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&gt; > > 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&gt; 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&gt; > Signed-off-by: Jackie Liu <liuyun01(a)kylinos.cn&gt; > --- > 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 > >