linux-kernel - [PATCH] RDMA/ocrdma: fix use after free in ocrdma_dealloc_ucontext

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Date:   Tue, 29 Dec 2020 18:46:53 -0800
From:   trix@...hat.com
To:     selvin.xavier@...adcom.com, devesh.sharma@...adcom.com,
        dledford@...hat.com, jgg@...pe.ca, leon@...nel.org,
        maxg@...lanox.com, galpress@...zon.com, michaelgur@...dia.com,
        monis@...lanox.com, gustavoars@...nel.org
Cc:     linux-rdma@...r.kernel.org, linux-kernel@...r.kernel.org,
        Tom Rix <trix@...hat.com>
Subject: [PATCH] RDMA/ocrdma: fix use after free in ocrdma_dealloc_ucontext_pd()

From: Tom Rix <trix@...hat.com>

In ocrdma_dealloc_ucontext_pd() uctx->cntxt_pd is assigned to
the variable pd and then after uctx->cntxt_pd is freed, the
variable pd is passed to function _ocrdma_dealloc_pd() which
dereferences pd directly or through its call to
ocrdma_mbx_dealloc_pd().

Reorder the free using the variable pd.

Fixes: 21a428a019c9 ("RDMA: Handle PD allocations by IB/core")
Signed-off-by: Tom Rix <trix@...hat.com>
---
 drivers/infiniband/hw/ocrdma/ocrdma_verbs.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/infiniband/hw/ocrdma/ocrdma_verbs.c b/drivers/infiniband/hw/ocrdma/ocrdma_verbs.c
index bc98bd950d99..3acb5c10b155 100644
--- a/drivers/infiniband/hw/ocrdma/ocrdma_verbs.c
+++ b/drivers/infiniband/hw/ocrdma/ocrdma_verbs.c
@@ -434,9 +434,9 @@ static void ocrdma_dealloc_ucontext_pd(struct ocrdma_ucontext *uctx)
 		pr_err("%s(%d) Freeing in use pdid=0x%x.\n",
 		       __func__, dev->id, pd->id);
 	}
-	kfree(uctx->cntxt_pd);
 	uctx->cntxt_pd = NULL;
 	_ocrdma_dealloc_pd(dev, pd);
+	kfree(pd);
 }
 
 static struct ocrdma_pd *ocrdma_get_ucontext_pd(struct ocrdma_ucontext *uctx)
-- 
2.27.0