shm_tot counts the total number of pages used by shm segments.
If SHMALL is ULONG_MAX (or nearly ULONG_MAX), then the number
can overflow. Subsequent calls to shmctl(,SHM_INFO,) would return
wrong values for shm_tot.
The patch adds a detection for overflows.
Signed-off-by: Manfred Spraul <manf...@colorfullife.com>
---
ipc/shm.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/ipc/shm.c b/ipc/shm.c
index 382e2fb..2dfa3d6 100644
--- a/ipc/shm.c
+++ b/ipc/shm.c
@@ -493,7 +493,8 @@ static int newseg(struct ipc_namespace *ns, struct
ipc_params *params)
if (size < SHMMIN || size > ns->shm_ctlmax)
return -EINVAL;
- if (ns->shm_tot + numpages > ns->shm_ctlall)
+ if (ns->shm_tot + numpages < ns->shm_tot ||
+ ns->shm_tot + numpages > ns->shm_ctlall)
return -ENOSPC;
shp = ipc_rcu_alloc(sizeof(*shp));
--
1.9.0
--
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