[PATCH 6.1 503/609] bpf: tcp: Make mem flags configurable through bpf_iter_tcp_realloc_batch

6.1-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Jordan Rife <[email protected]>

[ Upstream commit 8271bec9fc1cfe522b1a18cacbefd6712a3d41c2 ]

Prepare for the next patch which needs to be able to choose either
GFP_USER or GFP_NOWAIT for calls to bpf_iter_tcp_realloc_batch.

Signed-off-by: Jordan Rife <[email protected]>
Signed-off-by: Martin KaFai Lau <[email protected]>
Reviewed-by: Kuniyuki Iwashima <[email protected]>
Acked-by: Stanislav Fomichev <[email protected]>
Stable-dep-of: e5fd3f514e27 ("bpf: tcp: Fix use-after-free in bpf_iter_tcp_established_batch()")
Signed-off-by: Sasha Levin <[email protected]>
---
 net/ipv4/tcp_ipv4.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 89200b4314018..7823e55bc9e73 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -2759,12 +2759,12 @@ static void bpf_iter_tcp_put_batch(struct bpf_tcp_iter_state *iter)
 }
 
 static int bpf_iter_tcp_realloc_batch(struct bpf_tcp_iter_state *iter,
-				      unsigned int new_batch_sz)
+				      unsigned int new_batch_sz, gfp_t flags)
 {
 	struct sock **new_batch;
 
 	new_batch = kvmalloc(sizeof(*new_batch) * new_batch_sz,
-			     GFP_USER | __GFP_NOWARN);
+			     flags | __GFP_NOWARN);
 	if (!new_batch)
 		return -ENOMEM;
 
@@ -2876,7 +2876,8 @@ static struct sock *bpf_iter_tcp_batch(struct seq_file *seq)
 		return sk;
 	}
 
-	if (!resized && !bpf_iter_tcp_realloc_batch(iter, expected * 3 / 2)) {
+	if (!resized && !bpf_iter_tcp_realloc_batch(iter, expected * 3 / 2,
+						    GFP_USER)) {
 		resized = true;
 		goto again;
 	}
@@ -3293,7 +3294,7 @@ static int bpf_iter_init_tcp(void *priv_data, struct bpf_iter_aux_info *aux)
 	if (err)
 		return err;
 
-	err = bpf_iter_tcp_realloc_batch(iter, INIT_BATCH_SZ);
+	err = bpf_iter_tcp_realloc_batch(iter, INIT_BATCH_SZ, GFP_USER);
 	if (err) {
 		bpf_iter_fini_seq_net(priv_data);
 		return err;
-- 
2.53.0