message-ID: <[email protected]>

Diff:
---
 sysdeps/mach/hurd/msync.c | 23 +++++++++++++++++++----
 1 file changed, 19 insertions(+), 4 deletions(-)

diff --git a/sysdeps/mach/hurd/msync.c b/sysdeps/mach/hurd/msync.c
index 46eabd1ee7..e6c135cbf4 100644
--- 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;
 }