From 25dff94ff9df40d4d663bb6ea3193a7758cc50e5 Mon Sep 17 00:00:00 2001 From: Dan Carpenter Date: Sun, 19 May 2013 08:36:36 +0000 Subject: [PATCH] isdn/kcapi: fix a small underflow In get_capi_ctr_by_nr() and get_capi_appl_by_nr() the parameter comes from skb->data. The current code can underflow to one space before the start of the array. The sanity check isn't needed in __get_capi_appl_by_nr() but I changed it to match the others. Signed-off-by: Dan Carpenter Signed-off-by: David S. Miller --- drivers/isdn/capi/kcapi.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/isdn/capi/kcapi.c b/drivers/isdn/capi/kcapi.c index 9b1b274..c123709 100644 --- a/drivers/isdn/capi/kcapi.c +++ b/drivers/isdn/capi/kcapi.c @@ -93,7 +93,7 @@ capi_ctr_put(struct capi_ctr *ctr) static inline struct capi_ctr *get_capi_ctr_by_nr(u16 contr) { - if (contr - 1 >= CAPI_MAXCONTR) + if (contr < 1 || contr - 1 >= CAPI_MAXCONTR) return NULL; return capi_controller[contr - 1]; @@ -103,7 +103,7 @@ static inline struct capi20_appl *__get_capi_appl_by_nr(u16 applid) { lockdep_assert_held(&capi_controller_lock); - if (applid - 1 >= CAPI_MAXAPPL) + if (applid < 1 || applid - 1 >= CAPI_MAXAPPL) return NULL; return capi_applications[applid - 1]; @@ -111,7 +111,7 @@ static inline struct capi20_appl *__get_capi_appl_by_nr(u16 applid) static inline struct capi20_appl *get_capi_appl_by_nr(u16 applid) { - if (applid - 1 >= CAPI_MAXAPPL) + if (applid < 1 || applid - 1 >= CAPI_MAXAPPL) return NULL; return rcu_dereference(capi_applications[applid - 1]); -- 2.7.4