Commit 25dff94f authored by Dan Carpenter's avatar Dan Carpenter Committed by David S. Miller

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: default avatarDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 057cf65e
...@@ -93,7 +93,7 @@ capi_ctr_put(struct capi_ctr *ctr) ...@@ -93,7 +93,7 @@ capi_ctr_put(struct capi_ctr *ctr)
static inline struct capi_ctr *get_capi_ctr_by_nr(u16 contr) 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 NULL;
return capi_controller[contr - 1]; return capi_controller[contr - 1];
...@@ -103,7 +103,7 @@ static inline struct capi20_appl *__get_capi_appl_by_nr(u16 applid) ...@@ -103,7 +103,7 @@ static inline struct capi20_appl *__get_capi_appl_by_nr(u16 applid)
{ {
lockdep_assert_held(&capi_controller_lock); lockdep_assert_held(&capi_controller_lock);
if (applid - 1 >= CAPI_MAXAPPL) if (applid < 1 || applid - 1 >= CAPI_MAXAPPL)
return NULL; return NULL;
return capi_applications[applid - 1]; return capi_applications[applid - 1];
...@@ -111,7 +111,7 @@ static inline struct capi20_appl *__get_capi_appl_by_nr(u16 applid) ...@@ -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) 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 NULL;
return rcu_dereference(capi_applications[applid - 1]); return rcu_dereference(capi_applications[applid - 1]);
......
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