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| author |   Manjunath Patil <manjunath.b.patil@oracle.com> | 2018-10-30 09:49:21 -0700 |
|---|---|---|
| committer |   Juergen Gross <jgross@suse.com> | 2018-11-06 10:33:36 +0100 |
| commit | 6cc4a0863c9709c512280c64e698d68443ac8053 (patch) | |
| tree | dc10a971c18a294f2fed2dcbdfb5fd89d0977bc9 /drivers/block/xen-blkfront.c | |
| parent | xen/grant-table: Fix incorrect gnttab_dma_free_pages() pr_debug message (diff) | |
| download | linux-dev-6cc4a0863c9709c512280c64e698d68443ac8053.tar.xz linux-dev-6cc4a0863c9709c512280c64e698d68443ac8053.zip | |
xen-blkfront: fix kernel panic with negotiate_mq error path
info->nr_rings isn't adjusted in case of ENOMEM error from
negotiate_mq(). This leads to kernel panic in error path.
Typical call stack involving panic -
#8 page_fault at ffffffff8175936f
[exception RIP: blkif_free_ring+33]
RIP: ffffffffa0149491 RSP: ffff8804f7673c08 RFLAGS: 00010292
...
#9 blkif_free at ffffffffa0149aaa [xen_blkfront]
#10 talk_to_blkback at ffffffffa014c8cd [xen_blkfront]
#11 blkback_changed at ffffffffa014ea8b [xen_blkfront]
#12 xenbus_otherend_changed at ffffffff81424670
#13 backend_changed at ffffffff81426dc3
#14 xenwatch_thread at ffffffff81422f29
#15 kthread at ffffffff810abe6a
#16 ret_from_fork at ffffffff81754078
Cc: stable@vger.kernel.org
Fixes: 7ed8ce1c5fc7 ("xen-blkfront: move negotiate_mq to cover all cases of new VBDs")
Signed-off-by: Manjunath Patil <manjunath.b.patil@oracle.com>
Acked-by: Roger Pau Monné <roger.pau@citrix.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Diffstat (limited to 'drivers/block/xen-blkfront.c')
| -rw-r--r-- | drivers/block/xen-blkfront.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c index 9eea83ae01c6..9ac3999a55b7 100644 --- a/drivers/block/xen-blkfront.c +++ b/drivers/block/xen-blkfront.c @@ -1919,6 +1919,7 @@ static int negotiate_mq(struct blkfront_info *info) GFP_KERNEL); if (!info->rinfo) { xenbus_dev_fatal(info->xbdev, -ENOMEM, "allocating ring_info structure"); + info->nr_rings = 0; return -ENOMEM; } |