Re: [syzbot] Re: [syzbot] [bpf?] [net?] general protection fault in __xsk_map_flush

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Subject: Re: [syzbot] [bpf?] [net?] general protection fault in __xsk_map_flush
Author: aha310510@gmail.com

#syz test git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master

---
 include/linux/filter.h | 6 +++---
 kernel/bpf/cpumap.c    | 2 +-
 kernel/bpf/devmap.c    | 2 +-
 3 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/include/linux/filter.h b/include/linux/filter.h
index b6672ff61407..22691015d175 100644
--- a/include/linux/filter.h
+++ b/include/linux/filter.h
@@ -842,15 +842,15 @@ static inline void bpf_net_ctx_get_all_used_flush_lists(struct list_head **lh_ma
 	if (!IS_ENABLED(CONFIG_BPF_SYSCALL))
 		return;
 
-	lh = &bpf_net_ctx->dev_map_flush_list;
+	lh = this_cpu_ptr(&bpf_net_ctx->dev_map_flush_list);
 	if (kern_flags & BPF_RI_F_DEV_MAP_INIT && !list_empty(lh))
 		*lh_dev = lh;
 
-	lh = &bpf_net_ctx->cpu_map_flush_list;
+	lh = this_cpu_ptr(&bpf_net_ctx->cpu_map_flush_list);
 	if (kern_flags & BPF_RI_F_CPU_MAP_INIT && !list_empty(lh))
 		*lh_map = lh;
 
-	lh = &bpf_net_ctx->xskmap_map_flush_list;
+	lh = this_cpu_ptr(&bpf_net_ctx->xskmap_map_flush_list);
 	if (IS_ENABLED(CONFIG_XDP_SOCKETS) &&
 	    kern_flags & BPF_RI_F_XSK_MAP_INIT && !list_empty(lh))
 		*lh_xsk = lh;
diff --git a/kernel/bpf/cpumap.c b/kernel/bpf/cpumap.c
index fbdf5a1aabfe..8fccc311397c 100644
--- a/kernel/bpf/cpumap.c
+++ b/kernel/bpf/cpumap.c
@@ -676,7 +676,7 @@ static void bq_flush_to_queue(struct xdp_bulk_queue *bq)
 	struct ptr_ring *q;
 	int i;
 
-	if (unlikely(!bq->count))
+	if (unlikely(!bq->count) || unlikely(bq->count) > CPU_MAP_BULK_SIZE)
 		return;
 
 	q = rcpu->queue;
diff --git a/kernel/bpf/devmap.c b/kernel/bpf/devmap.c
index 9e0e3b0a18e4..4b9203deb711 100644
--- a/kernel/bpf/devmap.c
+++ b/kernel/bpf/devmap.c
@@ -378,7 +378,7 @@ static void bq_xmit_all(struct xdp_dev_bulk_queue *bq, u32 flags)
 	int to_send = cnt;
 	int i;
 
-	if (unlikely(!cnt))
+	if (unlikely(!cnt) || unlikely(cnt) > DEV_MAP_BULK_SIZE)
 		return;
 
 	for (i = 0; i < cnt; i++) {
--