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authorKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>2012-05-25 16:11:09 -0400
committerKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>2012-05-30 17:20:04 -0400
commit8c9ce606a60e4a0cb447bdc082ce383b96b227b4 (patch)
tree75fccf7e0e44f2b863c951e013b17dc215461701 /drivers/block/xen-blkback
parent8605067fb9b8e34aecf44ec258657c9cc009fc5a (diff)
xen/blkback: Copy id field when doing BLKIF_DISCARD.
We weren't copying the id field so when we sent the response back to the frontend (especially with a 64-bit host and 32-bit guest), we ended up using a random value. This lead to the frontend crashing as it would try to pass to __blk_end_request_all a NULL 'struct request' (b/c it would use the 'id' to find the proper 'struct request' in its shadow array) and end up crashing: BUG: unable to handle kernel NULL pointer dereference at 000000e4 IP: [<c0646d4c>] __blk_end_request_all+0xc/0x40 .. snip.. EIP is at __blk_end_request_all+0xc/0x40 .. snip.. [<ed95db72>] blkif_interrupt+0x172/0x330 [xen_blkfront] This fixes the bug by passing in the proper id for the response. Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=824641 CC: stable@kernel.org Tested-by: William Dauchy <wdauchy@gmail.com> Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Diffstat (limited to 'drivers/block/xen-blkback')
-rw-r--r--drivers/block/xen-blkback/common.h2
1 files changed, 2 insertions, 0 deletions
diff --git a/drivers/block/xen-blkback/common.h b/drivers/block/xen-blkback/common.h
index 773cf27dc23f..9ad3b5ec1dc1 100644
--- a/drivers/block/xen-blkback/common.h
+++ b/drivers/block/xen-blkback/common.h
@@ -257,6 +257,7 @@ static inline void blkif_get_x86_32_req(struct blkif_request *dst,
break;
case BLKIF_OP_DISCARD:
dst->u.discard.flag = src->u.discard.flag;
+ dst->u.discard.id = src->u.discard.id;
dst->u.discard.sector_number = src->u.discard.sector_number;
dst->u.discard.nr_sectors = src->u.discard.nr_sectors;
break;
@@ -287,6 +288,7 @@ static inline void blkif_get_x86_64_req(struct blkif_request *dst,
break;
case BLKIF_OP_DISCARD:
dst->u.discard.flag = src->u.discard.flag;
+ dst->u.discard.id = src->u.discard.id;
dst->u.discard.sector_number = src->u.discard.sector_number;
dst->u.discard.nr_sectors = src->u.discard.nr_sectors;
break;