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author | Daniel Jordan <daniel.m.jordan@oracle.com> | 2020-04-21 12:34:55 -0400 |
---|---|---|
committer | Herbert Xu <herbert@gondor.apana.org.au> | 2020-04-30 15:19:33 +1000 |
commit | 3c2214b6027ff37945799de717c417212e1a8c54 (patch) | |
tree | a4fa09b5b3414a84465ab70f7fd525ce914a3bf9 | |
parent | b2d7e8bcaab7d1d931369984e2bae952247a1412 (diff) | |
download | linux-3c2214b6027ff37945799de717c417212e1a8c54.tar.bz2 |
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>
-rw-r--r-- | include/linux/padata.h | 6 | ||||
-rw-r--r-- | kernel/padata.c | 14 |
2 files changed, 12 insertions, 8 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; diff --git a/kernel/padata.c b/kernel/padata.c index a6afa12fb75e..aae789896616 100644 --- a/kernel/padata.c +++ b/kernel/padata.c @@ -703,7 +703,7 @@ static int padata_cpu_online(unsigned int cpu, struct hlist_node *node) struct padata_instance *pinst; int ret; - pinst = hlist_entry_safe(node, struct padata_instance, node); + pinst = hlist_entry_safe(node, struct padata_instance, cpu_online_node); if (!pinst_has_cpu(pinst, cpu)) return 0; @@ -718,7 +718,7 @@ static int padata_cpu_dead(unsigned int cpu, struct hlist_node *node) struct padata_instance *pinst; int ret; - pinst = hlist_entry_safe(node, struct padata_instance, node); + pinst = hlist_entry_safe(node, struct padata_instance, cpu_dead_node); if (!pinst_has_cpu(pinst, cpu)) return 0; @@ -734,8 +734,9 @@ static enum cpuhp_state hp_online; static void __padata_free(struct padata_instance *pinst) { #ifdef CONFIG_HOTPLUG_CPU - cpuhp_state_remove_instance_nocalls(CPUHP_PADATA_DEAD, &pinst->node); - cpuhp_state_remove_instance_nocalls(hp_online, &pinst->node); + cpuhp_state_remove_instance_nocalls(CPUHP_PADATA_DEAD, + &pinst->cpu_dead_node); + cpuhp_state_remove_instance_nocalls(hp_online, &pinst->cpu_online_node); #endif WARN_ON(!list_empty(&pinst->pslist)); @@ -939,9 +940,10 @@ static struct padata_instance *padata_alloc(const char *name, mutex_init(&pinst->lock); #ifdef CONFIG_HOTPLUG_CPU - cpuhp_state_add_instance_nocalls_cpuslocked(hp_online, &pinst->node); + cpuhp_state_add_instance_nocalls_cpuslocked(hp_online, + &pinst->cpu_online_node); cpuhp_state_add_instance_nocalls_cpuslocked(CPUHP_PADATA_DEAD, - &pinst->node); + &pinst->cpu_dead_node); #endif put_online_cpus(); |