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authorHarshit Mogalapalli <harshit.m.mogalapalli@oracle.com>2022-06-20 09:28:24 -0700
committerJiri Kosina <jkosina@suse.cz>2022-07-21 11:54:40 +0200
commit62ac2473553a00229e67bdf3cb023b62cf7f5a9a (patch)
tree0e190aa9d5101a22cef662e9964b9492b686d4a3 /drivers/hid
parent54eed5c7b938dc4ef6b14d4ee048bbdafdbce352 (diff)
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HID: mcp2221: prevent a buffer overflow in mcp_smbus_write()
Smatch Warning: drivers/hid/hid-mcp2221.c:388 mcp_smbus_write() error: __memcpy() '&mcp->txbuf[5]' too small (59 vs 255) drivers/hid/hid-mcp2221.c:388 mcp_smbus_write() error: __memcpy() 'buf' too small (34 vs 255) The 'len' variable can take a value between 0-255 as it can come from data->block[0] and it is user data. So add an bound check to prevent a buffer overflow in memcpy(). Fixes: 67a95c21463d ("HID: mcp2221: add usb to i2c-smbus host bridge") Signed-off-by: Harshit Mogalapalli <harshit.m.mogalapalli@oracle.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Diffstat (limited to 'drivers/hid')
-rw-r--r--drivers/hid/hid-mcp2221.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/drivers/hid/hid-mcp2221.c b/drivers/hid/hid-mcp2221.c
index 4211b9839209..de52e9f7bb8c 100644
--- a/drivers/hid/hid-mcp2221.c
+++ b/drivers/hid/hid-mcp2221.c
@@ -385,6 +385,9 @@ static int mcp_smbus_write(struct mcp2221 *mcp, u16 addr,
data_len = 7;
break;
default:
+ if (len > I2C_SMBUS_BLOCK_MAX)
+ return -EINVAL;
+
memcpy(&mcp->txbuf[5], buf, len);
data_len = len + 5;
}