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From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Cong Wang <cong.wang@bytedance.com>,
	syzbot+b2bf2652983d23734c5c@syzkaller.appspotmail.com,
	Steffen Klassert <steffen.klassert@secunet.com>,
	Herbert Xu <herbert@gondor.apana.org.au>,
	Sasha Levin <sashal@kernel.org>,
	netdev@vger.kernel.org
Subject: [PATCH AUTOSEL 5.4 01/17] af_key: relax availability checks for skb size calculation
Date: Tue,  2 Feb 2021 10:06:35 -0500	[thread overview]
Message-ID: <20210202150651.1864426-1-sashal@kernel.org> (raw)

From: Cong Wang <cong.wang@bytedance.com>

[ Upstream commit afbc293add6466f8f3f0c3d944d85f53709c170f ]

xfrm_probe_algs() probes kernel crypto modules and changes the
availability of struct xfrm_algo_desc. But there is a small window
where ealg->available and aalg->available get changed between
count_ah_combs()/count_esp_combs() and dump_ah_combs()/dump_esp_combs(),
in this case we may allocate a smaller skb but later put a larger
amount of data and trigger the panic in skb_put().

Fix this by relaxing the checks when counting the size, that is,
skipping the test of ->available. We may waste some memory for a few
of sizeof(struct sadb_comb), but it is still much better than a panic.

Reported-by: syzbot+b2bf2652983d23734c5c@syzkaller.appspotmail.com
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Cong Wang <cong.wang@bytedance.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 net/key/af_key.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/net/key/af_key.c b/net/key/af_key.c
index a915bc86620af..907d04a474597 100644
--- a/net/key/af_key.c
+++ b/net/key/af_key.c
@@ -2902,7 +2902,7 @@ static int count_ah_combs(const struct xfrm_tmpl *t)
 			break;
 		if (!aalg->pfkey_supported)
 			continue;
-		if (aalg_tmpl_set(t, aalg) && aalg->available)
+		if (aalg_tmpl_set(t, aalg))
 			sz += sizeof(struct sadb_comb);
 	}
 	return sz + sizeof(struct sadb_prop);
@@ -2920,7 +2920,7 @@ static int count_esp_combs(const struct xfrm_tmpl *t)
 		if (!ealg->pfkey_supported)
 			continue;
 
-		if (!(ealg_tmpl_set(t, ealg) && ealg->available))
+		if (!(ealg_tmpl_set(t, ealg)))
 			continue;
 
 		for (k = 1; ; k++) {
@@ -2931,7 +2931,7 @@ static int count_esp_combs(const struct xfrm_tmpl *t)
 			if (!aalg->pfkey_supported)
 				continue;
 
-			if (aalg_tmpl_set(t, aalg) && aalg->available)
+			if (aalg_tmpl_set(t, aalg))
 				sz += sizeof(struct sadb_comb);
 		}
 	}
-- 
2.27.0


             reply	other threads:[~2021-02-02 15:13 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-02-02 15:06 Sasha Levin [this message]
2021-02-02 15:06 ` [PATCH AUTOSEL 5.4 02/17] regulator: core: avoid regulator_resolve_supply() race condition Sasha Levin
2021-02-02 15:06 ` [PATCH AUTOSEL 5.4 03/17] mac80211: 160MHz with extended NSS BW in CSA Sasha Levin
2021-02-02 15:06 ` [PATCH AUTOSEL 5.4 04/17] ASoC: Intel: Skylake: Zero snd_ctl_elem_value Sasha Levin
2021-02-02 15:06 ` [PATCH AUTOSEL 5.4 05/17] chtls: Fix potential resource leak Sasha Levin
2021-02-02 15:06 ` [PATCH AUTOSEL 5.4 06/17] pNFS/NFSv4: Try to return invalid layout in pnfs_layout_process() Sasha Levin
2021-02-02 15:06 ` [PATCH AUTOSEL 5.4 07/17] ASoC: ak4458: correct reset polarity Sasha Levin
2021-02-02 15:06 ` [PATCH AUTOSEL 5.4 08/17] iwlwifi: mvm: skip power command when unbinding vif during CSA Sasha Levin
2021-02-02 15:06 ` [PATCH AUTOSEL 5.4 09/17] iwlwifi: mvm: take mutex for calling iwl_mvm_get_sync_time() Sasha Levin
2021-02-02 15:06 ` [PATCH AUTOSEL 5.4 10/17] iwlwifi: pcie: add a NULL check in iwl_pcie_txq_unmap Sasha Levin
2021-02-02 15:06 ` [PATCH AUTOSEL 5.4 11/17] iwlwifi: pcie: fix context info memory leak Sasha Levin
2021-02-02 15:06 ` [PATCH AUTOSEL 5.4 12/17] iwlwifi: mvm: invalidate IDs of internal stations at mvm start Sasha Levin
2021-02-02 15:06 ` [PATCH AUTOSEL 5.4 13/17] iwlwifi: mvm: guard against device removal in reprobe Sasha Levin
2021-02-02 15:06 ` [PATCH AUTOSEL 5.4 14/17] SUNRPC: Move simple_get_bytes and simple_get_netobj into private header Sasha Levin
2021-02-02 15:06 ` [PATCH AUTOSEL 5.4 15/17] SUNRPC: Handle 0 length opaque XDR object data properly Sasha Levin
2021-02-02 15:06 ` [PATCH AUTOSEL 5.4 16/17] i2c: mediatek: Move suspend and resume handling to NOIRQ phase Sasha Levin
2021-02-02 15:06 ` [PATCH AUTOSEL 5.4 17/17] blk-cgroup: Use cond_resched() when destroy blkgs Sasha Levin

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