Re: [PATCH] ipc: Fail build if IPC structures change layout
On Fri, 19 May 2017 16:44:00 -0700 Kees Cookwrote: > Since struct layout can be seen at build-time, turn runtime report > into a build failure so it can be fixed more quickly. I've just dropped the patch which this fixes, due to runtime issues. Manfred, please include this in the resend?
Re: [PATCH] ipc: Fail build if IPC structures change layout
On Fri, 19 May 2017 16:44:00 -0700 Kees Cook wrote: > Since struct layout can be seen at build-time, turn runtime report > into a build failure so it can be fixed more quickly. I've just dropped the patch which this fixes, due to runtime issues. Manfred, please include this in the resend?
[PATCH] ipc: Fail build if IPC structures change layout
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 SpraulSigned-off-by: Kees Cook --- 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
[PATCH] ipc: Fail build if IPC structures change layout
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 Signed-off-by: Kees Cook --- 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