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| author | Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> | 2012-05-25 22:11:09 +0200 |
|---|---|---|
| committer | Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> | 2012-05-30 23:20:04 +0200 |
| commit | 8c9ce606a60e4a0cb447bdc082ce383b96b227b4 (patch) | |
| tree | 75fccf7e0e44f2b863c951e013b17dc215461701 /drivers | |
| parent | xen-blkfront: module exit handling adjustments (diff) | |
| download | linux-8c9ce606a60e4a0cb447bdc082ce383b96b227b4.tar.xz linux-8c9ce606a60e4a0cb447bdc082ce383b96b227b4.zip | |
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')
| -rw-r--r-- | drivers/block/xen-blkback/common.h | 2 |
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; |