This is a note to let you know that I've just added the patch titled xen-gnt: prevent adding duplicate gnt callbacks to the 3.10-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: xen-gnt-prevent-adding-duplicate-gnt-callbacks.patch and it can be found in the queue-3.10 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 5f338d9001094a56cf87bd8a280b4e7ff953bb59 Mon Sep 17 00:00:00 2001 From: Roger Pau Monne <roger.pau@xxxxxxxxxx> Date: Wed, 31 Jul 2013 17:00:42 +0200 Subject: xen-gnt: prevent adding duplicate gnt callbacks From: Roger Pau Monne <roger.pau@xxxxxxxxxx> commit 5f338d9001094a56cf87bd8a280b4e7ff953bb59 upstream. With the current implementation, the callback in the tail of the list can be added twice, because the check done in gnttab_request_free_callback is bogus, callback->next can be NULL if it is the last callback in the list. If we add the same callback twice we end up with an infinite loop, were callback == callback->next. Replace this check with a proper one that iterates over the list to see if the callback has already been added. Signed-off-by: Roger Pau Monné <roger.pau@xxxxxxxxxx> Cc: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx> Cc: David Vrabel <david.vrabel@xxxxxxxxxx> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx> Acked-by: Matt Wilson <msw@xxxxxxxxxx> Reviewed-by: David Vrabel <david.vrabel@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/xen/grant-table.c | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-) --- a/drivers/xen/grant-table.c +++ b/drivers/xen/grant-table.c @@ -729,9 +729,18 @@ void gnttab_request_free_callback(struct void (*fn)(void *), void *arg, u16 count) { unsigned long flags; + struct gnttab_free_callback *cb; + spin_lock_irqsave(&gnttab_list_lock, flags); - if (callback->next) - goto out; + + /* Check if the callback is already on the list */ + cb = gnttab_free_callback_list; + while (cb) { + if (cb == callback) + goto out; + cb = cb->next; + } + callback->fn = fn; callback->arg = arg; callback->count = count; Patches currently in stable-queue which might be from roger.pau@xxxxxxxxxx are queue-3.10/xen-gnt-prevent-adding-duplicate-gnt-callbacks.patch -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html