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| author | Dmitry Antipov <dmantipov@yandex.ru> | 2024-05-17 18:33:32 +0300 |
|---|---|---|
| committer | Johannes Berg <johannes.berg@intel.com> | 2024-05-29 15:58:54 +0200 |
| commit | 92ecbb3ac6f3fe8ae9edf3226c76aa17b6800699 (patch) | |
| tree | db3521a256784cc0d58e90abfa54d9eddbb258dc /net | |
| parent | a26d8dc5227f449a54518a8b40733a54c6600a8b (diff) | |
| download | linux-stable-92ecbb3ac6f3fe8ae9edf3226c76aa17b6800699.tar.gz linux-stable-92ecbb3ac6f3fe8ae9edf3226c76aa17b6800699.tar.bz2 linux-stable-92ecbb3ac6f3fe8ae9edf3226c76aa17b6800699.zip | |
wifi: mac80211: fix UBSAN noise in ieee80211_prep_hw_scan()
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>
Diffstat (limited to 'net')
| -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 3da1c5c45035..8ecc4b710b0e 100644 --- a/net/mac80211/scan.c +++ b/net/mac80211/scan.c @@ -744,15 +744,21 @@ 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]); |