mISDN: Fix null pointer dereference at mISDN_FsmNew

If mISDN_FsmNew() fails to allocate memory for jumpmatrix
then null pointer dereference will occur on any write to
jumpmatrix.

The patch adds check on successful allocation and
corresponding error handling.

Found by Linux Driver Verification project (linuxtesting.org).

Signed-off-by: Anton Vasilyev <vasilyev@ispras.ru>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Anton Vasilyev 2017-08-11 15:57:22 +03:00 committed by David S. Miller
parent bb3afda4fc
commit 54a6a043fb
5 changed files with 36 additions and 9 deletions

View File

@ -26,7 +26,7 @@
#define FSM_TIMER_DEBUG 0
void
int
mISDN_FsmNew(struct Fsm *fsm,
struct FsmNode *fnlist, int fncount)
{
@ -34,6 +34,8 @@ mISDN_FsmNew(struct Fsm *fsm,
fsm->jumpmatrix = kzalloc(sizeof(FSMFNPTR) * fsm->state_count *
fsm->event_count, GFP_KERNEL);
if (fsm->jumpmatrix == NULL)
return -ENOMEM;
for (i = 0; i < fncount; i++)
if ((fnlist[i].state >= fsm->state_count) ||
@ -45,6 +47,7 @@ mISDN_FsmNew(struct Fsm *fsm,
} else
fsm->jumpmatrix[fsm->state_count * fnlist[i].event +
fnlist[i].state] = (FSMFNPTR) fnlist[i].routine;
return 0;
}
EXPORT_SYMBOL(mISDN_FsmNew);

View File

@ -55,7 +55,7 @@ struct FsmTimer {
void *arg;
};
extern void mISDN_FsmNew(struct Fsm *, struct FsmNode *, int);
extern int mISDN_FsmNew(struct Fsm *, struct FsmNode *, int);
extern void mISDN_FsmFree(struct Fsm *);
extern int mISDN_FsmEvent(struct FsmInst *, int , void *);
extern void mISDN_FsmChangeState(struct FsmInst *, int);

View File

@ -414,8 +414,7 @@ l1_init(u_int *deb)
l1fsm_s.event_count = L1_EVENT_COUNT;
l1fsm_s.strEvent = strL1Event;
l1fsm_s.strState = strL1SState;
mISDN_FsmNew(&l1fsm_s, L1SFnList, ARRAY_SIZE(L1SFnList));
return 0;
return mISDN_FsmNew(&l1fsm_s, L1SFnList, ARRAY_SIZE(L1SFnList));
}
void

View File

@ -2247,15 +2247,26 @@ static struct Bprotocol X75SLP = {
int
Isdnl2_Init(u_int *deb)
{
int res;
debug = deb;
mISDN_register_Bprotocol(&X75SLP);
l2fsm.state_count = L2_STATE_COUNT;
l2fsm.event_count = L2_EVENT_COUNT;
l2fsm.strEvent = strL2Event;
l2fsm.strState = strL2State;
mISDN_FsmNew(&l2fsm, L2FnList, ARRAY_SIZE(L2FnList));
TEIInit(deb);
res = mISDN_FsmNew(&l2fsm, L2FnList, ARRAY_SIZE(L2FnList));
if (res)
goto error;
res = TEIInit(deb);
if (res)
goto error_fsm;
return 0;
error_fsm:
mISDN_FsmFree(&l2fsm);
error:
mISDN_unregister_Bprotocol(&X75SLP);
return res;
}
void

View File

@ -1387,23 +1387,37 @@ create_teimanager(struct mISDNdevice *dev)
int TEIInit(u_int *deb)
{
int res;
debug = deb;
teifsmu.state_count = TEI_STATE_COUNT;
teifsmu.event_count = TEI_EVENT_COUNT;
teifsmu.strEvent = strTeiEvent;
teifsmu.strState = strTeiState;
mISDN_FsmNew(&teifsmu, TeiFnListUser, ARRAY_SIZE(TeiFnListUser));
res = mISDN_FsmNew(&teifsmu, TeiFnListUser, ARRAY_SIZE(TeiFnListUser));
if (res)
goto error;
teifsmn.state_count = TEI_STATE_COUNT;
teifsmn.event_count = TEI_EVENT_COUNT;
teifsmn.strEvent = strTeiEvent;
teifsmn.strState = strTeiState;
mISDN_FsmNew(&teifsmn, TeiFnListNet, ARRAY_SIZE(TeiFnListNet));
res = mISDN_FsmNew(&teifsmn, TeiFnListNet, ARRAY_SIZE(TeiFnListNet));
if (res)
goto error_smn;
deactfsm.state_count = DEACT_STATE_COUNT;
deactfsm.event_count = DEACT_EVENT_COUNT;
deactfsm.strEvent = strDeactEvent;
deactfsm.strState = strDeactState;
mISDN_FsmNew(&deactfsm, DeactFnList, ARRAY_SIZE(DeactFnList));
res = mISDN_FsmNew(&deactfsm, DeactFnList, ARRAY_SIZE(DeactFnList));
if (res)
goto error_deact;
return 0;
error_deact:
mISDN_FsmFree(&teifsmn);
error_smn:
mISDN_FsmFree(&teifsmu);
error:
return res;
}
void TEIFree(void)