| Message ID | 1455667300-21365-1-git-send-email-colin.king@canonical.com |
|---|---|
| State | Accepted |
| Headers | show |
On 2016-02-17 08:01 AM, Colin King wrote: > From: Colin Ian King <colin.king@canonical.com> > > scan-build detected that an empty klog_old list would lead to l_old_last > being null and hence we get a null pointer dereference when assigning > old to the data in the null list. Check for a empty list and ensure > l_new is initialized to NULL for this corner case. > > Signed-off-by: Colin Ian King <colin.king@canonical.com> > --- > src/lib/src/fwts_klog.c | 21 ++++++++++++--------- > 1 file changed, 12 insertions(+), 9 deletions(-) > > diff --git a/src/lib/src/fwts_klog.c b/src/lib/src/fwts_klog.c > index 48a0e45..b5f0965 100644 > --- a/src/lib/src/fwts_klog.c > +++ b/src/lib/src/fwts_klog.c > @@ -51,7 +51,7 @@ void fwts_klog_free(fwts_list *klog) > */ > fwts_list *fwts_klog_find_changes(fwts_list *klog_old, fwts_list *klog_new) > { > - fwts_list_link *l_old, *l_new; > + fwts_list_link *l_old, *l_new = NULL; > fwts_list *klog_diff; > > if (klog_new == NULL) { > @@ -74,14 +74,17 @@ fwts_list *fwts_klog_find_changes(fwts_list *klog_old, fwts_list *klog_new) > fwts_list_foreach(l_old, klog_old) > l_old_last = l_old; > > - /* And now look for that last line in the new log */ > - old = fwts_list_data(char *, l_old_last); > - fwts_list_foreach(l_new, klog_new) { > - char *new = fwts_list_data(char *, l_new); > - if (!strcmp(new, old)) { > - /* Found last line that matches, bump to next */ > - l_new = l_new->next; > - break; > + if (l_old_last) { > + /* And now look for that last line in the new log */ > + old = fwts_list_data(char *, l_old_last); > + fwts_list_foreach(l_new, klog_new) { > + const char *new = fwts_list_data(char *, l_new); > + > + if (!strcmp(new, old)) { > + /* Found last line that matches, bump to next */ > + l_new = l_new->next; > + break; > + } > } > } > } > Acked-by: Alex Hung <alex.hung@canonical.com>
On 2016年02月17日 08:01, Colin King wrote: > From: Colin Ian King <colin.king@canonical.com> > > scan-build detected that an empty klog_old list would lead to l_old_last > being null and hence we get a null pointer dereference when assigning > old to the data in the null list. Check for a empty list and ensure > l_new is initialized to NULL for this corner case. > > Signed-off-by: Colin Ian King <colin.king@canonical.com> > --- > src/lib/src/fwts_klog.c | 21 ++++++++++++--------- > 1 file changed, 12 insertions(+), 9 deletions(-) > > diff --git a/src/lib/src/fwts_klog.c b/src/lib/src/fwts_klog.c > index 48a0e45..b5f0965 100644 > --- a/src/lib/src/fwts_klog.c > +++ b/src/lib/src/fwts_klog.c > @@ -51,7 +51,7 @@ void fwts_klog_free(fwts_list *klog) > */ > fwts_list *fwts_klog_find_changes(fwts_list *klog_old, fwts_list *klog_new) > { > - fwts_list_link *l_old, *l_new; > + fwts_list_link *l_old, *l_new = NULL; > fwts_list *klog_diff; > > if (klog_new == NULL) { > @@ -74,14 +74,17 @@ fwts_list *fwts_klog_find_changes(fwts_list *klog_old, fwts_list *klog_new) > fwts_list_foreach(l_old, klog_old) > l_old_last = l_old; > > - /* And now look for that last line in the new log */ > - old = fwts_list_data(char *, l_old_last); > - fwts_list_foreach(l_new, klog_new) { > - char *new = fwts_list_data(char *, l_new); > - if (!strcmp(new, old)) { > - /* Found last line that matches, bump to next */ > - l_new = l_new->next; > - break; > + if (l_old_last) { > + /* And now look for that last line in the new log */ > + old = fwts_list_data(char *, l_old_last); > + fwts_list_foreach(l_new, klog_new) { > + const char *new = fwts_list_data(char *, l_new); > + > + if (!strcmp(new, old)) { > + /* Found last line that matches, bump to next */ > + l_new = l_new->next; > + break; > + } > } > } > } > Acked-by: Ivan Hu <ivan.hu@canonical.com>
diff --git a/src/lib/src/fwts_klog.c b/src/lib/src/fwts_klog.c index 48a0e45..b5f0965 100644 --- a/src/lib/src/fwts_klog.c +++ b/src/lib/src/fwts_klog.c @@ -51,7 +51,7 @@ void fwts_klog_free(fwts_list *klog) */ fwts_list *fwts_klog_find_changes(fwts_list *klog_old, fwts_list *klog_new) { - fwts_list_link *l_old, *l_new; + fwts_list_link *l_old, *l_new = NULL; fwts_list *klog_diff; if (klog_new == NULL) { @@ -74,14 +74,17 @@ fwts_list *fwts_klog_find_changes(fwts_list *klog_old, fwts_list *klog_new) fwts_list_foreach(l_old, klog_old) l_old_last = l_old; - /* And now look for that last line in the new log */ - old = fwts_list_data(char *, l_old_last); - fwts_list_foreach(l_new, klog_new) { - char *new = fwts_list_data(char *, l_new); - if (!strcmp(new, old)) { - /* Found last line that matches, bump to next */ - l_new = l_new->next; - break; + if (l_old_last) { + /* And now look for that last line in the new log */ + old = fwts_list_data(char *, l_old_last); + fwts_list_foreach(l_new, klog_new) { + const char *new = fwts_list_data(char *, l_new); + + if (!strcmp(new, old)) { + /* Found last line that matches, bump to next */ + l_new = l_new->next; + break; + } } } }