w1: ds28e17: reject an oversize length on an I2C block read

Overview

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.

Affected

• Linux >= ebc4768ac4971eab4b570e733e47ac9dfd0e4175 < b30c021c6073559ea6851b522d8a17a524a27b4a
• Linux >= ebc4768ac4971eab4b570e733e47ac9dfd0e4175 < 1d08877fc37e90945df38d255715bd1d6c052d46
• Linux >= ebc4768ac4971eab4b570e733e47ac9dfd0e4175 < bf76d61e118b7044600a65775a3bf8adc2c6823d
• Linux >= ebc4768ac4971eab4b570e733e47ac9dfd0e4175 < 0f6496b34cc2919420f303b2aabdd9f71e084b56
• Linux >= ebc4768ac4971eab4b570e733e47ac9dfd0e4175 < cb55c5da9828f77db2a2701316949d4de1e9b773
• Linux >= ebc4768ac4971eab4b570e733e47ac9dfd0e4175 < ae0c79a8527044e54d81fd5a3b49ce6177633758
• Linux >= ebc4768ac4971eab4b570e733e47ac9dfd0e4175 < 6df05f630c84a109736642362e452089886f9974
• Linux >= ebc4768ac4971eab4b570e733e47ac9dfd0e4175 < 169ae5e65e5aaf213b6a578f6478a9fd2e523606
• Linux 4.15

Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.

Vendor advisories

• Red Hat VEX · Moderate · updated 2026-09-14 · vex