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authorDaniel Jordan <daniel.m.jordan@oracle.com>2020-04-21 19:34:55 +0300
committerHerbert Xu <herbert@gondor.apana.org.au>2020-04-30 08:19:33 +0300
commit3c2214b6027ff37945799de717c417212e1a8c54 (patch)
treea4fa09b5b3414a84465ab70f7fd525ce914a3bf9 /include/linux/padata.h
parentb2d7e8bcaab7d1d931369984e2bae952247a1412 (diff)
downloadlinux-3c2214b6027ff37945799de717c417212e1a8c54.tar.xz
padata: add separate cpuhp node for CPUHP_PADATA_DEAD
Removing the pcrypt module triggers this: general protection fault, probably for non-canonical address 0xdead000000000122 CPU: 5 PID: 264 Comm: modprobe Not tainted 5.6.0+ #2 Hardware name: QEMU Standard PC RIP: 0010:__cpuhp_state_remove_instance+0xcc/0x120 Call Trace: padata_sysfs_release+0x74/0xce kobject_put+0x81/0xd0 padata_free+0x12/0x20 pcrypt_exit+0x43/0x8ee [pcrypt] padata instances wrongly use the same hlist node for the online and dead states, so __padata_free()'s second cpuhp remove call chokes on the node that the first poisoned. cpuhp multi-instance callbacks only walk forward in cpuhp_step->list and the same node is linked in both the online and dead lists, so the list corruption that results from padata_alloc() adding the node to a second list without removing it from the first doesn't cause problems as long as no instances are freed. Avoid the issue by giving each state its own node. Fixes: 894c9ef9780c ("padata: validate cpumask without removed CPU during offline") Signed-off-by: Daniel Jordan <daniel.m.jordan@oracle.com> Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: Steffen Klassert <steffen.klassert@secunet.com> Cc: linux-crypto@vger.kernel.org Cc: linux-kernel@vger.kernel.org Cc: stable@vger.kernel.org # v5.4+ Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Diffstat (limited to 'include/linux/padata.h')
-rw-r--r--include/linux/padata.h6
1 files changed, 4 insertions, 2 deletions
diff --git a/include/linux/padata.h b/include/linux/padata.h
index a0d8b41850b2..693cae9bfe66 100644
--- a/include/linux/padata.h
+++ b/include/linux/padata.h
@@ -139,7 +139,8 @@ struct padata_shell {
/**
* struct padata_instance - The overall control structure.
*
- * @node: Used by CPU hotplug.
+ * @cpu_online_node: Linkage for CPU online callback.
+ * @cpu_dead_node: Linkage for CPU offline callback.
* @parallel_wq: The workqueue used for parallel work.
* @serial_wq: The workqueue used for serial work.
* @pslist: List of padata_shell objects attached to this instance.
@@ -150,7 +151,8 @@ struct padata_shell {
* @flags: padata flags.
*/
struct padata_instance {
- struct hlist_node node;
+ struct hlist_node cpu_online_node;
+ struct hlist_node cpu_dead_node;
struct workqueue_struct *parallel_wq;
struct workqueue_struct *serial_wq;
struct list_head pslist;