diff mbox series

[v3] rtlwifi: rtl8821ae: Fix global-out-of-bounds bug in _rtl8812ae_phy_set_txpower_limit()

Message ID 20221212023540.1540147-1-lizetao1@huawei.com (mailing list archive)
State Changes Requested
Delegated to: Kalle Valo
Headers show
Series [v3] rtlwifi: rtl8821ae: Fix global-out-of-bounds bug in _rtl8812ae_phy_set_txpower_limit() | expand

Commit Message

lizetao Dec. 12, 2022, 2:35 a.m. UTC
There is a global-out-of-bounds reported by KASAN:

  BUG: KASAN: global-out-of-bounds in
  _rtl8812ae_eq_n_byte.part.0+0x3d/0x84 [rtl8821ae]
  Read of size 1 at addr ffffffffa0773c43 by task NetworkManager/411

  CPU: 6 PID: 411 Comm: NetworkManager Tainted: G      D
  6.1.0-rc8+ #144 e15588508517267d37
  Hardware name: QEMU Standard PC (Q35 + ICH9, 2009),
  Call Trace:
   <TASK>
   ...
   kasan_report+0xbb/0x1c0
   _rtl8812ae_eq_n_byte.part.0+0x3d/0x84 [rtl8821ae]
   rtl8821ae_phy_bb_config.cold+0x346/0x641 [rtl8821ae]
   rtl8821ae_hw_init+0x1f5e/0x79b0 [rtl8821ae]
   ...
   </TASK>

The root cause of the problem is that the comparison order of
"prate_section" in _rtl8812ae_phy_set_txpower_limit() is wrong. The
_rtl8812ae_eq_n_byte() is used to compare the first n bytes of the two
strings from tail to head, which causes the problem. In the
_rtl8812ae_phy_set_txpower_limit(), it was originally intended to meet
this requirement by carefully designing the comparison order.
For example, "pregulation" and "pbandwidth" are compared in order of
length from small to large, first is 3 and last is 4. However, the
comparison order of "prate_section" dose not obey such order requirement,
therefore when "prate_section" is "HT", when comparing from tail to head,
it will lead to access out of bounds in _rtl8812ae_eq_n_byte(). As
mentioned above, the _rtl8812ae_eq_n_byte() has the same function as
strcmp(), so just strcmp() is enough.

Fix it by removing _rtl8812ae_eq_n_byte() and use strcmp() barely.
Although it can be fixed by adjusting the comparison order of
"prate_section", this may cause the value of "rate_section" to not be
from 0 to 5. In addition, commit "21e4b0726dc6" not only moved driver
from staging to regular tree, but also added setting txpower limit
function during the driver config phase, so the problem was introduced
by this commit.

Fixes: 21e4b0726dc6 ("rtlwifi: rtl8821ae: Move driver from staging to regular tree")
Signed-off-by: Li Zetao <lizetao1@huawei.com>
---
v1 -> v2: delete the third parameter of _rtl8812ae_eq_n_byte() and use
strcmp to replace loop comparison.
v2 -> v3: remove _rtl8812ae_eq_n_byte() and use strcmp() barely.

 .../wireless/realtek/rtlwifi/rtl8821ae/phy.c  | 52 +++++++------------
 1 file changed, 20 insertions(+), 32 deletions(-)

Comments

Ping-Ke Shih Dec. 12, 2022, 1:35 a.m. UTC | #1
> -----Original Message-----
> From: Li Zetao <lizetao1@huawei.com>
> Sent: Monday, December 12, 2022 10:36 AM
> To: Ping-Ke Shih <pkshih@realtek.com>
> Cc: Larry.Finger@lwfinger.net; davem@davemloft.net; edumazet@google.com; kuba@kernel.org;
> kvalo@kernel.org; linux-kernel@vger.kernel.org; linux-wireless@vger.kernel.org; linville@tuxdriver.com;
> lizetao1@huawei.com; netdev@vger.kernel.org; pabeni@redhat.com
> Subject: [PATCH v3] rtlwifi: rtl8821ae: Fix global-out-of-bounds bug in _rtl8812ae_phy_set_txpower_limit()
> 
> There is a global-out-of-bounds reported by KASAN:
> 
>   BUG: KASAN: global-out-of-bounds in
>   _rtl8812ae_eq_n_byte.part.0+0x3d/0x84 [rtl8821ae]
>   Read of size 1 at addr ffffffffa0773c43 by task NetworkManager/411
> 
>   CPU: 6 PID: 411 Comm: NetworkManager Tainted: G      D
>   6.1.0-rc8+ #144 e15588508517267d37
>   Hardware name: QEMU Standard PC (Q35 + ICH9, 2009),
>   Call Trace:
>    <TASK>
>    ...
>    kasan_report+0xbb/0x1c0
>    _rtl8812ae_eq_n_byte.part.0+0x3d/0x84 [rtl8821ae]
>    rtl8821ae_phy_bb_config.cold+0x346/0x641 [rtl8821ae]
>    rtl8821ae_hw_init+0x1f5e/0x79b0 [rtl8821ae]
>    ...
>    </TASK>
> 
> The root cause of the problem is that the comparison order of
> "prate_section" in _rtl8812ae_phy_set_txpower_limit() is wrong. The
> _rtl8812ae_eq_n_byte() is used to compare the first n bytes of the two
> strings from tail to head, which causes the problem. In the
> _rtl8812ae_phy_set_txpower_limit(), it was originally intended to meet
> this requirement by carefully designing the comparison order.
> For example, "pregulation" and "pbandwidth" are compared in order of
> length from small to large, first is 3 and last is 4. However, the
> comparison order of "prate_section" dose not obey such order requirement,
> therefore when "prate_section" is "HT", when comparing from tail to head,
> it will lead to access out of bounds in _rtl8812ae_eq_n_byte(). As
> mentioned above, the _rtl8812ae_eq_n_byte() has the same function as
> strcmp(), so just strcmp() is enough.
> 
> Fix it by removing _rtl8812ae_eq_n_byte() and use strcmp() barely.
> Although it can be fixed by adjusting the comparison order of
> "prate_section", this may cause the value of "rate_section" to not be
> from 0 to 5. In addition, commit "21e4b0726dc6" not only moved driver
> from staging to regular tree, but also added setting txpower limit
> function during the driver config phase, so the problem was introduced
> by this commit.
> 
> Fixes: 21e4b0726dc6 ("rtlwifi: rtl8821ae: Move driver from staging to regular tree")
> Signed-off-by: Li Zetao <lizetao1@huawei.com>

Thanks for your fix.

Acked-by: Ping-Ke Shih <pkshih@realtek.com>

> ---
> v1 -> v2: delete the third parameter of _rtl8812ae_eq_n_byte() and use
> strcmp to replace loop comparison.
> v2 -> v3: remove _rtl8812ae_eq_n_byte() and use strcmp() barely.
> 
>  .../wireless/realtek/rtlwifi/rtl8821ae/phy.c  | 52 +++++++------------
>  1 file changed, 20 insertions(+), 32 deletions(-)
> 

[...]
Ping-Ke Shih Dec. 12, 2022, 1:37 a.m. UTC | #2
> -----Original Message-----
> From: Ping-Ke Shih
> Sent: Monday, December 12, 2022 9:35 AM
> To: 'Li Zetao' <lizetao1@huawei.com>
> Cc: Larry.Finger@lwfinger.net; davem@davemloft.net; edumazet@google.com; kuba@kernel.org;
> kvalo@kernel.org; linux-kernel@vger.kernel.org; linux-wireless@vger.kernel.org; linville@tuxdriver.com;
> netdev@vger.kernel.org; pabeni@redhat.com
> Subject: RE: [PATCH v3] rtlwifi: rtl8821ae: Fix global-out-of-bounds bug in
> _rtl8812ae_phy_set_txpower_limit()
> 
> 
> 
> > -----Original Message-----
> > From: Li Zetao <lizetao1@huawei.com>
> > Sent: Monday, December 12, 2022 10:36 AM
> > To: Ping-Ke Shih <pkshih@realtek.com>
> > Cc: Larry.Finger@lwfinger.net; davem@davemloft.net; edumazet@google.com; kuba@kernel.org;
> > kvalo@kernel.org; linux-kernel@vger.kernel.org; linux-wireless@vger.kernel.org;
> linville@tuxdriver.com;
> > lizetao1@huawei.com; netdev@vger.kernel.org; pabeni@redhat.com
> > Subject: [PATCH v3] rtlwifi: rtl8821ae: Fix global-out-of-bounds bug in
> _rtl8812ae_phy_set_txpower_limit()

Oops. Subject prefix should be "wifi: rtlwifi: ...".

If it isn't hard to you, please fix it, and add my acked-by along with v4.

> >
> > There is a global-out-of-bounds reported by KASAN:
> >
> >   BUG: KASAN: global-out-of-bounds in
> >   _rtl8812ae_eq_n_byte.part.0+0x3d/0x84 [rtl8821ae]
> >   Read of size 1 at addr ffffffffa0773c43 by task NetworkManager/411
> >
> >   CPU: 6 PID: 411 Comm: NetworkManager Tainted: G      D
> >   6.1.0-rc8+ #144 e15588508517267d37
> >   Hardware name: QEMU Standard PC (Q35 + ICH9, 2009),
> >   Call Trace:
> >    <TASK>
> >    ...
> >    kasan_report+0xbb/0x1c0
> >    _rtl8812ae_eq_n_byte.part.0+0x3d/0x84 [rtl8821ae]
> >    rtl8821ae_phy_bb_config.cold+0x346/0x641 [rtl8821ae]
> >    rtl8821ae_hw_init+0x1f5e/0x79b0 [rtl8821ae]
> >    ...
> >    </TASK>
> >
> > The root cause of the problem is that the comparison order of
> > "prate_section" in _rtl8812ae_phy_set_txpower_limit() is wrong. The
> > _rtl8812ae_eq_n_byte() is used to compare the first n bytes of the two
> > strings from tail to head, which causes the problem. In the
> > _rtl8812ae_phy_set_txpower_limit(), it was originally intended to meet
> > this requirement by carefully designing the comparison order.
> > For example, "pregulation" and "pbandwidth" are compared in order of
> > length from small to large, first is 3 and last is 4. However, the
> > comparison order of "prate_section" dose not obey such order requirement,
> > therefore when "prate_section" is "HT", when comparing from tail to head,
> > it will lead to access out of bounds in _rtl8812ae_eq_n_byte(). As
> > mentioned above, the _rtl8812ae_eq_n_byte() has the same function as
> > strcmp(), so just strcmp() is enough.
> >
> > Fix it by removing _rtl8812ae_eq_n_byte() and use strcmp() barely.
> > Although it can be fixed by adjusting the comparison order of
> > "prate_section", this may cause the value of "rate_section" to not be
> > from 0 to 5. In addition, commit "21e4b0726dc6" not only moved driver
> > from staging to regular tree, but also added setting txpower limit
> > function during the driver config phase, so the problem was introduced
> > by this commit.
> >
> > Fixes: 21e4b0726dc6 ("rtlwifi: rtl8821ae: Move driver from staging to regular tree")
> > Signed-off-by: Li Zetao <lizetao1@huawei.com>
> 
> Thanks for your fix.
> 
> Acked-by: Ping-Ke Shih <pkshih@realtek.com>
> 
> > ---
> > v1 -> v2: delete the third parameter of _rtl8812ae_eq_n_byte() and use
> > strcmp to replace loop comparison.
> > v2 -> v3: remove _rtl8812ae_eq_n_byte() and use strcmp() barely.
> >
> >  .../wireless/realtek/rtlwifi/rtl8821ae/phy.c  | 52 +++++++------------
> >  1 file changed, 20 insertions(+), 32 deletions(-)
> >
> 
> [...]
diff mbox series

Patch

diff --git a/drivers/net/wireless/realtek/rtlwifi/rtl8821ae/phy.c b/drivers/net/wireless/realtek/rtlwifi/rtl8821ae/phy.c
index a29321e2fa72..5323ead30db0 100644
--- a/drivers/net/wireless/realtek/rtlwifi/rtl8821ae/phy.c
+++ b/drivers/net/wireless/realtek/rtlwifi/rtl8821ae/phy.c
@@ -1598,18 +1598,6 @@  static bool _rtl8812ae_get_integer_from_string(const char *str, u8 *pint)
 	return true;
 }
 
-static bool _rtl8812ae_eq_n_byte(const char *str1, const char *str2, u32 num)
-{
-	if (num == 0)
-		return false;
-	while (num > 0) {
-		num--;
-		if (str1[num] != str2[num])
-			return false;
-	}
-	return true;
-}
-
 static s8 _rtl8812ae_phy_get_chnl_idx_of_txpwr_lmt(struct ieee80211_hw *hw,
 					      u8 band, u8 channel)
 {
@@ -1659,42 +1647,42 @@  static void _rtl8812ae_phy_set_txpower_limit(struct ieee80211_hw *hw,
 	power_limit = power_limit > MAX_POWER_INDEX ?
 		      MAX_POWER_INDEX : power_limit;
 
-	if (_rtl8812ae_eq_n_byte(pregulation, "FCC", 3))
+	if (strcmp(pregulation, "FCC") == 0)
 		regulation = 0;
-	else if (_rtl8812ae_eq_n_byte(pregulation, "MKK", 3))
+	else if (strcmp(pregulation, "MKK") == 0)
 		regulation = 1;
-	else if (_rtl8812ae_eq_n_byte(pregulation, "ETSI", 4))
+	else if (strcmp(pregulation, "ETSI") == 0)
 		regulation = 2;
-	else if (_rtl8812ae_eq_n_byte(pregulation, "WW13", 4))
+	else if (strcmp(pregulation, "WW13") == 0)
 		regulation = 3;
 
-	if (_rtl8812ae_eq_n_byte(prate_section, "CCK", 3))
+	if (strcmp(prate_section, "CCK") == 0)
 		rate_section = 0;
-	else if (_rtl8812ae_eq_n_byte(prate_section, "OFDM", 4))
+	else if (strcmp(prate_section, "OFDM") == 0)
 		rate_section = 1;
-	else if (_rtl8812ae_eq_n_byte(prate_section, "HT", 2) &&
-		 _rtl8812ae_eq_n_byte(prf_path, "1T", 2))
+	else if (strcmp(prate_section, "HT") == 0 &&
+		 strcmp(prf_path, "1T") == 0)
 		rate_section = 2;
-	else if (_rtl8812ae_eq_n_byte(prate_section, "HT", 2) &&
-		 _rtl8812ae_eq_n_byte(prf_path, "2T", 2))
+	else if (strcmp(prate_section, "HT") == 0 &&
+		 strcmp(prf_path, "2T") == 0)
 		rate_section = 3;
-	else if (_rtl8812ae_eq_n_byte(prate_section, "VHT", 3) &&
-		 _rtl8812ae_eq_n_byte(prf_path, "1T", 2))
+	else if (strcmp(prate_section, "VHT") == 0 &&
+		 strcmp(prf_path, "1T") == 0)
 		rate_section = 4;
-	else if (_rtl8812ae_eq_n_byte(prate_section, "VHT", 3) &&
-		 _rtl8812ae_eq_n_byte(prf_path, "2T", 2))
+	else if (strcmp(prate_section, "VHT") == 0 &&
+		 strcmp(prf_path, "2T") == 0)
 		rate_section = 5;
 
-	if (_rtl8812ae_eq_n_byte(pbandwidth, "20M", 3))
+	if (strcmp(pbandwidth, "20M") == 0)
 		bandwidth = 0;
-	else if (_rtl8812ae_eq_n_byte(pbandwidth, "40M", 3))
+	else if (strcmp(pbandwidth, "40M") == 0)
 		bandwidth = 1;
-	else if (_rtl8812ae_eq_n_byte(pbandwidth, "80M", 3))
+	else if (strcmp(pbandwidth, "80M") == 0)
 		bandwidth = 2;
-	else if (_rtl8812ae_eq_n_byte(pbandwidth, "160M", 4))
+	else if (strcmp(pbandwidth, "160M") == 0)
 		bandwidth = 3;
 
-	if (_rtl8812ae_eq_n_byte(pband, "2.4G", 4)) {
+	if (strcmp(pband, "2.4G") == 0) {
 		ret = _rtl8812ae_phy_get_chnl_idx_of_txpwr_lmt(hw,
 							       BAND_ON_2_4G,
 							       channel);
@@ -1718,7 +1706,7 @@  static void _rtl8812ae_phy_set_txpower_limit(struct ieee80211_hw *hw,
 			regulation, bandwidth, rate_section, channel_index,
 			rtlphy->txpwr_limit_2_4g[regulation][bandwidth]
 				[rate_section][channel_index][RF90_PATH_A]);
-	} else if (_rtl8812ae_eq_n_byte(pband, "5G", 2)) {
+	} else if (strcmp(pband, "5G") == 0) {
 		ret = _rtl8812ae_phy_get_chnl_idx_of_txpwr_lmt(hw,
 							       BAND_ON_5G,
 							       channel);