From 4eb7a66d9410927fb8fbafad8b8298b627cdd128 Mon Sep 17 00:00:00 2001
From: Jason Wessel <jason.wessel@windriver.com>
Date: Sun, 3 Feb 2013 09:32:28 -0600
Subject: [PATCH] kdb: Fix overlap in buffers with strcpy
Maxime reported that strcpy(s->usage, s->usage+1) has no definitive
guarantee that it will work on all archs the same way when you have
overlapping memory. The fix is simple for the kdb code because we
still have the original string memory in the function scope, so we
just have to use that as the argument instead.
Reported-by: Maxime Villard <rustyBSD@gmx.fr>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
---
kernel/debug/kdb/kdb_main.c | 30 +++++++++++++++++++++---------
1 file changed, 21 insertions(+), 9 deletions(-)
diff --git a/kernel/debug/kdb/kdb_main.c b/kernel/debug/kdb/kdb_main.c
index 437b74ddca81e..de22c8cc6c30c 100644
--- a/kernel/debug/kdb/kdb_main.c
+++ b/kernel/debug/kdb/kdb_main.c
@@ -683,32 +683,44 @@ static int kdb_defcmd(int argc, const char **argv)
return KDB_ARGCOUNT;
defcmd_set = kmalloc((defcmd_set_count + 1) * sizeof(*defcmd_set),
GFP_KDB);
- if (!defcmd_set) {
- kdb_printf("Could not allocate new defcmd_set entry for %s\n",
- argv[1]);
- defcmd_set = save_defcmd_set;
- return KDB_NOTIMP;
- }
+ if (!defcmd_set)
+ goto fail_defcmd;
memcpy(defcmd_set, save_defcmd_set,
defcmd_set_count * sizeof(*defcmd_set));
- kfree(save_defcmd_set);
s = defcmd_set + defcmd_set_count;
memset(s, 0, sizeof(*s));
s->usable = 1;
s->name = kdb_strdup(argv[1], GFP_KDB);
+ if (!s->name)
+ goto fail_name;
s->usage = kdb_strdup(argv[2], GFP_KDB);
+ if (!s->usage)
+ goto fail_usage;
s->help = kdb_strdup(argv[3], GFP_KDB);
+ if (!s->help)
+ goto fail_help;
if (s->usage[0] == '"') {
- strcpy(s->usage, s->usage+1);
+ strcpy(s->usage, argv[2]+1);
s->usage[strlen(s->usage)-1] = '\0';
}
if (s->help[0] == '"') {
- strcpy(s->help, s->help+1);
+ strcpy(s->help, argv[3]+1);
s->help[strlen(s->help)-1] = '\0';
}
++defcmd_set_count;
defcmd_in_progress = 1;
+ kfree(save_defcmd_set);
return 0;
+fail_help:
+ kfree(s->usage);
+fail_usage:
+ kfree(s->name);
+fail_name:
+ kfree(defcmd_set);
+fail_defcmd:
+ kdb_printf("Could not allocate new defcmd_set entry for %s\n", argv[1]);
+ defcmd_set = save_defcmd_set;
+ return KDB_NOTIMP;
}
/*
--
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