early_res: Need to save the allocation name in drop_range_partial()

During free_early_partial(), reserve_early_without_check() could end
extending the early_res area from __check_and_double_early_res(); as a
result, the location of the name for the current reservation could
change.

Therefore, we need to save a local copy of the name.

[ hpa: rewrote comment and checkin description ]

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
LKML-Reference: <4B8C7C94.7070000@kernel.org>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>

1 files changed, 12 insertions, 2 deletions

diff --git a/kernel/early_res.c b/kernel/early_res.c
index 9ab11cd8485..3cb2c661bb7 100644
--- a/kernel/early_res.c
+++ b/kernel/early_res.c
@@ -79,9 +79,19 @@ static void __init drop_range_partial(int i, u64 start, u64 end)
                 /* make head segment */
                 early_res[i].end = common_start;
                 if (old_end > common_end) {
+                        char name[15];
+
+                        /*
+                         * Save a local copy of the name, since the
+                         * early_res array could get resized inside
+                         * reserve_early_without_check() ->
+                         * __check_and_double_early_res(), which would
+                         * make the current name pointer invalid.
+                         */
+                        strncpy(name, early_res[i].name,
+                                         sizeof(early_res[i].name) - 1);
                         /* add another for left over on tail */
-                        reserve_early_without_check(common_end, old_end,
-                                         early_res[i].name);
+                        reserve_early_without_check(common_end, old_end, name);
                 }
                 return;
         } else {