{"id":"CVE-2026-80931","state":"PUBLISHED","title":"w1: ds28e17: reject an oversize length on an I2C block read","description":"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.","publishedAt":"2026-09-11T19:42:06.272Z","updatedAt":"2026-10-19T08:45:15.065Z","severity":{"score":7.8,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"ebc4768ac4971eab4b570e733e47ac9dfd0e4175","status":"affected","lessThan":"b30c021c6073559ea6851b522d8a17a524a27b4a","versionType":"git"},{"version":"ebc4768ac4971eab4b570e733e47ac9dfd0e4175","status":"affected","lessThan":"1d08877fc37e90945df38d255715bd1d6c052d46","versionType":"git"},{"version":"ebc4768ac4971eab4b570e733e47ac9dfd0e4175","status":"affected","lessThan":"bf76d61e118b7044600a65775a3bf8adc2c6823d","versionType":"git"},{"version":"ebc4768ac4971eab4b570e733e47ac9dfd0e4175","status":"affected","lessThan":"0f6496b34cc2919420f303b2aabdd9f71e084b56","versionType":"git"},{"version":"ebc4768ac4971eab4b570e733e47ac9dfd0e4175","status":"affected","lessThan":"cb55c5da9828f77db2a2701316949d4de1e9b773","versionType":"git"},{"version":"ebc4768ac4971eab4b570e733e47ac9dfd0e4175","status":"affected","lessThan":"ae0c79a8527044e54d81fd5a3b49ce6177633758","versionType":"git"},{"version":"ebc4768ac4971eab4b570e733e47ac9dfd0e4175","status":"affected","lessThan":"6df05f630c84a109736642362e452089886f9974","versionType":"git"},{"version":"ebc4768ac4971eab4b570e733e47ac9dfd0e4175","status":"affected","lessThan":"169ae5e65e5aaf213b6a578f6478a9fd2e523606","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/w1/slaves/w1_ds28e17.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"4.15","status":"affected"},{"version":"0","status":"unaffected","lessThan":"4.15","versionType":"semver"},{"version":"5.10.270","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.221","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.188","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.157","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.109","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.50","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.4","status":"unaffected","lessThanOrEqual":"7.2.*","versionType":"semver"},{"version":"7.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/w1/slaves/w1_ds28e17.c"]}],"references":["https://git.kernel.org/stable/c/b30c021c6073559ea6851b522d8a17a524a27b4a","https://git.kernel.org/stable/c/1d08877fc37e90945df38d255715bd1d6c052d46","https://git.kernel.org/stable/c/bf76d61e118b7044600a65775a3bf8adc2c6823d","https://git.kernel.org/stable/c/0f6496b34cc2919420f303b2aabdd9f71e084b56","https://git.kernel.org/stable/c/cb55c5da9828f77db2a2701316949d4de1e9b773","https://git.kernel.org/stable/c/ae0c79a8527044e54d81fd5a3b49ce6177633758","https://git.kernel.org/stable/c/6df05f630c84a109736642362e452089886f9974","https://git.kernel.org/stable/c/169ae5e65e5aaf213b6a578f6478a9fd2e523606"],"weaknesses":[],"ingestedAt":"2026-10-29T20:13:07.220Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/80xxx/CVE-2026-80931.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-80931","state":"PUBLISHED","datePublished":"2026-09-11T19:42:06.272Z","dateUpdated":"2026-10-19T08:45:15.065Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-08-26T14:34:25.802Z"},"containers":{"cna":{"title":"w1: ds28e17: reject an oversize length on an I2C block read","descriptions":[{"lang":"en","value":"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."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"ebc4768ac4971eab4b570e733e47ac9dfd0e4175","status":"affected","lessThan":"b30c021c6073559ea6851b522d8a17a524a27b4a","versionType":"git"},{"version":"ebc4768ac4971eab4b570e733e47ac9dfd0e4175","status":"affected","lessThan":"1d08877fc37e90945df38d255715bd1d6c052d46","versionType":"git"},{"version":"ebc4768ac4971eab4b570e733e47ac9dfd0e4175","status":"affected","lessThan":"bf76d61e118b7044600a65775a3bf8adc2c6823d","versionType":"git"},{"version":"ebc4768ac4971eab4b570e733e47ac9dfd0e4175","status":"affected","lessThan":"0f6496b34cc2919420f303b2aabdd9f71e084b56","versionType":"git"},{"version":"ebc4768ac4971eab4b570e733e47ac9dfd0e4175","status":"affected","lessThan":"cb55c5da9828f77db2a2701316949d4de1e9b773","versionType":"git"},{"version":"ebc4768ac4971eab4b570e733e47ac9dfd0e4175","status":"affected","lessThan":"ae0c79a8527044e54d81fd5a3b49ce6177633758","versionType":"git"},{"version":"ebc4768ac4971eab4b570e733e47ac9dfd0e4175","status":"affected","lessThan":"6df05f630c84a109736642362e452089886f9974","versionType":"git"},{"version":"ebc4768ac4971eab4b570e733e47ac9dfd0e4175","status":"affected","lessThan":"169ae5e65e5aaf213b6a578f6478a9fd2e523606","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/w1/slaves/w1_ds28e17.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"4.15","status":"affected"},{"version":"0","status":"unaffected","lessThan":"4.15","versionType":"semver"},{"version":"5.10.270","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.221","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.188","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.157","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.109","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.50","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.4","status":"unaffected","lessThanOrEqual":"7.2.*","versionType":"semver"},{"version":"7.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/w1/slaves/w1_ds28e17.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/b30c021c6073559ea6851b522d8a17a524a27b4a"},{"url":"https://git.kernel.org/stable/c/1d08877fc37e90945df38d255715bd1d6c052d46"},{"url":"https://git.kernel.org/stable/c/bf76d61e118b7044600a65775a3bf8adc2c6823d"},{"url":"https://git.kernel.org/stable/c/0f6496b34cc2919420f303b2aabdd9f71e084b56"},{"url":"https://git.kernel.org/stable/c/cb55c5da9828f77db2a2701316949d4de1e9b773"},{"url":"https://git.kernel.org/stable/c/ae0c79a8527044e54d81fd5a3b49ce6177633758"},{"url":"https://git.kernel.org/stable/c/6df05f630c84a109736642362e452089886f9974"},{"url":"https://git.kernel.org/stable/c/169ae5e65e5aaf213b6a578f6478a9fd2e523606"}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","baseScore":7.8,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:L - The overflow is reached from local userspace via /dev/i2c-* I2C_SMBUS or I2C_RDWR ioctls into w1_f19_i2c_master_transfer() on the DS28E17-created I2C adapter; i2c-dev does not require advertised I2C_FUNC_SMBUS_READ_BLOCK_DATA. There is no network path; the 1-Wire-to-I2C bridge being present is a deployment precondition.\nAC:L - A single I2C_M_RECV_LEN block read uses the downstream slave's first data byte as the extra length with no cap, then w1_f19_i2c_read() copies that many bytes. The attacker chooses the ioctl and target address; a responding slave returning >32 (or data the attacker just wrote) overflows reliably, with no race or uncontrolled layout.\nPR:L - i2cdev_open() has no capability check; reachability depends only on /dev/i2c-* permissions, commonly 0660 root:i2c on embedded and industrial systems. That is unprivileged local access, not real init-namespace root.\nUI:N - The attacker triggers the bug with their own open/ioctl sequence on an already-present DS28E17 I2C adapter node. No victim action such as plugging in a device or mounting a filesystem is required.\nS:U - Impact is ordinary host-kernel stack or heap corruption of the SMBus/i2c-dev transfer buffer within the same kernel authority. It does not cross a VM, IOMMU, or other separate security boundary.\nC:H - A device-supplied length up to 255 causes an out-of-bounds write of about 222 bytes past the 34-byte I2C_SMBUS_BLOCK_MAX+2 buffer into adjacent kernel stack or heap. That memory corruption is defensibly leveraged for kernel information disclosure.\nI:H - Slave-controlled bytes are written past the end of the kernel transfer buffer, producing a substantial out-of-bounds kernel write. Such corruption is exploitable for arbitrary memory modification or control-flow hijacking.\nA:H - The out-of-bounds kernel write can corrupt heap or stack state and cause an oops, panic, or hang. The attacker can repeat the local ioctl to deny service."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-10-19T08:45:15.065Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.15","versionEndExcluding":"5.10.270"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.15","versionEndExcluding":"5.15.221"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.15","versionEndExcluding":"6.1.188"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.15","versionEndExcluding":"6.6.157"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.15","versionEndExcluding":"6.12.109"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.15","versionEndExcluding":"6.18.50"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.15","versionEndExcluding":"7.2.4"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.15","versionEndExcluding":"7.3"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}