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: 7ed8ce1c ("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>
parent
d9cccfa7
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