From: Kees Cook <keescook@xxxxxxxxxxxx>
Subject: ipc/shm.c: use ERR_CAST() for shm_lock() error return
This uses ERR_CAST() instead of an open-coded cast, as it is casting
across structure pointers, which upsets __randomize_layout:
ipc/shm.c: In function `shm_lock':
ipc/shm.c:209:9: note: randstruct: casting between randomized structure pointer types (ssa): `struct shmid_kernel' and `struct kern_ipc_perm'
return (void *)ipcp;
^~~~~~~~~~~~
Link: http://lkml.kernel.org/r/20180919180722.GA15073@beast
Fixes: 82061c57ce93 ("ipc: drop ipc_lock()")
Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
Cc: Davidlohr Bueso <dbueso@xxxxxxx>
Cc: Manfred Spraul <manfred@xxxxxxxxxxxxxxxx>
Cc: Arnd Bergmann <arnd@xxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
ipc/shm.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/ipc/shm.c~ipc-shm-use-err_cast-for-shm_lock-error-return
+++ a/ipc/shm.c
@@ -206,7 +206,7 @@ err:
* Callers of shm_lock() must validate the status of the returned ipc
* object pointer and error out as appropriate.
*/
- return (void *)ipcp;
+ return ERR_CAST(ipcp);
}
static inline void shm_lock_by_ptr(struct shmid_kernel *ipcp)
_
