lkml.org 
[lkml]   [2018]   [Oct]   [30]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH v2] xen-blkfront: fix kernel panic with negotiate_mq error path
    Date
    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>
    ---
    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 429d201..5d84da2 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;
    }

    --
    1.7.1
    \
     
     \ /
      Last update: 2018-10-30 17:49    [W:3.081 / U:0.268 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site