[PATCH] ipc/sem: ensure we left shift a ULL rather than a 32 bit integer

From	Colin King <colin.king@canonical.com>
Newsgroups	linux.kernel
Subject	[PATCH] ipc/sem: ensure we left shift a ULL rather than a 32 bit integer
Date	2016-10-28 20:20 +0200
Message-ID	<sxjUZ-3o4-7@gated-at.bofh.it> (permalink)
Organization	linux.* mail to news gateway

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From: Colin Ian King <colin.king@canonical.com>

The left shift amount is sop->sem_num % 64, which is up to 63, so
ensure we are shifting a ULL rather than a 32 bit value.

CoverityScan CID#1372862 "Bad bit shift operation"

Fixes: 7c24530cb4e3c0ae ("ipc/sem: optimize perform_atomic_semop()")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
---
 ipc/sem.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/ipc/sem.c b/ipc/sem.c
index ebd18a7..ca4aa23 100644
--- a/ipc/sem.c
+++ b/ipc/sem.c
@@ -1839,7 +1839,7 @@ SYSCALL_DEFINE4(semtimedop, int, semid, struct sembuf __user *, tsops,
 
 	max = 0;
 	for (sop = sops; sop < sops + nsops; sop++) {
-		unsigned long mask = 1 << ((sop->sem_num) % BITS_PER_LONG);
+		unsigned long mask = 1ULL << ((sop->sem_num) % BITS_PER_LONG);
 
 		if (sop->sem_num >= max)
 			max = sop->sem_num;
-- 
2.9.3

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[PATCH] ipc/sem: ensure we left shift a ULL rather than a 32 bit integer Colin King <colin.king@canonical.com> - 2016-10-28 20:20 +0200
  Re: [PATCH] ipc/sem: ensure we left shift a ULL rather than a 32 bit  integer Colin Ian King <colin.king@canonical.com> - 2016-10-28 21:30 +0200
    Re: [PATCH] ipc/sem: ensure we left shift a ULL rather than a 32 bit  integer Manfred Spraul <manfred@colorfullife.com> - 2016-10-30 16:40 +0100
  Re: [PATCH] ipc/sem: ensure we left shift a ULL rather than a 32 bit  integer Manfred Spraul <manfred@colorfullife.com> - 2016-10-28 21:30 +0200
  Re: [PATCH] ipc/sem: ensure we left shift a ULL rather than a 32 bit  integer Davidlohr Bueso <dave@stgolabs.net> - 2016-10-29 00:20 +0200

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