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| author | Johan Hovold <johan@kernel.org> | 2026-05-22 16:22:18 +0200 |
|---|---|---|
| committer | Johan Hovold <johan@kernel.org> | 2026-05-23 09:07:36 +0200 |
| commit | 438061ed1ad85e6743e2dce826671772d81089ec (patch) | |
| tree | daaee33b20e214c31d701e365aa92820543ed011 /drivers/usb | |
| parent | 60df93d30f9bdd27db17c4d80ed80ef718d7226b (diff) | |
| download | linux-next-438061ed1ad85e6743e2dce826671772d81089ec.tar.gz linux-next-438061ed1ad85e6743e2dce826671772d81089ec.zip | |
USB: serial: safe_serial: fix memory corruption with small endpoint
Make sure that the bulk-out buffer size is at least eight bytes to avoid
user-controlled slab corruption in "safe" mode should a malicious device
report a smaller size.
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Cc: stable@vger.kernel.org
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Johan Hovold <johan@kernel.org>
Diffstat (limited to 'drivers/usb')
| -rw-r--r-- | drivers/usb/serial/safe_serial.c | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/drivers/usb/serial/safe_serial.c b/drivers/usb/serial/safe_serial.c index 238b54993446..d267a31dcccf 100644 --- a/drivers/usb/serial/safe_serial.c +++ b/drivers/usb/serial/safe_serial.c @@ -259,6 +259,7 @@ static int safe_prepare_write_buffer(struct usb_serial_port *port, static int safe_startup(struct usb_serial *serial) { struct usb_interface_descriptor *desc; + int bulk_out_size; if (serial->dev->descriptor.bDeviceClass != CDC_DEVICE_CLASS) return -ENODEV; @@ -279,6 +280,16 @@ static int safe_startup(struct usb_serial *serial) default: return -EINVAL; } + + /* + * The bulk-out buffer needs to be large enough for the two-byte + * trailer in safe mode, but assume anything smaller than eight bytes + * is broken. + */ + bulk_out_size = serial->port[0]->bulk_out_size; + if (bulk_out_size > 0 && bulk_out_size < 8) + return -EINVAL; + return 0; } |