{"id":"CVE-2026-80931","summary":"w1: ds28e17: reject an oversize length on an I2C block read","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nw1: ds28e17: reject an oversize length on an I2C block read\n\nw1_f19_i2c_master_transfer() is the master_xfer for the DS28E17 1-Wire\nto I2C bridge. On an I2C_M_RECV_LEN read, it takes the length from the\ndevice. The downstream slave puts a length byte in buf[0]. The driver\nthen reads that many bytes into buf[1] with w1_f19_i2c_read().\n\nbuf[0] is controlled by the device and can be 0 to 255.\nw1_f19_i2c_read() only rejects a zero count. The caller buffer is\nI2C_SMBUS_BLOCK_MAX + 2, so 34 bytes. A length above 32 makes the read\nrun past it, up to about 222 bytes out of bounds.\n\nThe SMBus core does check buf[0] against I2C_SMBUS_BLOCK_MAX. That\ncheck runs after master_xfer returns. By then the write is already\ndone. i2c-algo-bit rejects an oversize length before it copies, and\nreturns -EPROTO.\n\nReject a length above I2C_SMBUS_BLOCK_MAX at both RECV_LEN sites, the\nsame way i2c-algo-bit does.","modified":"2026-09-13T03:46:46.832928455Z","published":"2026-09-11T19:42:06.272Z","database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/80xxx/CVE-2026-80931.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/169ae5e65e5aaf213b6a578f6478a9fd2e523606"},{"type":"WEB","url":"https://git.kernel.org/stable/c/6df05f630c84a109736642362e452089886f9974"},{"type":"WEB","url":"https://git.kernel.org/stable/c/ae0c79a8527044e54d81fd5a3b49ce6177633758"},{"type":"WEB","url":"https://git.kernel.org/stable/c/cb55c5da9828f77db2a2701316949d4de1e9b773"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/80xxx/CVE-2026-80931.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-80931"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"ebc4768ac4971eab4b570e733e47ac9dfd0e4175"},{"fixed":"cb55c5da9828f77db2a2701316949d4de1e9b773"},{"fixed":"ae0c79a8527044e54d81fd5a3b49ce6177633758"},{"fixed":"6df05f630c84a109736642362e452089886f9974"},{"fixed":"169ae5e65e5aaf213b6a578f6478a9fd2e523606"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-80931.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"4.15.0"},{"fixed":"6.12.109"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.18.50"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.2.4"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-80931.json"}}],"schema_version":"1.9.0"}