5.10-stable review patch. If anyone has any objections, please let me know.
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From: Xiyu Yang xiyuyang19@fudan.edu.cn
[ Upstream commit d5ee8e750c9449e9849a09ce6fb6b8adeaa66adc ]
refcount_t type and corresponding API can protect refcounters from accidental underflow and overflow and further use-after-free situations.
Signed-off-by: Xiyu Yang xiyuyang19@fudan.edu.cn Signed-off-by: Xin Tan tanxin.ctf@gmail.com Acked-by: Daniel Jordan daniel.m.jordan@oracle.com Signed-off-by: Herbert Xu herbert@gondor.apana.org.au Stable-dep-of: 7ddc21e317b3 ("padata: Fix refcnt handling in padata_free_shell()") Signed-off-by: Sasha Levin sashal@kernel.org --- include/linux/padata.h | 3 ++- kernel/padata.c | 8 ++++---- 2 files changed, 6 insertions(+), 5 deletions(-)
diff --git a/include/linux/padata.h b/include/linux/padata.h index a433f13fc4bf7..495b16b6b4d72 100644 --- a/include/linux/padata.h +++ b/include/linux/padata.h @@ -12,6 +12,7 @@ #ifndef PADATA_H #define PADATA_H
+#include <linux/refcount.h> #include <linux/compiler_types.h> #include <linux/workqueue.h> #include <linux/spinlock.h> @@ -96,7 +97,7 @@ struct parallel_data { struct padata_shell *ps; struct padata_list __percpu *reorder_list; struct padata_serial_queue __percpu *squeue; - atomic_t refcnt; + refcount_t refcnt; unsigned int seq_nr; unsigned int processed; int cpu; diff --git a/kernel/padata.c b/kernel/padata.c index 11ca3ebd8b123..dc81c756da3d9 100644 --- a/kernel/padata.c +++ b/kernel/padata.c @@ -211,7 +211,7 @@ int padata_do_parallel(struct padata_shell *ps, if ((pinst->flags & PADATA_RESET)) goto out;
- atomic_inc(&pd->refcnt); + refcount_inc(&pd->refcnt); padata->pd = pd; padata->cb_cpu = *cb_cpu;
@@ -385,7 +385,7 @@ static void padata_serial_worker(struct work_struct *serial_work) } local_bh_enable();
- if (atomic_sub_and_test(cnt, &pd->refcnt)) + if (refcount_sub_and_test(cnt, &pd->refcnt)) padata_free_pd(pd); }
@@ -598,7 +598,7 @@ static struct parallel_data *padata_alloc_pd(struct padata_shell *ps) padata_init_reorder_list(pd); padata_init_squeues(pd); pd->seq_nr = -1; - atomic_set(&pd->refcnt, 1); + refcount_set(&pd->refcnt, 1); spin_lock_init(&pd->lock); pd->cpu = cpumask_first(pd->cpumask.pcpu); INIT_WORK(&pd->reorder_work, invoke_padata_reorder); @@ -672,7 +672,7 @@ static int padata_replace(struct padata_instance *pinst) synchronize_rcu();
list_for_each_entry_continue_reverse(ps, &pinst->pslist, list) - if (atomic_dec_and_test(&ps->opd->refcnt)) + if (refcount_dec_and_test(&ps->opd->refcnt)) padata_free_pd(ps->opd);
pinst->flags &= ~PADATA_RESET;