Messages in this thread Patch in this message | | | Date | Fri, 19 May 2017 16:44:00 -0700 | From | Kees Cook <> | Subject | [PATCH] ipc: Fail build if IPC structures change layout |
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Since struct layout can be seen at build-time, turn runtime report into a build failure so it can be fixed more quickly.
Cc: Manfred Spraul <manfred@colorfullife.com> Signed-off-by: Kees Cook <keescook@chromium.org> --- Should be applied on top of the -mm tree's IPC changes --- ipc/msg.c | 5 +---- ipc/sem.c | 5 +---- ipc/shm.c | 5 +---- 3 files changed, 3 insertions(+), 12 deletions(-)
diff --git a/ipc/msg.c b/ipc/msg.c index e9785c4d2e0d..0ed7dae7d4e8 100644 --- a/ipc/msg.c +++ b/ipc/msg.c @@ -118,10 +118,7 @@ static int newque(struct ipc_namespace *ns, struct ipc_params *params) key_t key = params->key; int msgflg = params->flg; - if (offsetof(struct msg_queue, q_perm) != 0) { - pr_err("Invalid struct sem_perm, failing msgget().\n"); - return -ENOMEM; - } + BUILD_BUG_ON(offsetof(struct msg_queue, q_perm) != 0); msq = container_of(ipc_rcu_alloc(sizeof(*msq)), struct msg_queue, q_perm); diff --git a/ipc/sem.c b/ipc/sem.c index 18241c16d07c..2109fad750b5 100644 --- a/ipc/sem.c +++ b/ipc/sem.c @@ -469,10 +469,7 @@ static int newary(struct ipc_namespace *ns, struct ipc_params *params) if (ns->used_sems + nsems > ns->sc_semmns) return -ENOSPC; - if (offsetof(struct sem_array, sem_perm) != 0) { - pr_err("Invalid struct sem_perm, failing semget().\n"); - return -ENOMEM; - } + BUILD_BUG_ON(offsetof(struct sem_array, sem_perm) != 0); size = sizeof(*sma) + nsems * sizeof(sma->sems[0]); sma = container_of(ipc_rcu_alloc(size), struct sem_array, sem_perm); diff --git a/ipc/shm.c b/ipc/shm.c index cec6df186050..2eb85bd5b855 100644 --- a/ipc/shm.c +++ b/ipc/shm.c @@ -543,10 +543,7 @@ static int newseg(struct ipc_namespace *ns, struct ipc_params *params) ns->shm_tot + numpages > ns->shm_ctlall) return -ENOSPC; - if (offsetof(struct shmid_kernel, shm_perm) != 0) { - pr_err("Invalid struct sem_perm, failing msgget().\n"); - return -ENOMEM; - } + BUILD_BUG_ON(offsetof(struct shmid_kernel, shm_perm) != 0); shp = container_of(ipc_rcu_alloc(sizeof(*shp)), struct shmid_kernel, shm_perm); -- 2.7.4
-- Kees Cook Pixel Security
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