FreeBSD: Fix integer conversion for vnlru_free{,_vfsops}()

When reviewing #13875, I noticed that our FreeBSD code has an issue where it converts from `int64_t` to `int` when calling `vnlru_free{,_vfsops}()`. The result is that if the int64_t is `1 << 36`, the int will be 0, since the low bits are 0. Even when some low bits are set, a value such as `((1 << 36) + 1)` would truncate to 1, which is wrong. There is protection against this on 32-bit platforms, but on 64-bit platforms, there is no check to protect us, so we add a check. Reviewed-by: Alexander Motin <[email protected]> Reviewed-by: Ryan Moeller <[email protected]> Signed-off-by: Richard Yao <[email protected]> Closes #13882
openzfs · Sep 28, 2022 · 55816c6 · 55816c6
1 parent 8dcd6af
commit 55816c6
Showing 1 changed file with 6 additions and 0 deletions.
diff --git a/module/os/freebsd/zfs/arc_os.c b/module/os/freebsd/zfs/arc_os.c
@@ -161,6 +161,12 @@ arc_prune_task(void *arg)
 	int64_t nr_scan = (intptr_t)arg;
 
 	arc_reduce_target_size(ptob(nr_scan));
+
+#ifndef __ILP32__
+	if (nr_scan > INT_MAX)
+		nr_scan = INT_MAX;
+#endif
+
 #if __FreeBSD_version >= 1300139
 	sx_xlock(&arc_vnlru_lock);
 	vnlru_free_vfsops(nr_scan, &zfs_vfsops, arc_vnlru_marker);