lineedit: fix SEGV in isk, hexedit, ed, closes 11661

fdisk, hexedit and ed calls read_line_edit in libbb/lineedit.c with NULL
as first argument. On line 2373 of lineedit.c of busybox version 1.29.3,
state->hist_file is referenced without checking the state->flag.

This causes segmentation fault on fdisk, hexedit and ed on ARM Cortex-A9.
It somehow works on x86_64.

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 5 insertions, 4 deletions

diff --git a/libbb/lineedit.c b/libbb/lineedit.c
index 0a888fa70..1d5fef5ee 100644
--- a/libbb/lineedit.c
+++ b/libbb/lineedit.c
@@ -2383,13 +2383,14 @@ int FAST_FUNC read_line_input(line_input_t *st, const char *prompt, char *comman
                 timeout = st->timeout;
         }
 #if MAX_HISTORY > 0
+        if (state->flags & DO_HISTORY) {
 # if ENABLE_FEATURE_EDITING_SAVEHISTORY
-        if (state->hist_file)
-                if (state->cnt_history == 0)
-                        load_history(state);
+                if (state->hist_file)
+                        if (state->cnt_history == 0)
+                                load_history(state);
 # endif
-        if (state->flags & DO_HISTORY)
                 state->cur_history = state->cnt_history;
+        }
 #endif
 
         /* prepare before init handlers */