zmo->name needs to be NonPaged

Due to IRP_MN_MOUNT_VOLUME being called at high irql, and we copy name over to VolumeLabel. Signed-off-by: Jorgen Lundman <[email protected]>
openzfsonwindows · Sep 4, 2024 · 5e7e013 · 5e7e013
1 parent 8c07c15
commit 5e7e013
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Showing 3 changed files with 41 additions and 1 deletion.
diff --git a/include/os/windows/zfs/sys/zfs_windows.h b/include/os/windows/zfs/sys/zfs_windows.h
@@ -155,6 +155,7 @@ extern int zfs_init_cache(FILE_OBJECT *fo, struct vnode *vp,
 
 /* zfs_vnop_windows_lib.h */
 extern int	AsciiStringToUnicodeString(char *in, PUNICODE_STRING out);
+extern int	AsciiStringToUnicodeStringNP(char *in, PUNICODE_STRING out);
 extern void	FreeUnicodeString(PUNICODE_STRING s);
 extern int	zfs_vfs_uuid_gen(const char *osname, uuid_t uuid);
 extern int	zfs_vfs_uuid_unparse(uuid_t uuid, char *dst);

diff --git a/module/os/windows/zfs/zfs_vnops_windows_lib.c b/module/os/windows/zfs/zfs_vnops_windows_lib.c
@@ -515,6 +515,45 @@ AsciiStringToUnicodeString(char *in, PUNICODE_STRING out)
 	return (RtlAnsiStringToUnicodeString(out, &conv, TRUE));
 }
 
+/*
+ * Same again, but use NonPaged memory.
+ * IRP_MN_MOUNT_VOLUME is called with irql==2, and
+ * we try to copy zmo->name.Buffer to VolumeLabel, which
+ * is not allowed.
+ */
+int
+AsciiStringToUnicodeStringNP(char *in, PUNICODE_STRING out)
+{
+	NTSTATUS status;
+	ULONG len;
+
+	memset(out, 0, sizeof (UNICODE_STRING));
+	if (in == NULL)
+		return (0);
+
+	status = RtlUTF8ToUnicodeN(NULL, 0, &len,
+	    in, strlen(in));
+	if (!NT_SUCCESS(status))
+		return (0);
+
+	out->Buffer = (PWSTR)ExAllocatePoolWithTag(NonPagedPoolNx,
+	    len + sizeof (WCHAR), 'tag1');
+
+	if (out->Buffer == NULL)
+		return (0);
+
+	out->Length = len;
+	out->MaximumLength = len + sizeof (WCHAR);
+
+	status = RtlUTF8ToUnicodeN(out->Buffer, out->MaximumLength,
+	    NULL,
+	    in, strlen(in));
+
+	out->Buffer[out->Length / sizeof (WCHAR)] =
+	    UNICODE_NULL;
+	return (0);
+}
+
 void
 FreeUnicodeString(PUNICODE_STRING s)
 {

diff --git a/module/os/windows/zfs/zfs_vnops_windows_mount.c b/module/os/windows/zfs/zfs_vnops_windows_mount.c
@@ -928,7 +928,7 @@ zfs_windows_mount(zfs_cmd_t *zc)
 	// Should we keep the name with slashes like "BOOM/lower" or
 	// just "lower". Turns out the name in Explorer only
 	// works for 4 chars or lower. Why?
-	AsciiStringToUnicodeString(zc->zc_name, &zmo_dcb->name);
+	AsciiStringToUnicodeStringNP(zc->zc_name, &zmo_dcb->name);
 	RtlDuplicateUnicodeString(0, &diskDeviceName, &zmo_dcb->device_name);
 
 	// strlcpy(zc->zc_value, buf, sizeof (zc->zc_value));