diff options
Diffstat (limited to 'ipc/shm.c')
| -rw-r--r-- | ipc/shm.c | 20 |
1 files changed, 15 insertions, 5 deletions
diff --git a/ipc/shm.c b/ipc/shm.c index 7acda23430aa..4643865e9171 100644 --- a/ipc/shm.c +++ b/ipc/shm.c @@ -909,9 +909,11 @@ static int shmctl_stat(struct ipc_namespace *ns, int shmid, int cmd, struct shmid64_ds *tbuf) { struct shmid_kernel *shp; - int result; + int id = 0; int err; + memset(tbuf, 0, sizeof(*tbuf)); + rcu_read_lock(); if (cmd == SHM_STAT) { shp = shm_obtain_object(ns, shmid); @@ -919,14 +921,13 @@ static int shmctl_stat(struct ipc_namespace *ns, int shmid, err = PTR_ERR(shp); goto out_unlock; } - result = shp->shm_perm.id; + id = shp->shm_perm.id; } else { shp = shm_obtain_object_check(ns, shmid); if (IS_ERR(shp)) { err = PTR_ERR(shp); goto out_unlock; } - result = 0; } err = -EACCES; @@ -937,7 +938,14 @@ static int shmctl_stat(struct ipc_namespace *ns, int shmid, if (err) goto out_unlock; - memset(tbuf, 0, sizeof(*tbuf)); + ipc_lock_object(&shp->shm_perm); + + if (!ipc_valid_object(&shp->shm_perm)) { + ipc_unlock_object(&shp->shm_perm); + err = -EIDRM; + goto out_unlock; + } + kernel_to_ipc64_perm(&shp->shm_perm, &tbuf->shm_perm); tbuf->shm_segsz = shp->shm_segsz; tbuf->shm_atime = shp->shm_atim; @@ -946,8 +954,10 @@ static int shmctl_stat(struct ipc_namespace *ns, int shmid, tbuf->shm_cpid = shp->shm_cprid; tbuf->shm_lpid = shp->shm_lprid; tbuf->shm_nattch = shp->shm_nattch; + + ipc_unlock_object(&shp->shm_perm); rcu_read_unlock(); - return result; + return id; out_unlock: rcu_read_unlock(); |