[SRU][Jammy][PATCH 2/2] ASoC: cs35l41: Fix an out-of-bounds access in otp_packed_element_t

[Hui Wang]

BugLink: https://bugs.launchpad.net/bugs/1996121

The CS35L41_NUM_OTP_ELEM is 100, but only 99 entries are defined in
the array otp_map_1/2[CS35L41_NUM_OTP_ELEM], this will trigger UBSAN
to report a shift-out-of-bounds warning in the cs35l41_otp_unpack()
since the last entry in the array will result in GENMASK(-1, 0).

UBSAN reports this problem:
 UBSAN: shift-out-of-bounds in /home/hwang4/build/jammy/jammy/sound/soc/codecs/cs35l41-lib.c:836:8
 shift exponent 64 is too large for 64-bit type 'long unsigned int'
 CPU: 10 PID: 595 Comm: systemd-udevd Not tainted 5.15.0-23-generic #23
 Hardware name: LENOVO \x02MFG_IN_GO/\x02MFG_IN_GO, BIOS N3GET19W (1.00 ) 03/11/2022
 Call Trace:
  <TASK>
  show_stack+0x52/0x58
  dump_stack_lvl+0x4a/0x5f
  dump_stack+0x10/0x12
  ubsan_epilogue+0x9/0x45
  __ubsan_handle_shift_out_of_bounds.cold+0x61/0xef
  ? regmap_unlock_mutex+0xe/0x10
  cs35l41_otp_unpack.cold+0x1c6/0x2b2 [snd_soc_cs35l41_lib]
  cs35l41_hda_probe+0x24f/0x33a [snd_hda_scodec_cs35l41]
  cs35l41_hda_i2c_probe+0x65/0x90 [snd_hda_scodec_cs35l41_i2c]
  ? cs35l41_hda_i2c_remove+0x20/0x20 [snd_hda_scodec_cs35l41_i2c]
  i2c_device_probe+0x252/0x2b0

Fixes: 6450ef559056 ("ASoC: cs35l41: CS35L41 Boosted Smart Amplifier")
Reviewed-by: Lucas Tanure <tanureal at opensource.cirrus.com>
Acked-by: Charles Keepax <ckeepax at opensource.cirrus.com>
Signed-off-by: Hui Wang <hui.wang at canonical.com>
Link: https://lore.kernel.org/r/20220328123535.50000-2-hui.wang@canonical.com
Signed-off-by: Mark Brown <broonie at kernel.org>
(cherry picked from commit 9f342904216f378e88008bb0ce1ae200a4b99fe8)
Signed-off-by: Hui Wang <hui.wang at canonical.com>
---
 include/sound/cs35l41.h        |  1 -
 sound/soc/codecs/cs35l41-lib.c | 14 +++++++-------
 2 files changed, 7 insertions(+), 8 deletions(-)

diff --git a/include/sound/cs35l41.h b/include/sound/cs35l41.h
index bf7f9a9aeba0..9341130257ea 100644
--- a/include/sound/cs35l41.h
+++ b/include/sound/cs35l41.h
@@ -536,7 +536,6 @@
 
 #define CS35L41_MAX_CACHE_REG		36
 #define CS35L41_OTP_SIZE_WORDS		32
-#define CS35L41_NUM_OTP_ELEM		100
 
 #define CS35L41_VALID_PDATA		0x80000000
 #define CS35L41_NUM_SUPPLIES            2
diff --git a/sound/soc/codecs/cs35l41-lib.c b/sound/soc/codecs/cs35l41-lib.c
index 810643be13a4..9aa2b8948c61 100644
--- a/sound/soc/codecs/cs35l41-lib.c
+++ b/sound/soc/codecs/cs35l41-lib.c
@@ -422,7 +422,7 @@ static bool cs35l41_volatile_reg(struct device *dev, unsigned int reg)
 	}
 }
 
-static const struct cs35l41_otp_packed_element_t otp_map_1[CS35L41_NUM_OTP_ELEM] = {
+static const struct cs35l41_otp_packed_element_t otp_map_1[] = {
 	/* addr         shift   size */
 	{ 0x00002030,	0,	4 }, /*TRIM_OSC_FREQ_TRIM*/
 	{ 0x00002030,	7,	1 }, /*TRIM_OSC_TRIM_DONE*/
@@ -525,7 +525,7 @@ static const struct cs35l41_otp_packed_element_t otp_map_1[CS35L41_NUM_OTP_ELEM]
 	{ 0x00017044,	0,	24 }, /*LOT_NUMBER*/
 };
 
-static const struct cs35l41_otp_packed_element_t otp_map_2[CS35L41_NUM_OTP_ELEM] = {
+static const struct cs35l41_otp_packed_element_t otp_map_2[] = {
 	/* addr         shift   size */
 	{ 0x00002030,	0,	4 }, /*TRIM_OSC_FREQ_TRIM*/
 	{ 0x00002030,	7,	1 }, /*TRIM_OSC_TRIM_DONE*/
@@ -671,35 +671,35 @@ static const struct cs35l41_otp_map_element_t cs35l41_otp_map_map[] = {
 	{
 		.id = 0x01,
 		.map = otp_map_1,
-		.num_elements = CS35L41_NUM_OTP_ELEM,
+		.num_elements = ARRAY_SIZE(otp_map_1),
 		.bit_offset = 16,
 		.word_offset = 2,
 	},
 	{
 		.id = 0x02,
 		.map = otp_map_2,
-		.num_elements = CS35L41_NUM_OTP_ELEM,
+		.num_elements = ARRAY_SIZE(otp_map_2),
 		.bit_offset = 16,
 		.word_offset = 2,
 	},
 	{
 		.id = 0x03,
 		.map = otp_map_2,
-		.num_elements = CS35L41_NUM_OTP_ELEM,
+		.num_elements = ARRAY_SIZE(otp_map_2),
 		.bit_offset = 16,
 		.word_offset = 2,
 	},
 	{
 		.id = 0x06,
 		.map = otp_map_2,
-		.num_elements = CS35L41_NUM_OTP_ELEM,
+		.num_elements = ARRAY_SIZE(otp_map_2),
 		.bit_offset = 16,
 		.word_offset = 2,
 	},
 	{
 		.id = 0x08,
 		.map = otp_map_1,
-		.num_elements = CS35L41_NUM_OTP_ELEM,
+		.num_elements = ARRAY_SIZE(otp_map_1),
 		.bit_offset = 16,
 		.word_offset = 2,
 	},
-- 
2.34.1