Description
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 products
Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.
Linux Linux
Default version status: unaffected
5197424cdcccd2b0b1922babb93969b2515c43ce to < 45c829e5eb3b974282bae50b7cca2cc891f74f0baffected5197424cdcccd2b0b1922babb93969b2515c43ce to < e7cdcb266ba06d8480809b78ab8bb2bf8ff51ccbaffected5197424cdcccd2b0b1922babb93969b2515c43ce to < 95f47331dfde243f93e679ce70bd0c24b37c683daffected5197424cdcccd2b0b1922babb93969b2515c43ce to < d883312061ccde8c536595998aaf687ec070077caffected5197424cdcccd2b0b1922babb93969b2515c43ce to < 103d2de9f505f56da173e43f12dba62f92620278affected5197424cdcccd2b0b1922babb93969b2515c43ce to < 0ca809ea8e0355299266c46e5f1755040aa8dcf3affected5197424cdcccd2b0b1922babb93969b2515c43ce to < 7585b6aa55d8ac85ad22f522e1059f93507727b6affected5197424cdcccd2b0b1922babb93969b2515c43ce to < 2905281cbda52ec9df540113b35b835feb5fafd3affected
Linux Linux
Default version status: affected
2.6.34affected0 to < 2.6.34unaffected5.10.259 to ≤ 5.10.*unaffected5.15.210 to ≤ 5.15.*unaffected6.1.176 to ≤ 6.1.*unaffected6.6.143 to ≤ 6.6.*unaffected6.12.93 to ≤ 6.12.*unaffected6.18.35 to ≤ 6.18.*unaffected7.0.12 to ≤ 7.0.*unaffected7.1 to ≤ *unaffected
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 ↗