[REGRESSION] Patch broke WPA auth: Re: [PATCH v2] wifi: cfg80211: Fix use after free for wext
From: Hector Martin <hidden>
Date: 2023-03-11 09:56:25
Also in:
asahi, lkml, regressions, stable
Hi, This broke WPA auth entirely on brcmfmac (in offload mode) and probably others, including on stable 6.2.3 and 6.3-rc1 (tested with iwd). Please revert or fix. Notes below. Reported-by: Ilya <redacted> Reported-by: Janne Grunau <j@jannau.net> #regzbot introduced: 015b8cc5e7c4d7 #regzbot monitor: https://lore.kernel.org/linux-wireless/20230124141856.356646-1-alexander@wetzel-home.de/ (local) On 24/01/2023 23.18, Alexander Wetzel wrote:
quoted hunk ↗ jump to hunk
Key information in wext.connect is not reset on (re)connect and can hold data from a previous connection. Reset key data to avoid that drivers or mac80211 incorrectly detect a WEP connection request and access the freed or already reused memory. Additionally optimize cfg80211_sme_connect() and avoid an useless schedule of conn_work. Fixes: fffd0934b939 ("cfg80211: rework key operation") Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/c80f04d2-8159-a02a-9287-26e5ec838826@wetzel-home.de (local) Signed-off-by: Alexander Wetzel <redacted> --- V2 changes: - updated comment - reset more key data --- net/wireless/sme.c | 31 ++++++++++++++++++++++++++----- 1 file changed, 26 insertions(+), 5 deletions(-)diff --git a/net/wireless/sme.c b/net/wireless/sme.c index 123248b2c0be..0cc841c0c59b 100644 --- a/net/wireless/sme.c +++ b/net/wireless/sme.c
[snip]
quoted hunk ↗ jump to hunk
@@ -1464,6 +1476,15 @@ int cfg80211_connect(struct cfg80211_registered_device *rdev,
This if branch only fires if the connection is WEP.
} else {
if (WARN_ON(connkeys))
return -EINVAL;
+
+ /* connect can point to wdev->wext.connect which
+ * can hold key data from a previous connection
+ */
+ connect->key = NULL;
+ connect->key_len = 0;
+ connect->key_idx = 0;And these are indeed only used by WEP.
+ connect->crypto.cipher_group = 0; + connect->crypto.n_ciphers_pairwise = 0;
But here you're killing the info that is used for *other* auth modes too if !WEP, breaking WPA and everything else.
} wdev->connect_keys = connkeys;
- Hector