Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758734Ab2FUISw (ORCPT ); Thu, 21 Jun 2012 04:18:52 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:60951 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758714Ab2FUISs (ORCPT ); Thu, 21 Jun 2012 04:18:48 -0400 From: Keng-Yu Lin To: stable@vger.kernel.org, Greg Kroah-Hartman , wwang , Hitoshi NAKAMORI , devel@driverdev.osuosl.org, linux-kernel@vger.kernel.org Cc: Keng-Yu Lin Subject: [PATCH 3.2.y 3.3.y] staging:rts_pstor:Fix possible panic by NULL pointer dereference Date: Thu, 21 Jun 2012 16:18:39 +0800 Message-Id: <1340266719-31983-1-git-send-email-kengyu@canonical.com> X-Mailer: git-send-email 1.7.9.5 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2525 Lines: 73 From: wwang commit 0d05568ac79bfc595f1eadc3e0fd7a20a45f7b69 upstream. rtsx_transport.c (rtsx_transfer_sglist_adma_partial): pointer struct scatterlist *sg, which is mapped in dma_map_sg, is used as an iterator in later transfer operation. It is corrupted and passed to dma_unmap_sg, thus causing fatal unmap of some erroneous address. Fix it by duplicating *sg_ptr for iterating. Signed-off-by: wwang Signed-off-by: Greg Kroah-Hartman Signed-off-by: Keng-Yu Lin --- drivers/staging/rts_pstor/rtsx_transport.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) diff --git a/drivers/staging/rts_pstor/rtsx_transport.c b/drivers/staging/rts_pstor/rtsx_transport.c index 4e3d2c1..9b2e5c9 100644 --- a/drivers/staging/rts_pstor/rtsx_transport.c +++ b/drivers/staging/rts_pstor/rtsx_transport.c @@ -335,6 +335,7 @@ static int rtsx_transfer_sglist_adma_partial(struct rtsx_chip *chip, u8 card, int sg_cnt, i, resid; int err = 0; long timeleft; + struct scatterlist *sg_ptr; u32 val = TRIG_DMA; if ((sg == NULL) || (num_sg <= 0) || !offset || !index) @@ -371,7 +372,7 @@ static int rtsx_transfer_sglist_adma_partial(struct rtsx_chip *chip, u8 card, sg_cnt = dma_map_sg(&(rtsx->pci->dev), sg, num_sg, dma_dir); resid = size; - + sg_ptr = sg; chip->sgi = 0; /* Usually the next entry will be @sg@ + 1, but if this sg element * is part of a chained scatterlist, it could jump to the start of @@ -379,14 +380,14 @@ static int rtsx_transfer_sglist_adma_partial(struct rtsx_chip *chip, u8 card, * the proper sg */ for (i = 0; i < *index; i++) - sg = sg_next(sg); + sg_ptr = sg_next(sg_ptr); for (i = *index; i < sg_cnt; i++) { dma_addr_t addr; unsigned int len; u8 option; - addr = sg_dma_address(sg); - len = sg_dma_len(sg); + addr = sg_dma_address(sg_ptr); + len = sg_dma_len(sg_ptr); RTSX_DEBUGP("DMA addr: 0x%x, Len: 0x%x\n", (unsigned int)addr, len); @@ -415,7 +416,7 @@ static int rtsx_transfer_sglist_adma_partial(struct rtsx_chip *chip, u8 card, if (!resid) break; - sg = sg_next(sg); + sg_ptr = sg_next(sg_ptr); } RTSX_DEBUGP("SG table count = %d\n", chip->sgi); -- 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/