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 <[email protected]>
Acked-by: Davidlohr Bueso <[email protected]>
Acked-by: KOSAKI Motohiro <[email protected]>
Acked-by: Michael Kerrisk <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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;
