linux-dev/net/wireless, branch master

wifi: cfg80211: Fix bitrates overflow issue

2022-10-21T10:36:35Z

When invoking function cfg80211_calculate_bitrate_eht about (320 MHz, EHT-MCS 13, EHT-NSS 2, EHT-GI 0), which means the parameters as flags: 0x80, bw: 7, mcs: 13, eht_gi: 0, nss: 2, this formula (result * rate->nss) will overflow and causes the returned bitrate to be 3959 when it should be 57646. Here is the explanation: u64 tmp; u32 result; … /* tmp = result = 4 * rates_996[0] * = 4 * 480388888 = 0x72889c60 */ tmp = result; /* tmp = 0x72889c60 * 6144 = 0xabccea90000 */ tmp *= SCALE; /* tmp = 0xabccea90000 / mcs_divisors[13] * = 0xabccea90000 / 5120 = 0x8970bba6 */ do_div(tmp, mcs_divisors[rate->mcs]); /* result = 0x8970bba6 */ result = tmp; /* normally (result * rate->nss) = 0x8970bba6 * 2 = 0x112e1774c, * but since result is u32, (result * rate->nss) = 0x12e1774c, * overflow happens and it loses the highest bit. * Then result = 0x12e1774c / 8 = 39595753, */ result = (result * rate->nss) / 8; Signed-off-by: Paul Zhang Signed-off-by: Johannes Berg

wifi: cfg80211: fix memory leak in query_regdb_file()

2022-10-21T10:35:57Z

In the function query_regdb_file() the alpha2 parameter is duplicated using kmemdup() and subsequently freed in regdb_fw_cb(). However, request_firmware_nowait() can fail without calling regdb_fw_cb() and thus leak memory. Fixes: 007f6c5e6eb4 ("cfg80211: support loading regulatory database as firmware file") Signed-off-by: Arend van Spriel Signed-off-by: Johannes Berg

wifi: cfg80211: silence a sparse RCU warning

2022-10-21T10:34:46Z

All we're going to do with this pointer is assign it to another __rcu pointer, but sparse can't see that, so use rcu_access_pointer() to silence the warning here. Fixes: c90b93b5b782 ("wifi: cfg80211: update hidden BSSes to avoid WARN_ON") Signed-off-by: Johannes Berg

Merge branch 'cve-fixes-2022-10-13'

2022-10-13T09:59:56Z

Pull in the fixes for various scan parsing bugs found by Sönke Huster by fuzzing.

wifi: cfg80211: update hidden BSSes to avoid WARN_ON

2022-10-10T07:51:34Z

When updating beacon elements in a non-transmitted BSS, also update the hidden sub-entries to the same beacon elements, so that a future update through other paths won't trigger a WARN_ON(). The warning is triggered because the beacon elements in the hidden BSSes that are children of the BSS should always be the same as in the parent. Reported-by: Sönke Huster Tested-by: Sönke Huster Fixes: 0b8fb8235be8 ("cfg80211: Parsing of Multiple BSSID information in scanning") Signed-off-by: Johannes Berg

wifi: cfg80211: avoid nontransmitted BSS list corruption

2022-10-10T07:51:01Z

If a non-transmitted BSS shares enough information (both SSID and BSSID!) with another non-transmitted BSS of a different AP, then we can find and update it, and then try to add it to the non-transmitted BSS list. We do a search for it on the transmitted BSS, but if it's not there (but belongs to another transmitted BSS), the list gets corrupted. Since this is an erroneous situation, simply fail the list insertion in this case and free the non-transmitted BSS. This fixes CVE-2022-42721. Reported-by: Sönke Huster Tested-by: Sönke Huster Fixes: 0b8fb8235be8 ("cfg80211: Parsing of Multiple BSSID information in scanning") Signed-off-by: Johannes Berg

wifi: cfg80211: fix BSS refcounting bugs

2022-10-10T07:50:51Z

There are multiple refcounting bugs related to multi-BSSID: - In bss_ref_get(), if the BSS has a hidden_beacon_bss, then the bss pointer is overwritten before checking for the transmitted BSS, which is clearly wrong. Fix this by using the bss_from_pub() macro. - In cfg80211_bss_update() we copy the transmitted_bss pointer from tmp into new, but then if we release new, we'll unref it erroneously. We already set the pointer and ref it, but need to NULL it since it was copied from the tmp data. - In cfg80211_inform_single_bss_data(), if adding to the non- transmitted list fails, we unlink the BSS and yet still we return it, but this results in returning an entry without a reference. We shouldn't return it anyway if it was broken enough to not get added there. This fixes CVE-2022-42720. Reported-by: Sönke Huster Tested-by: Sönke Huster Fixes: a3584f56de1c ("cfg80211: Properly track transmitting and non-transmitting BSS") Signed-off-by: Johannes Berg

wifi: cfg80211: ensure length byte is present before access

2022-10-10T07:50:37Z

When iterating the elements here, ensure the length byte is present before checking it to see if the entire element will fit into the buffer. Longer term, we should rewrite this code using the type-safe element iteration macros that check all of this. Fixes: 0b8fb8235be8 ("cfg80211: Parsing of Multiple BSSID information in scanning") Reported-by: Soenke Huster Signed-off-by: Johannes Berg

wifi: cfg80211/mac80211: reject bad MBSSID elements

2022-10-10T07:50:15Z

Per spec, the maximum value for the MaxBSSID ('n') indicator is 8, and the minimum is 1 since a multiple BSSID set with just one BSSID doesn't make sense (the # of BSSIDs is limited by 2^n). Limit this in the parsing in both cfg80211 and mac80211, rejecting any elements with an invalid value. This fixes potentially bad shifts in the processing of these inside the cfg80211_gen_new_bssid() function later. I found this during the investigation of CVE-2022-41674 fixed by the previous patch. Fixes: 0b8fb8235be8 ("cfg80211: Parsing of Multiple BSSID information in scanning") Fixes: 78ac51f81532 ("mac80211: support multi-bssid") Reviewed-by: Kees Cook Signed-off-by: Johannes Berg

wifi: cfg80211: fix u8 overflow in cfg80211_update_notlisted_nontrans()

2022-10-10T07:49:52Z

In the copy code of the elements, we do the following calculation to reach the end of the MBSSID element: /* copy the IEs after MBSSID */ cpy_len = mbssid[1] + 2; This looks fine, however, cpy_len is a u8, the same as mbssid[1], so the addition of two can overflow. In this case the subsequent memcpy() will overflow the allocated buffer, since it copies 256 bytes too much due to the way the allocation and memcpy() sizes are calculated. Fix this by using size_t for the cpy_len variable. This fixes CVE-2022-41674. Reported-by: Soenke Huster Tested-by: Soenke Huster Fixes: 0b8fb8235be8 ("cfg80211: Parsing of Multiple BSSID information in scanning") Reviewed-by: Kees Cook Signed-off-by: Johannes Berg