ipc/shm.c: check for integer overflow during shmget.
SHMMAX is the upper limit for the size of a shared memory segment, counted
in bytes. The actual allocation is that size, rounded up to the next full
page.
Add a check that prevents the creation of segments where the rounded up
size causes an integer overflow.
Signed-off-by: Manfred Spraul <manfred@colorfullife.com>
Acked-by: Davidlohr Bueso <davidlohr@hp.com>
Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Acked-by: Michael Kerrisk <mtk.manpages@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/ipc/shm.c b/ipc/shm.c
index 9e51bf2..89fc354 100644
--- a/ipc/shm.c
+++ b/ipc/shm.c
@@ -493,6 +493,9 @@
if (size < SHMMIN || size > ns->shm_ctlmax)
return -EINVAL;
+ if (numpages << PAGE_SHIFT < size)
+ return -ENOSPC;
+
if (ns->shm_tot + numpages < ns->shm_tot ||
ns->shm_tot + numpages > ns->shm_ctlall)
return -ENOSPC;