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55 lines
2.1 KiB
55 lines
2.1 KiB
From 8c9ce606a60e4a0cb447bdc082ce383b96b227b4 Mon Sep 17 00:00:00 2001
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From: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
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Date: Fri, 25 May 2012 16:11:09 -0400
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Subject: [PATCH 2/3] xen/blkback: Copy id field when doing BLKIF_DISCARD.
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We weren't copying the id field so when we sent the response
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back to the frontend (especially with a 64-bit host and 32-bit
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guest), we ended up using a random value. This lead to the
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frontend crashing as it would try to pass to __blk_end_request_all
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a NULL 'struct request' (b/c it would use the 'id' to find the
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proper 'struct request' in its shadow array) and end up crashing:
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BUG: unable to handle kernel NULL pointer dereference at 000000e4
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IP: [<c0646d4c>] __blk_end_request_all+0xc/0x40
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.. snip..
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EIP is at __blk_end_request_all+0xc/0x40
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.. snip..
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[<ed95db72>] blkif_interrupt+0x172/0x330 [xen_blkfront]
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This fixes the bug by passing in the proper id for the response.
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Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=824641
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CC: stable@kernel.org
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Tested-by: William Dauchy <wdauchy@gmail.com>
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Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
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Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
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---
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drivers/block/xen-blkback/common.h | 2 ++
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1 files changed, 2 insertions(+), 0 deletions(-)
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diff --git a/drivers/block/xen-blkback/common.h b/drivers/block/xen-blkback/common.h
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index 773cf27..9ad3b5e 100644
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--- a/drivers/block/xen-blkback/common.h
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+++ b/drivers/block/xen-blkback/common.h
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@@ -257,6 +257,7 @@ static inline void blkif_get_x86_32_req(struct blkif_request *dst,
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break;
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case BLKIF_OP_DISCARD:
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dst->u.discard.flag = src->u.discard.flag;
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+ dst->u.discard.id = src->u.discard.id;
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dst->u.discard.sector_number = src->u.discard.sector_number;
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dst->u.discard.nr_sectors = src->u.discard.nr_sectors;
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break;
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@@ -287,6 +288,7 @@ static inline void blkif_get_x86_64_req(struct blkif_request *dst,
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break;
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case BLKIF_OP_DISCARD:
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dst->u.discard.flag = src->u.discard.flag;
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+ dst->u.discard.id = src->u.discard.id;
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dst->u.discard.sector_number = src->u.discard.sector_number;
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dst->u.discard.nr_sectors = src->u.discard.nr_sectors;
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break;
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--
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1.7.4.4
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