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author | Harshit Mogalapalli <harshit.m.mogalapalli@oracle.com> | 2022-06-08 05:26:09 -0700 |
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committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-08-25 11:15:14 +0200 |
commit | 3af7d60e9a6c17d6d41c4341f8020511887d372d (patch) | |
tree | d8a1d3ee8a168cae76dfc49d11151d81b02399a9 | |
parent | d10855876a6f47add6ff621cef25cc0171dac162 (diff) | |
download | linux-stable-3af7d60e9a6c17d6d41c4341f8020511887d372d.tar.gz linux-stable-3af7d60e9a6c17d6d41c4341f8020511887d372d.tar.bz2 linux-stable-3af7d60e9a6c17d6d41c4341f8020511887d372d.zip |
HID: cp2112: prevent a buffer overflow in cp2112_xfer()
[ Upstream commit 381583845d19cb4bd21c8193449385f3fefa9caf ]
Smatch warnings:
drivers/hid/hid-cp2112.c:793 cp2112_xfer() error: __memcpy()
'data->block[1]' too small (33 vs 255)
drivers/hid/hid-cp2112.c:793 cp2112_xfer() error: __memcpy() 'buf' too
small (64 vs 255)
The 'read_length' variable is provided by 'data->block[0]' which comes
from user and it(read_length) can take a value between 0-255. Add an
upper bound to 'read_length' variable to prevent a buffer overflow in
memcpy().
Fixes: 542134c0375b ("HID: cp2112: Fix I2C_BLOCK_DATA transactions")
Signed-off-by: Harshit Mogalapalli <harshit.m.mogalapalli@oracle.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Sasha Levin <sashal@kernel.org>
-rw-r--r-- | drivers/hid/hid-cp2112.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/drivers/hid/hid-cp2112.c b/drivers/hid/hid-cp2112.c index 6f65f5257236..637a7ce281c6 100644 --- a/drivers/hid/hid-cp2112.c +++ b/drivers/hid/hid-cp2112.c @@ -794,6 +794,11 @@ static int cp2112_xfer(struct i2c_adapter *adap, u16 addr, data->word = le16_to_cpup((__le16 *)buf); break; case I2C_SMBUS_I2C_BLOCK_DATA: + if (read_length > I2C_SMBUS_BLOCK_MAX) { + ret = -EINVAL; + goto power_normal; + } + memcpy(data->block + 1, buf, read_length); break; case I2C_SMBUS_BLOCK_DATA: |