51 lines
1.7 KiB
Diff
51 lines
1.7 KiB
Diff
From 8460e3230988ef2ec13ce6b69b687e941f6cdb32 Mon Sep 17 00:00:00 2001
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From: Jouni Malinen <jouni@codeaurora.org>
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Date: Tue, 8 Dec 2020 23:52:50 +0200
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Subject: [PATCH] P2P: Fix a corner case in peer addition based on PD Request
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p2p_add_device() may remove the oldest entry if there is no room in the
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peer table for a new peer. This would result in any pointer to that
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removed entry becoming stale. A corner case with an invalid PD Request
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frame could result in such a case ending up using (read+write) freed
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memory. This could only by triggered when the peer table has reached its
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maximum size and the PD Request frame is received from the P2P Device
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Address of the oldest remaining entry and the frame has incorrect P2P
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Device Address in the payload.
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Fix this by fetching the dev pointer again after having called
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p2p_add_device() so that the stale pointer cannot be used.
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Fixes: 17bef1e97a50 ("P2P: Add peer entry based on Provision Discovery Request")
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Signed-off-by: Jouni Malinen <jouni@codeaurora.org>
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---
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src/p2p/p2p_pd.c | 12 +++++-------
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1 file changed, 5 insertions(+), 7 deletions(-)
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diff --git a/src/p2p/p2p_pd.c b/src/p2p/p2p_pd.c
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index 3994ec03f86b..05fd593494ef 100644
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--- a/src/p2p/p2p_pd.c
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+++ b/src/p2p/p2p_pd.c
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@@ -595,14 +595,12 @@ void p2p_process_prov_disc_req(struct p2p_data *p2p, const u8 *sa,
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goto out;
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}
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+ dev = p2p_get_device(p2p, sa);
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if (!dev) {
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- dev = p2p_get_device(p2p, sa);
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- if (!dev) {
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- p2p_dbg(p2p,
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- "Provision Discovery device not found "
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- MACSTR, MAC2STR(sa));
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- goto out;
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- }
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+ p2p_dbg(p2p,
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+ "Provision Discovery device not found "
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+ MACSTR, MAC2STR(sa));
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+ goto out;
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}
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} else if (msg.wfd_subelems) {
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wpabuf_free(dev->info.wfd_subelems);
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--
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2.25.1
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