Re: [Xen-devel] [PATCH 1/2] xen/blkback: Copy id field when doing BLKIF_DISCARD.
From: Stefano Stabellini <hidden>
Date: 2012-05-28 10:19:42
Also in:
xen-devel
On Fri, 25 May 2012, Konrad Rzeszutek Wilk wrote:
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 Signed-off-by: Konrad Rzeszutek Wilk <redacted>
Acked-by: Stefano Stabellini <redacted>
quoted hunk ↗ jump to hunk
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 773cf27..9ad3b5e 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;-- 1.7.7.6 _______________________________________________ Xen-devel mailing list Xen-devel@lists.xen.org http://lists.xen.org/xen-devel