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| author | Cong Wang <cong.wang@bytedance.com> | 2020-12-26 16:50:20 -0800 |
|---|---|---|
| committer | Steffen Klassert <steffen.klassert@secunet.com> | 2021-01-04 10:05:50 +0100 |
| commit | afbc293add6466f8f3f0c3d944d85f53709c170f (patch) | |
| tree | 97288782f050eb5a58aa1ecb6149a23bef333dff /net/key | |
| parent | 9f8550e4bd9d78a8436c2061ad2530215f875376 (diff) | |
| download | linux-stable-afbc293add6466f8f3f0c3d944d85f53709c170f.tar.gz linux-stable-afbc293add6466f8f3f0c3d944d85f53709c170f.tar.bz2 linux-stable-afbc293add6466f8f3f0c3d944d85f53709c170f.zip | |
af_key: relax availability checks for skb size calculation
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>
Diffstat (limited to 'net/key')
| -rw-r--r-- | net/key/af_key.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/net/key/af_key.c b/net/key/af_key.c index c12dbc51ef5f..ef9b4ac03e7b 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); } } |