Re: [Crash-utility] [PATCH v2] Fixed the segment fault when ikconfig passed nonstandard values
Hi Jackie,
-----Original Message-----
From: Jackie Liu <liuyun01(a)kylinos.cn>
Some strange reasons may cause kcore to collect some strange
entries of ikconfig, such as CONFIG_SECU+[some hex data] causes
the 'val' to be NULL, and then crashes when strdup.
CONFIG_SECU+[some hex data] to be **strings that don't
contain the delimitor string '='** and then strtok_r() interprets
it as consisting of a single token, hence val resulting in having NULL.
Thanks for the update, I will modify the commit message a bit more
as follows, I think you use arm64 kernels:
---
Fix for a segmentation fault when analyzing arm64 kernels that are
configured with CONFIG_IKCONFIG and have a strange entry that does
not contain the delimiter "=", such as "CONFIG_SECU+[some hex data]".
Without the patch, in the add_ikconfig_entry() function, strtok_r()
interprets it as consisting of a single token and the val variable
is set to NULL, and then strdup() crashes.
---
and
Acked-by: Kazuhito Hagio <k-hagio-ab(a)nec.com>
Please wait for another ack.
Thanks,
Kazu
[d.hatayama(a)fujitsu.com: rewrite comment]
Suggested-by: HAGIO KAZUHITO(萩尾 一仁) <k-hagio-ab(a)nec.com>
Signed-off-by: Jackie Liu <liuyun01(a)kylinos.cn>
---
kernel.c | 14 +++++++++++---
1 file changed, 11 insertions(+), 3 deletions(-)
diff --git a/kernel.c b/kernel.c
index 9871637..c8182a6 100644
--- a/kernel.c
+++ b/kernel.c
@@ -10236,7 +10236,7 @@ static struct ikconfig_list {
char *val;
} *ikconfig_all;
-static void add_ikconfig_entry(char *line, struct ikconfig_list *ent)
+static int add_ikconfig_entry(char *line, struct ikconfig_list *ent)
{
char *tokptr, *name, *val;
@@ -10244,8 +10244,16 @@ static void add_ikconfig_entry(char *line, struct ikconfig_list
*ent)
sscanf(name, "CONFIG_%s", name);
val = strtok_r(NULL, "", &tokptr);
+ if (!val) {
+ if (CRASHDEBUG(2))
+ error(WARNING, "invalid ikconfig entry: %s\n", line);
+ return FALSE;
+ }
+
ent->name = strdup(name);
ent->val = strdup(val);
+
+ return TRUE;
}
static int setup_ikconfig(char *config)
@@ -10265,8 +10273,8 @@ static int setup_ikconfig(char *config)
ent++;
if (STRNEQ(ent, "CONFIG_")) {
- add_ikconfig_entry(ent,
- &ikconfig_all[kt->ikconfig_ents++]);
+ if (add_ikconfig_entry(ent, &ikconfig_all[kt->ikconfig_ents]))
+ kt->ikconfig_ents++;
if (kt->ikconfig_ents == IKCONFIG_MAX) {
error(WARNING, "ikconfig overflow.\n");
return 1;
--
2.17.1