| Message ID | 20190531092923.4874-1-wangkefeng.wang@huawei.com (mailing list archive) |
|---|---|
| State | Changes Requested |
| Delegated to: | Herbert Xu |
| Headers | show |
| Series | crypto: pcrypt: Fix possible deadlock in padata_sysfs_release | expand |
On 2019/5/31 17:29, Kefeng Wang wrote: > There is a deadlock issue in pcrypt_init_padata(), > > pcrypt_init_padata() > cpus_read_lock() > padata_free() > padata_sysfs_release() > cpus_read_lock() > > Narrow rcu_read_lock/unlock() and move put_online_cpus() > before padata_free() to fix it. > > Reported-by: Hulk Robot <hulkci@huawei.com> > Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> > --- > crypto/pcrypt.c | 6 +++--- > 1 file changed, 3 insertions(+), 3 deletions(-) > > diff --git a/crypto/pcrypt.c b/crypto/pcrypt.c > index 0e9ce329fd47..662228b48b70 100644 > --- a/crypto/pcrypt.c > +++ b/crypto/pcrypt.c > @@ -407,13 +407,14 @@ static int pcrypt_init_padata(struct padata_pcrypt *pcrypt, > int ret = -ENOMEM; > struct pcrypt_cpumask *mask; > > - get_online_cpus(); > > pcrypt->wq = alloc_workqueue("%s", WQ_MEM_RECLAIM | WQ_CPU_INTENSIVE, > 1, name); > if (!pcrypt->wq) > goto err; > > + get_online_cpus(); > + > pcrypt->pinst = padata_alloc_possible(pcrypt->wq); > if (!pcrypt->pinst) Oh, forget to add put_online_cpus in this error path, will resend v2 if there is no comment. > goto err_destroy_workqueue; > @@ -448,12 +449,11 @@ static int pcrypt_init_padata(struct padata_pcrypt *pcrypt, > free_cpumask_var(mask->mask); > kfree(mask); > err_free_padata: > + put_online_cpus(); > padata_free(pcrypt->pinst); > err_destroy_workqueue: > destroy_workqueue(pcrypt->wq); > err: > - put_online_cpus(); > - > return ret; > } >
diff --git a/crypto/pcrypt.c b/crypto/pcrypt.c index 0e9ce329fd47..662228b48b70 100644 --- a/crypto/pcrypt.c +++ b/crypto/pcrypt.c @@ -407,13 +407,14 @@ static int pcrypt_init_padata(struct padata_pcrypt *pcrypt, int ret = -ENOMEM; struct pcrypt_cpumask *mask; - get_online_cpus(); pcrypt->wq = alloc_workqueue("%s", WQ_MEM_RECLAIM | WQ_CPU_INTENSIVE, 1, name); if (!pcrypt->wq) goto err; + get_online_cpus(); + pcrypt->pinst = padata_alloc_possible(pcrypt->wq); if (!pcrypt->pinst) goto err_destroy_workqueue; @@ -448,12 +449,11 @@ static int pcrypt_init_padata(struct padata_pcrypt *pcrypt, free_cpumask_var(mask->mask); kfree(mask); err_free_padata: + put_online_cpus(); padata_free(pcrypt->pinst); err_destroy_workqueue: destroy_workqueue(pcrypt->wq); err: - put_online_cpus(); - return ret; }
There is a deadlock issue in pcrypt_init_padata(), pcrypt_init_padata() cpus_read_lock() padata_free() padata_sysfs_release() cpus_read_lock() Narrow rcu_read_lock/unlock() and move put_online_cpus() before padata_free() to fix it. Reported-by: Hulk Robot <hulkci@huawei.com> Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> --- crypto/pcrypt.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)