[PATCH] mac80211: radiotap: Use BIT() instead of shifts

From: Kees Cook
Date: Fri Aug 06 2021 - 17:51:28 EST

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IEEE80211_RADIOTAP_EXT has a value of 31, which means if shift was ever
cast to 64-bit, the result would become sign-extended. As a matter of
robustness, just replace all the open-coded shifts with BIT().

Suggested-by: David Sterba <dsterba@xxxxxxx>
Link: https://lore.kernel.org/lkml/20210728092323.GW5047@xxxxxxxxxxxxx/
Cc: Johannes Berg <johannes@xxxxxxxxxxxxxxxx>
Cc: "David S. Miller" <davem@xxxxxxxxxxxxx>
Cc: Jakub Kicinski <kuba@xxxxxxxxxx>
Cc: linux-wireless@xxxxxxxxxxxxxxx
Cc: netdev@xxxxxxxxxxxxxxx
Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
---
net/mac80211/rx.c | 22 +++++++++++-----------
net/mac80211/status.c | 16 ++++++++--------
net/wireless/radiotap.c | 4 ++--
3 files changed, 21 insertions(+), 21 deletions(-)

diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index 2563473b5cf1..3eb7b03b23c6 100644
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -372,7 +372,7 @@ ieee80211_add_rx_radiotap_header(struct ieee80211_local *local,
ieee80211_calculate_rx_timestamp(local, status,
mpdulen, 0),
pos);
- rthdr->it_present |= cpu_to_le32(1 << IEEE80211_RADIOTAP_TSFT);
+ rthdr->it_present |= cpu_to_le32(BIT(IEEE80211_RADIOTAP_TSFT));
pos += 8;
}

@@ -396,7 +396,7 @@ ieee80211_add_rx_radiotap_header(struct ieee80211_local *local,
*pos = 0;
} else {
int shift = 0;
- rthdr->it_present |= cpu_to_le32(1 << IEEE80211_RADIOTAP_RATE);
+ rthdr->it_present |= cpu_to_le32(BIT(IEEE80211_RADIOTAP_RATE));
if (status->bw == RATE_INFO_BW_10)
shift = 1;
else if (status->bw == RATE_INFO_BW_5)
@@ -433,7 +433,7 @@ ieee80211_add_rx_radiotap_header(struct ieee80211_local *local,
!(status->flag & RX_FLAG_NO_SIGNAL_VAL)) {
*pos = status->signal;
rthdr->it_present |=
- cpu_to_le32(1 << IEEE80211_RADIOTAP_DBM_ANTSIGNAL);
+ cpu_to_le32(BIT(IEEE80211_RADIOTAP_DBM_ANTSIGNAL));
pos++;
}

@@ -459,7 +459,7 @@ ieee80211_add_rx_radiotap_header(struct ieee80211_local *local,
if (status->encoding == RX_ENC_HT) {
unsigned int stbc;

- rthdr->it_present |= cpu_to_le32(1 << IEEE80211_RADIOTAP_MCS);
+ rthdr->it_present |= cpu_to_le32(BIT(IEEE80211_RADIOTAP_MCS));
*pos++ = local->hw.radiotap_mcs_details;
*pos = 0;
if (status->enc_flags & RX_ENC_FLAG_SHORT_GI)
@@ -483,7 +483,7 @@ ieee80211_add_rx_radiotap_header(struct ieee80211_local *local,
while ((pos - (u8 *)rthdr) & 3)
pos++;
rthdr->it_present |=
- cpu_to_le32(1 << IEEE80211_RADIOTAP_AMPDU_STATUS);
+ cpu_to_le32(BIT(IEEE80211_RADIOTAP_AMPDU_STATUS));
put_unaligned_le32(status->ampdu_reference, pos);
pos += 4;
if (status->flag & RX_FLAG_AMPDU_LAST_KNOWN)
@@ -510,7 +510,7 @@ ieee80211_add_rx_radiotap_header(struct ieee80211_local *local,
if (status->encoding == RX_ENC_VHT) {
u16 known = local->hw.radiotap_vht_details;

- rthdr->it_present |= cpu_to_le32(1 << IEEE80211_RADIOTAP_VHT);
+ rthdr->it_present |= cpu_to_le32(BIT(IEEE80211_RADIOTAP_VHT));
put_unaligned_le16(known, pos);
pos += 2;
/* flags */
@@ -554,7 +554,7 @@ ieee80211_add_rx_radiotap_header(struct ieee80211_local *local,
u8 flags = IEEE80211_RADIOTAP_TIMESTAMP_FLAG_32BIT;

rthdr->it_present |=
- cpu_to_le32(1 << IEEE80211_RADIOTAP_TIMESTAMP);
+ cpu_to_le32(BIT(IEEE80211_RADIOTAP_TIMESTAMP));

/* ensure 8 byte alignment */
while ((pos - (u8 *)rthdr) & 7)
@@ -642,7 +642,7 @@ ieee80211_add_rx_radiotap_header(struct ieee80211_local *local,
/* ensure 2 byte alignment */
while ((pos - (u8 *)rthdr) & 1)
pos++;
- rthdr->it_present |= cpu_to_le32(1 << IEEE80211_RADIOTAP_HE);
+ rthdr->it_present |= cpu_to_le32(BIT(IEEE80211_RADIOTAP_HE));
memcpy(pos, &he, sizeof(he));
pos += sizeof(he);
}
@@ -652,14 +652,14 @@ ieee80211_add_rx_radiotap_header(struct ieee80211_local *local,
/* ensure 2 byte alignment */
while ((pos - (u8 *)rthdr) & 1)
pos++;
- rthdr->it_present |= cpu_to_le32(1 << IEEE80211_RADIOTAP_HE_MU);
+ rthdr->it_present |= cpu_to_le32(BIT(IEEE80211_RADIOTAP_HE_MU));
memcpy(pos, &he_mu, sizeof(he_mu));
pos += sizeof(he_mu);
}

if (status->flag & RX_FLAG_NO_PSDU) {
rthdr->it_present |=
- cpu_to_le32(1 << IEEE80211_RADIOTAP_ZERO_LEN_PSDU);
+ cpu_to_le32(BIT(IEEE80211_RADIOTAP_ZERO_LEN_PSDU));
*pos++ = status->zero_length_psdu_type;
}

@@ -667,7 +667,7 @@ ieee80211_add_rx_radiotap_header(struct ieee80211_local *local,
/* ensure 2 byte alignment */
while ((pos - (u8 *)rthdr) & 1)
pos++;
- rthdr->it_present |= cpu_to_le32(1 << IEEE80211_RADIOTAP_LSIG);
+ rthdr->it_present |= cpu_to_le32(BIT(IEEE80211_RADIOTAP_LSIG));
memcpy(pos, &lsig, sizeof(lsig));
pos += sizeof(lsig);
}
diff --git a/net/mac80211/status.c b/net/mac80211/status.c
index bae321ff77f6..1f295e5721ef 100644
--- a/net/mac80211/status.c
+++ b/net/mac80211/status.c
@@ -305,8 +305,8 @@ ieee80211_add_tx_radiotap_header(struct ieee80211_local *local,
memset(rthdr, 0, rtap_len);
rthdr->it_len = cpu_to_le16(rtap_len);
rthdr->it_present =
- cpu_to_le32((1 << IEEE80211_RADIOTAP_TX_FLAGS) |
- (1 << IEEE80211_RADIOTAP_DATA_RETRIES));
+ cpu_to_le32(BIT(IEEE80211_RADIOTAP_TX_FLAGS) |
+ BIT(IEEE80211_RADIOTAP_DATA_RETRIES));
pos = (unsigned char *)(rthdr + 1);

/*
@@ -331,7 +331,7 @@ ieee80211_add_tx_radiotap_header(struct ieee80211_local *local,
sband->bitrates[info->status.rates[0].idx].bitrate;

if (legacy_rate) {
- rthdr->it_present |= cpu_to_le32(1 << IEEE80211_RADIOTAP_RATE);
+ rthdr->it_present |= cpu_to_le32(BIT(IEEE80211_RADIOTAP_RATE));
*pos = DIV_ROUND_UP(legacy_rate, 5 * (1 << shift));
/* padding for tx flags */
pos += 2;
@@ -358,7 +358,7 @@ ieee80211_add_tx_radiotap_header(struct ieee80211_local *local,

if (status && status->rate &&
(status->rate->flags & RATE_INFO_FLAGS_MCS)) {
- rthdr->it_present |= cpu_to_le32(1 << IEEE80211_RADIOTAP_MCS);
+ rthdr->it_present |= cpu_to_le32(BIT(IEEE80211_RADIOTAP_MCS));
pos[0] = IEEE80211_RADIOTAP_MCS_HAVE_MCS |
IEEE80211_RADIOTAP_MCS_HAVE_GI |
IEEE80211_RADIOTAP_MCS_HAVE_BW;
@@ -374,7 +374,7 @@ ieee80211_add_tx_radiotap_header(struct ieee80211_local *local,
(IEEE80211_RADIOTAP_VHT_KNOWN_GI |
IEEE80211_RADIOTAP_VHT_KNOWN_BANDWIDTH);

- rthdr->it_present |= cpu_to_le32(1 << IEEE80211_RADIOTAP_VHT);
+ rthdr->it_present |= cpu_to_le32(BIT(IEEE80211_RADIOTAP_VHT));

/* required alignment from rthdr */
pos = (u8 *)rthdr + ALIGN(pos - (u8 *)rthdr, 2);
@@ -419,7 +419,7 @@ ieee80211_add_tx_radiotap_header(struct ieee80211_local *local,
(status->rate->flags & RATE_INFO_FLAGS_HE_MCS)) {
struct ieee80211_radiotap_he *he;

- rthdr->it_present |= cpu_to_le32(1 << IEEE80211_RADIOTAP_HE);
+ rthdr->it_present |= cpu_to_le32(BIT(IEEE80211_RADIOTAP_HE));

/* required alignment from rthdr */
pos = (u8 *)rthdr + ALIGN(pos - (u8 *)rthdr, 2);
@@ -495,7 +495,7 @@ ieee80211_add_tx_radiotap_header(struct ieee80211_local *local,
/* IEEE80211_RADIOTAP_MCS
* IEEE80211_RADIOTAP_VHT */
if (info->status.rates[0].flags & IEEE80211_TX_RC_MCS) {
- rthdr->it_present |= cpu_to_le32(1 << IEEE80211_RADIOTAP_MCS);
+ rthdr->it_present |= cpu_to_le32(BIT(IEEE80211_RADIOTAP_MCS));
pos[0] = IEEE80211_RADIOTAP_MCS_HAVE_MCS |
IEEE80211_RADIOTAP_MCS_HAVE_GI |
IEEE80211_RADIOTAP_MCS_HAVE_BW;
@@ -512,7 +512,7 @@ ieee80211_add_tx_radiotap_header(struct ieee80211_local *local,
(IEEE80211_RADIOTAP_VHT_KNOWN_GI |
IEEE80211_RADIOTAP_VHT_KNOWN_BANDWIDTH);

- rthdr->it_present |= cpu_to_le32(1 << IEEE80211_RADIOTAP_VHT);
+ rthdr->it_present |= cpu_to_le32(BIT(IEEE80211_RADIOTAP_VHT));

/* required alignment from rthdr */
pos = (u8 *)rthdr + ALIGN(pos - (u8 *)rthdr, 2);
diff --git a/net/wireless/radiotap.c b/net/wireless/radiotap.c
index 36f1b59a78bf..8099c9564a59 100644
--- a/net/wireless/radiotap.c
+++ b/net/wireless/radiotap.c
@@ -125,13 +125,13 @@ int ieee80211_radiotap_iterator_init(

/* find payload start allowing for extended bitmap(s) */

- if (iterator->_bitmap_shifter & (1<<IEEE80211_RADIOTAP_EXT)) {
+ if (iterator->_bitmap_shifter & (BIT(IEEE80211_RADIOTAP_EXT))) {
if ((unsigned long)iterator->_arg -
(unsigned long)iterator->_rtheader + sizeof(uint32_t) >
(unsigned long)iterator->_max_length)
return -EINVAL;
while (get_unaligned_le32(iterator->_arg) &
- (1 << IEEE80211_RADIOTAP_EXT)) {
+ (BIT(IEEE80211_RADIOTAP_EXT))) {
iterator->_arg += sizeof(uint32_t);

/*
--
2.30.2

Next message: Michael Kelley: "RE: [PATCH] x86/hyper-v: guard against cpu mask changes in hyperv_flush_tlb_others()"
Previous message: Sebastian Reichel: "Re: [PATCH 2/2] power: supply: sbs-battery: add support for time_to_empty_now attribute"
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