linux-kernel - [PATCH 4.4 132/312] mtd: nand: denali: add missing nand_release() call in denali

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

Message-Id: <20200508123133.790481132@linuxfoundation.org>
Date:   Fri,  8 May 2020 14:32:03 +0200
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org,
        Boris Brezillon <boris.brezillon@...e-electrons.com>,
        Dinh Nguyen <dinguyen@...nsource.altera.com>,
        Brian Norris <computersforpeace@...il.com>
Subject: [PATCH 4.4 132/312] mtd: nand: denali: add missing nand_release() call in denali_remove()

From: Boris Brezillon <boris.brezillon@...e-electrons.com>

commit 320092a05dab2f44819c42f33d6b51efb6c474f2 upstream.

Unregister the NAND device from the NAND subsystem when removing a denali
NAND controller, otherwise the MTD attached to the NAND device is still
exposed by the MTD layer, and accesses to this device will likely crash
the system.

Fixes: 2a0a288ec258 ("mtd: denali: split the generic driver and PCI layer")
Signed-off-by: Boris Brezillon <boris.brezillon@...e-electrons.com>
Acked-by: Dinh Nguyen <dinguyen@...nsource.altera.com>
Signed-off-by: Brian Norris <computersforpeace@...il.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>

---
 drivers/mtd/nand/denali.c |   11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

--- a/drivers/mtd/nand/denali.c
+++ b/drivers/mtd/nand/denali.c
@@ -1622,9 +1622,16 @@ EXPORT_SYMBOL(denali_init);
 /* driver exit point */
 void denali_remove(struct denali_nand_info *denali)
 {
+	/*
+	 * Pre-compute DMA buffer size to avoid any problems in case
+	 * nand_release() ever changes in a way that mtd->writesize and
+	 * mtd->oobsize are not reliable after this call.
+	 */
+	int bufsize = denali->mtd.writesize + denali->mtd.oobsize;
+
+	nand_release(&denali->mtd);
 	denali_irq_cleanup(denali->irq, denali);
-	dma_unmap_single(denali->dev, denali->buf.dma_buf,
-			 denali->mtd.writesize + denali->mtd.oobsize,
+	dma_unmap_single(denali->dev, denali->buf.dma_buf, bufsize,
 			 DMA_BIDIRECTIONAL);
 }
 EXPORT_SYMBOL(denali_remove);