Messages in this thread Patch in this message |  | | | Date | Sat, 15 Mar 2008 01:10:34 +0200 | | Subject | [PATCH BUGFIX -rc5] Smack: Do not dereference NULL ipc object | | From | "Ahmed S. Darwish" <> |
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Hi all,
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: Ahmed S. Darwish <darwish.07@gmail.com> --- smack_lsm.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c index 0241fd3..38d7075 100644 --- a/security/smack/smack_lsm.c +++ b/security/smack/smack_lsm.c @@ -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); } Regards, --
"Better to light a candle, than curse the darkness"
Ahmed S. Darwish Homepage: http://darwish.07.googlepages.com Blog: http://darwish-07.blogspot.com
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