From: Shaobo He <shaobo@cs.utah.edu>
To: linux-rdma@vger.kernel.org
Cc: shaobo@cs.utah.edu, Steve Wise <swise@chelsio.com>,
Doug Ledford <dledford@redhat.com>,
Jason Gunthorpe <jgg@ziepe.ca>,
linux-kernel@vger.kernel.org (open list)
Subject: [PATCH] cxgb4: fix undefined behavior in mem.c
Date: Thu, 28 Feb 2019 15:38:38 -0700 [thread overview]
Message-ID: <1551393519-96595-1-git-send-email-shaobo@cs.utah.edu> (raw)
In function `c4iw_dealloc_mw`, variable mhp's value is printed after
freed, which triggers undefined behavior according to this post:
https://trust-in-soft.com/dangling-pointer-indeterminate/.
This commit fixes it by swapping the order of `kfree` and `pr_debug`.
Signed-off-by: Shaobo He <shaobo@cs.utah.edu>
---
drivers/infiniband/hw/cxgb4/mem.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/infiniband/hw/cxgb4/mem.c b/drivers/infiniband/hw/cxgb4/mem.c
index 7b76e6f..bb8e0bc 100644
--- a/drivers/infiniband/hw/cxgb4/mem.c
+++ b/drivers/infiniband/hw/cxgb4/mem.c
@@ -684,8 +684,8 @@ int c4iw_dealloc_mw(struct ib_mw *mw)
mhp->wr_waitp);
kfree_skb(mhp->dereg_skb);
c4iw_put_wr_wait(mhp->wr_waitp);
- kfree(mhp);
pr_debug("ib_mw %p mmid 0x%x ptr %p\n", mw, mmid, mhp);
+ kfree(mhp);
return 0;
}
--
2.7.4
next reply other threads:[~2019-02-28 22:38 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-02-28 22:38 Shaobo He [this message]
2019-02-28 22:56 ` [PATCH] cxgb4: fix undefined behavior in mem.c Bart Van Assche
2019-02-28 23:18 ` Shaobo He
2019-02-28 23:33 ` Bart Van Assche
2019-02-28 23:57 ` Shaobo He
2019-03-01 14:26 ` Doug Ledford
2019-03-01 21:21 ` Shaobo He
2019-03-01 18:15 ` Christopher Lameter
2019-03-04 19:54 ` Jason Gunthorpe
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