From: Daniel Jordan daniel.m.jordan@oracle.com
[ Upstream commit 57ddfecc72a6c9941d159543e1c0c0a74fe9afdd ]
list_for_each_entry_reverse() assumes that the iterated list is nonempty and that every list_head is embedded in the same type, but its use in padata_do_serial() breaks both rules.
This doesn't cause any issues now because padata_priv and padata_list happen to have their list fields at the same offset, but we really shouldn't be relying on that.
Fixes: bfde23ce200e ("padata: unbind parallel jobs from specific CPUs") Signed-off-by: Daniel Jordan daniel.m.jordan@oracle.com Signed-off-by: Herbert Xu herbert@gondor.apana.org.au Signed-off-by: Sasha Levin sashal@kernel.org --- kernel/padata.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/kernel/padata.c b/kernel/padata.c index 4d31a69a9b38..11ca3ebd8b12 100644 --- a/kernel/padata.c +++ b/kernel/padata.c @@ -403,13 +403,16 @@ void padata_do_serial(struct padata_priv *padata) int hashed_cpu = padata_cpu_hash(pd, padata->seq_nr); struct padata_list *reorder = per_cpu_ptr(pd->reorder_list, hashed_cpu); struct padata_priv *cur; + struct list_head *pos;
spin_lock(&reorder->lock); /* Sort in ascending order of sequence number. */ - list_for_each_entry_reverse(cur, &reorder->list, list) + list_for_each_prev(pos, &reorder->list) { + cur = list_entry(pos, struct padata_priv, list); if (cur->seq_nr < padata->seq_nr) break; - list_add(&padata->list, &cur->list); + } + list_add(&padata->list, pos); spin_unlock(&reorder->lock);
/*