6.13-stable review patch. If anyone has any objections, please let me know.
------------------
From: Chen Ridong <chenridong@xxxxxxxxxx>
[ Upstream commit dd7d37ccf6b11f3d95e797ebe4e9e886d0332600 ]
Although the previous patch can avoid ps and ps UAF for _do_serial, it
can not avoid potential UAF issue for reorder_work. This issue can
happen just as below:
crypto_request crypto_request crypto_del_alg
padata_do_serial
...
padata_reorder
// processes all remaining
// requests then breaks
while (1) {
if (!padata)
break;
...
}
padata_do_serial
// new request added
list_add
// sees the new request
queue_work(reorder_work)
padata_reorder
queue_work_on(squeue->work)
...
<kworker context>
padata_serial_worker
// completes new request,
// no more outstanding
// requests
crypto_del_alg
// free pd
<kworker context>
invoke_padata_reorder
// UAF of pd
To avoid UAF for 'reorder_work', get 'pd' ref before put 'reorder_work'
into the 'serial_wq' and put 'pd' ref until the 'serial_wq' finish.
Fixes: bbefa1dd6a6d ("crypto: pcrypt - Avoid deadlock by using per-instance padata queues")
Signed-off-by: Chen Ridong <chenridong@xxxxxxxxxx>
Acked-by: Daniel Jordan <daniel.m.jordan@xxxxxxxxxx>
Signed-off-by: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
kernel/padata.c | 10 +++++++++-
1 file changed, 9 insertions(+), 1 deletion(-)
diff --git a/kernel/padata.c b/kernel/padata.c
index de2c02a81469c..418987056340e 100644
--- a/kernel/padata.c
+++ b/kernel/padata.c
@@ -352,8 +352,14 @@ static void padata_reorder(struct parallel_data *pd)
smp_mb();
reorder = per_cpu_ptr(pd->reorder_list, pd->cpu);
- if (!list_empty(&reorder->list) && padata_find_next(pd, false))
+ if (!list_empty(&reorder->list) && padata_find_next(pd, false)) {
+ /*
+ * Other context(eg. the padata_serial_worker) can finish the request.
+ * To avoid UAF issue, add pd ref here, and put pd ref after reorder_work finish.
+ */
+ padata_get_pd(pd);
queue_work(pinst->serial_wq, &pd->reorder_work);
+ }
}
static void invoke_padata_reorder(struct work_struct *work)
@@ -364,6 +370,8 @@ static void invoke_padata_reorder(struct work_struct *work)
pd = container_of(work, struct parallel_data, reorder_work);
padata_reorder(pd);
local_bh_enable();
+ /* Pairs with putting the reorder_work in the serial_wq */
+ padata_put_pd(pd);
}
static void padata_serial_worker(struct work_struct *serial_work)
--
2.39.5
