Description (CNA)
In the Linux kernel, the following vulnerability has been resolved: Input: usbtouchscreen - clamp NEXIO data_len/x_len to URB buffer size nexio_read_data() pulls data_len and x_len from a packed __be16 header in the device's interrupt packet and then walks packet->data[0..x_len) and packet->data[x_len..data_len) comparing each byte against a threshold. Both fields are 16-bit on the wire (max 65535). The existing adjustments shave at most 0x100 / 0x80 off, so the loop bound can still reach roughly 0xfeff. The URB transfer buffer for NEXIO is rept_size (1024) bytes from usb_alloc_coherent(), with the first 7 occupied by the packed header — so packet->data[] has 1017 valid bytes. read_data() callbacks are not given urb->actual_length, and nothing else bounds the walk. A device that lies about its length can get a ~64 KiB out-of-bounds read past the coherent DMA allocation. The first index whose byte exceeds NEXIO_THRESHOLD lands in begin_x / begin_y and from there into the reported touch coordinates, so adjacent kernel memory contents leak to userspace as ABS_X / ABS_Y events. Far enough out, the read can also hit an unmapped page and fault. Fix this all by clamping data_len to the buffer's data[] capacity and x_len to data_len.
Affected (CNA)
| Vendor / product | Versions |
|---|---|
| Linux / Linux | affected 5197424cdcccd2b0b1922babb93969b2515c43ce before 45c829e5eb3b974282bae50b7cca2cc891f74f0b; affected 5197424cdcccd2b0b1922babb93969b2515c43ce before e7cdcb266ba06d8480809b78ab8bb2bf8ff51ccb; affected 5197424cdcccd2b0b1922babb93969b2515c43ce before 95f47331dfde243f93e679ce70bd0c24b37c683d; affected 5197424cdcccd2b0b1922babb93969b2515c43ce before d883312061ccde8c536595998aaf687ec070077c; affected 5197424cdcccd2b0b1922babb93969b2515c43ce before 103d2de9f505f56da173e43f12dba62f92620278; affected 5197424cdcccd2b0b1922babb93969b2515c43ce before 0ca809ea8e0355299266c46e5f1755040aa8dcf3; affected 5197424cdcccd2b0b1922babb93969b2515c43ce before 7585b6aa55d8ac85ad22f522e1059f93507727b6; affected 5197424cdcccd2b0b1922babb93969b2515c43ce before 2905281cbda52ec9df540113b35b835feb5fafd3 |
| Linux / Linux | affected 2.6.34; unaffected 0 before 2.6.34; unaffected 5.10.259 through 5.10.*; unaffected 5.15.210 through 5.15.*; unaffected 6.1.176 through 6.1.*; unaffected 6.6.143 through 6.6.*; unaffected 6.12.93 through 6.12.*; unaffected 6.18.35 through 6.18.*; unaffected 7.0.12 through 7.0.*; unaffected 7.1 through * |
CWE
No CWE identifiers supplied.
References
- https://git.kernel.org/stable/c/45c829e5eb3b974282bae50b7cca2cc891f74f0b
- https://git.kernel.org/stable/c/e7cdcb266ba06d8480809b78ab8bb2bf8ff51ccb
- https://git.kernel.org/stable/c/95f47331dfde243f93e679ce70bd0c24b37c683d
- https://git.kernel.org/stable/c/d883312061ccde8c536595998aaf687ec070077c
- https://git.kernel.org/stable/c/103d2de9f505f56da173e43f12dba62f92620278
- https://git.kernel.org/stable/c/0ca809ea8e0355299266c46e5f1755040aa8dcf3
- https://git.kernel.org/stable/c/7585b6aa55d8ac85ad22f522e1059f93507727b6
- https://git.kernel.org/stable/c/2905281cbda52ec9df540113b35b835feb5fafd3