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Commit 1d252fb8 authored by Ahmed S. Darwish's avatar Ahmed S. Darwish Committed by Linus Torvalds
Browse files

smack: do not dereference NULL ipc object 



In the SYSV ipc msgctl(),semctl(),shmctl() family, if the user passed *_INFO
as the desired operation, no specific object is meant to be controlled and
only system-wide information is returned.  This leads to a NULL IPC object in
the LSM hooks if the _INFO flag is given.

Avoid dereferencing this NULL pointer in Smack ipc *ctl() methods.

Signed-off-by: default avatarAhmed S. Darwish <darwish.07@gmail.com>
Acked-by: default avatarCasey Schaufler <casey@schaufler-ca.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 4ebf8984

security/smack/smack_lsm.c

+6 −3
Original line number Diff line number Diff line
@@ -1508,7 +1508,7 @@ static int smack_shm_associate(struct shmid_kernel *shp, int shmflg) 
 */

static int smack_shm_shmctl(struct shmid_kernel *shp, int cmd)

{

	char *ssp = smack_of_shm(shp);

	char *ssp;

	int may;



	switch (cmd) {
@@ -1532,6 +1532,7 @@ static int smack_shm_shmctl(struct shmid_kernel *shp, int cmd) 
		return -EINVAL;

	}



	ssp = smack_of_shm(shp);

	return smk_curacc(ssp, may);

}
@@ -1616,7 +1617,7 @@ static int smack_sem_associate(struct sem_array *sma, int semflg) 
 */

static int smack_sem_semctl(struct sem_array *sma, int cmd)

{

	char *ssp = smack_of_sem(sma);

	char *ssp;

	int may;



	switch (cmd) {
@@ -1645,6 +1646,7 @@ static int smack_sem_semctl(struct sem_array *sma, int cmd) 
		return -EINVAL;

	}



	ssp = smack_of_sem(sma);

	return smk_curacc(ssp, may);

}
@@ -1730,7 +1732,7 @@ static int smack_msg_queue_associate(struct msg_queue *msq, int msqflg) 
 */

static int smack_msg_queue_msgctl(struct msg_queue *msq, int cmd)

{

	char *msp = smack_of_msq(msq);

	char *msp;

	int may;



	switch (cmd) {
@@ -1752,6 +1754,7 @@ static int smack_msg_queue_msgctl(struct msg_queue *msq, int cmd) 
		return -EINVAL;

	}



	msp = smack_of_msq(msq);

	return smk_curacc(msp, may);

}