CVE-2026-80931 in Linux
Sumário
de MITRE • 11/09/2026
In the Linux kernel, the following vulnerability has been resolved:
w1: ds28e17: reject an oversize length on an I2C block read
w1_f19_i2c_master_transfer() is the master_xfer for the DS28E17 1-Wire to I2C bridge. On an I2C_M_RECV_LEN read, it takes the length from the device. The downstream slave puts a length byte in buf[0]. The driver
then reads that many bytes into buf[1] with w1_f19_i2c_read().
buf[0] is controlled by the device and can be 0 to 255.
w1_f19_i2c_read() only rejects a zero count. The caller buffer is I2C_SMBUS_BLOCK_MAX + 2, so 34 bytes. A length above 32 makes the read run past it, up to about 222 bytes out of bounds.
The SMBus core does check buf[0] against I2C_SMBUS_BLOCK_MAX. That
check runs after master_xfer returns. By then the write is already done. i2c-algo-bit rejects an oversize length before it copies, and returns -EPROTO.
Reject a length above I2C_SMBUS_BLOCK_MAX at both RECV_LEN sites, the same way i2c-algo-bit does.
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