[PATCH AUTOSEL 6.11 076/244] wifi: rtw89: avoid reading out of bounds when loading TX power FW elements

Sasha Levin
2024-09-25T11:39:42Z

From: Zong-Zhe Yang <kevin_yang@realtek.com>

[ Upstream commit ed2e4bb17a4884cf29c3347353d8aabb7265b46c ]

Because the loop-expression will do one more time before getting false from
cond-expression, the original code copied one more entry size beyond valid
region.

Fix it by moving the entry copy to loop-body.

Signed-off-by: Zong-Zhe Yang <kevin_yang@realtek.com>
Signed-off-by: Ping-Ke Shih <pkshih@realtek.com>
Link: https://patch.msgid.link/20240902015803.20420-1-pkshih@realtek.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/net/wireless/realtek/rtw89/core.h | 18 ++++++++++++------
1 file changed, 12 insertions(+), 6 deletions(-)

diff --git a/drivers/net/wireless/realtek/rtw89/core.h b/drivers/net/wireless/realtek/rtw89/core.h
index 11fa003a9788c..a7ec7eed83812 100644
--- a/drivers/net/wireless/realtek/rtw89/core.h
+++ b/drivers/net/wireless/realtek/rtw89/core.h
@@ -3909,16 +3909,22 @@ struct rtw89_txpwr_conf {
const void *data;
};

+static inline bool rtw89_txpwr_entcpy(void *entry, const void *cursor, u8 size,
+ const struct rtw89_txpwr_conf *conf)
+{
+ u8 valid_size = min(size, conf->ent_sz);
+
+ memcpy(entry, cursor, valid_size);
+ return true;
+}
+
#define rtw89_txpwr_conf_valid(conf) (!!(conf)->data)

#define rtw89_for_each_in_txpwr_conf(entry, cursor, conf) \
- for (typecheck(const void *, cursor), (cursor) = (conf)->data, \
- memcpy(&(entry), cursor, \
- min_t(u8, sizeof(entry), (conf)->ent_sz)); \
+ for (typecheck(const void *, cursor), (cursor) = (conf)->data; \
(cursor) < (conf)->data + (conf)->num_ents * (conf)->ent_sz; \
- (cursor) += (conf)->ent_sz, \
- memcpy(&(entry), cursor, \
- min_t(u8, sizeof(entry), (conf)->ent_sz)))
+ (cursor) += (conf)->ent_sz) \
+ if (rtw89_txpwr_entcpy(&(entry), cursor, sizeof(entry), conf))

struct rtw89_txpwr_byrate_data {
struct rtw89_txpwr_conf conf;
--
2.43.0