diff options
| author | Dmitry Antipov <dmantipov@yandex.ru> | 2024-05-17 18:33:32 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2024-07-27 10:33:41 +0200 |
| commit | cd3212a9e0209dff7eda30f01ab8590f5e8d92fb (patch) | |
| tree | beb302a69ade7efd75093d7abf2f35280d43fa86 | |
| parent | 46487275e810d1e7c99f36af9fdfae0909c4e200 (diff) | |
wifi: mac80211: fix UBSAN noise in ieee80211_prep_hw_scan()
[ Upstream commit 92ecbb3ac6f3fe8ae9edf3226c76aa17b6800699 ]
When testing the previous patch with CONFIG_UBSAN_BOUNDS, I've
noticed the following:
UBSAN: array-index-out-of-bounds in net/mac80211/scan.c:372:4
index 0 is out of range for type 'struct ieee80211_channel *[]'
CPU: 0 PID: 1435 Comm: wpa_supplicant Not tainted 6.9.0+ #1
Hardware name: LENOVO 20UN005QRT/20UN005QRT <...BIOS details...>
Call Trace:
<TASK>
dump_stack_lvl+0x2d/0x90
__ubsan_handle_out_of_bounds+0xe7/0x140
? timerqueue_add+0x98/0xb0
ieee80211_prep_hw_scan+0x2db/0x480 [mac80211]
? __kmalloc+0xe1/0x470
__ieee80211_start_scan+0x541/0x760 [mac80211]
rdev_scan+0x1f/0xe0 [cfg80211]
nl80211_trigger_scan+0x9b6/0xae0 [cfg80211]
...<the rest is not too useful...>
Since '__ieee80211_start_scan()' leaves 'hw_scan_req->req.n_channels'
uninitialized, actual boundaries of 'hw_scan_req->req.channels' can't
be checked in 'ieee80211_prep_hw_scan()'. Although an initialization
of 'hw_scan_req->req.n_channels' introduces some confusion around
allocated vs. used VLA members, this shouldn't be a problem since
everything is correctly adjusted soon in 'ieee80211_prep_hw_scan()'.
Cleanup 'kmalloc()' math in '__ieee80211_start_scan()' by using the
convenient 'struct_size()' as well.
Signed-off-by: Dmitry Antipov <dmantipov@yandex.ru>
Link: https://msgid.link/20240517153332.18271-2-dmantipov@yandex.ru
[improve (imho) indentation a bit]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -rw-r--r-- | net/mac80211/scan.c | 14 |
1 files changed, 10 insertions, 4 deletions
diff --git a/net/mac80211/scan.c b/net/mac80211/scan.c index e3d8be4feea5..76fb858dc890 100644 --- a/net/mac80211/scan.c +++ b/net/mac80211/scan.c @@ -652,15 +652,21 @@ static int __ieee80211_start_scan(struct ieee80211_sub_if_data *sdata, local->hw_scan_ies_bufsize *= n_bands; } - local->hw_scan_req = kmalloc( - sizeof(*local->hw_scan_req) + - req->n_channels * sizeof(req->channels[0]) + - local->hw_scan_ies_bufsize, GFP_KERNEL); + local->hw_scan_req = kmalloc(struct_size(local->hw_scan_req, + req.channels, + req->n_channels) + + local->hw_scan_ies_bufsize, + GFP_KERNEL); if (!local->hw_scan_req) return -ENOMEM; local->hw_scan_req->req.ssids = req->ssids; local->hw_scan_req->req.n_ssids = req->n_ssids; + /* None of the channels are actually set + * up but let UBSAN know the boundaries. + */ + local->hw_scan_req->req.n_channels = req->n_channels; + ies = (u8 *)local->hw_scan_req + sizeof(*local->hw_scan_req) + req->n_channels * sizeof(req->channels[0]); |