Input: iforce - invert valid length check when fetching device IDs

stable inclusion
from stable-v5.10.156
commit 24cc679abbf31477d0cc6106ec83c2fbae6b3cdf
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I7MCG1

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=24cc679abbf31477d0cc6106ec83c2fbae6b3cdf

--------------------------------

commit b8ebf250 upstream.

syzbot is reporting uninitialized value at iforce_init_device() [1], for
commit 6ac0aec6 ("Input: iforce - allow callers supply data buffer
when fetching device IDs") is checking that valid length is shorter than
bytes to read. Since iforce_get_id_packet() stores valid length when
returning 0, the caller needs to check that valid length is longer than or
equals to bytes to read.
Reported-by: Nsyzbot <syzbot+4dd880c1184280378821@syzkaller.appspotmail.com>
Signed-off-by: NTetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Fixes: 6ac0aec6 ("Input: iforce - allow callers supply data buffer when fetching device IDs")
Link: https://lore.kernel.org/r/531fb432-7396-ad37-ecba-3e42e7f56d5c@I-love.SAKURA.ne.jp
Cc: stable@vger.kernel.org
Signed-off-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Nsanglipeng <sanglipeng1@jd.com>
(cherry picked from commit 4df4084c)

drivers/input/joystick/iforce/iforce-main.c

@@ -273,22 +273,22 @@ int iforce_init_device(struct device *parent, u16 bustype,
  * Get device info.
  */
 
-	if (!iforce_get_id_packet(iforce, 'M', buf, &len) || len < 3)
+	if (!iforce_get_id_packet(iforce, 'M', buf, &len) && len >= 3)
 		input_dev->id.vendor = get_unaligned_le16(buf + 1);
 	else
 		dev_warn(&iforce->dev->dev, "Device does not respond to id packet M\n");
 
-	if (!iforce_get_id_packet(iforce, 'P', buf, &len) || len < 3)
+	if (!iforce_get_id_packet(iforce, 'P', buf, &len) && len >= 3)
 		input_dev->id.product = get_unaligned_le16(buf + 1);
 	else
 		dev_warn(&iforce->dev->dev, "Device does not respond to id packet P\n");
 
-	if (!iforce_get_id_packet(iforce, 'B', buf, &len) || len < 3)
+	if (!iforce_get_id_packet(iforce, 'B', buf, &len) && len >= 3)
 		iforce->device_memory.end = get_unaligned_le16(buf + 1);
 	else
 		dev_warn(&iforce->dev->dev, "Device does not respond to id packet B\n");
 
-	if (!iforce_get_id_packet(iforce, 'N', buf, &len) || len < 2)
+	if (!iforce_get_id_packet(iforce, 'N', buf, &len) && len >= 2)
 		ff_effects = buf[1];
 	else
 		dev_warn(&iforce->dev->dev, "Device does not respond to id packet N\n");