diff options
| author | Seungjin Bae <eeodqql09@gmail.com> | 2025-10-17 15:36:31 -0700 |
|---|---|---|
| committer | Dmitry Torokhov <dmitry.torokhov@gmail.com> | 2025-10-17 18:04:15 -0700 |
| commit | 69aeb507312306f73495598a055293fa749d454e (patch) | |
| tree | 403ca9c576429e2818d36664519a0475671cf7e4 /drivers/input | |
| parent | 7363096a5a08f8740c9075ecfc51945375c304bc (diff) | |
Input: pegasus-notetaker - fix potential out-of-bounds access
In the pegasus_notetaker driver, the pegasus_probe() function allocates
the URB transfer buffer using the wMaxPacketSize value from
the endpoint descriptor. An attacker can use a malicious USB descriptor
to force the allocation of a very small buffer.
Subsequently, if the device sends an interrupt packet with a specific
pattern (e.g., where the first byte is 0x80 or 0x42),
the pegasus_parse_packet() function parses the packet without checking
the allocated buffer size. This leads to an out-of-bounds memory access.
Fixes: 1afca2b66aac ("Input: add Pegasus Notetaker tablet driver")
Signed-off-by: Seungjin Bae <eeodqql09@gmail.com>
Link: https://lore.kernel.org/r/20251007214131.3737115-2-eeodqql09@gmail.com
Cc: stable@vger.kernel.org
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Diffstat (limited to 'drivers/input')
| -rw-r--r-- | drivers/input/tablet/pegasus_notetaker.c | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/drivers/input/tablet/pegasus_notetaker.c b/drivers/input/tablet/pegasus_notetaker.c index 8d6b71d59793..eabb4a0b8a0d 100644 --- a/drivers/input/tablet/pegasus_notetaker.c +++ b/drivers/input/tablet/pegasus_notetaker.c @@ -63,6 +63,9 @@ #define BUTTON_PRESSED 0xb5 #define COMMAND_VERSION 0xa9 +/* 1 Status + 1 Color + 2 X + 2 Y = 6 bytes */ +#define NOTETAKER_PACKET_SIZE 6 + /* in xy data packet */ #define BATTERY_NO_REPORT 0x40 #define BATTERY_LOW 0x41 @@ -311,6 +314,12 @@ static int pegasus_probe(struct usb_interface *intf, } pegasus->data_len = usb_maxpacket(dev, pipe); + if (pegasus->data_len < NOTETAKER_PACKET_SIZE) { + dev_err(&intf->dev, "packet size is too small (%d)\n", + pegasus->data_len); + error = -EINVAL; + goto err_free_mem; + } pegasus->data = usb_alloc_coherent(dev, pegasus->data_len, GFP_KERNEL, &pegasus->data_dma); |