Commit 2226f959 authored by Kal Conley's avatar Kal Conley Committed by Greg Kroah-Hartman
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net/packet: fix 4gb buffer limit due to overflow check

[ Upstream commit fc62814d ]

When calculating rb->frames_per_block * req->tp_block_nr the result
can overflow. Check it for overflow without limiting the total buffer
size to UINT_MAX.

This change fixes support for packet ring buffers >= UINT_MAX.

Fixes: 8f8d28e4

 ("net/packet: fix overflow in check for tp_frame_nr")
Signed-off-by: default avatarKal Conley <>
Signed-off-by: default avatarDavid S. Miller <>
Signed-off-by: default avatarGreg Kroah-Hartman <>
parent 7c3969ff
...@@ -4313,7 +4313,7 @@ static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u, ...@@ -4313,7 +4313,7 @@ static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u,
rb->frames_per_block = req->tp_block_size / req->tp_frame_size; rb->frames_per_block = req->tp_block_size / req->tp_frame_size;
if (unlikely(rb->frames_per_block == 0)) if (unlikely(rb->frames_per_block == 0))
goto out; goto out;
if (unlikely(req->tp_block_size > UINT_MAX / req->tp_block_nr)) if (unlikely(rb->frames_per_block > UINT_MAX / req->tp_block_nr))
goto out; goto out;
if (unlikely((rb->frames_per_block * req->tp_block_nr) != if (unlikely((rb->frames_per_block * req->tp_block_nr) !=
req->tp_frame_nr)) req->tp_frame_nr))
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