{"api_version":"1","generated_at":"2026-08-16T21:43:15+00:00","cve":"CVE-2026-72135","urls":{"html":"https://cve.report/CVE-2026-72135","api":"https://cve.report/api/cve/CVE-2026-72135.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-72135","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-72135"},"summary":{"title":"tpm: Make the TPM character devices non-seekable","description":"In the Linux kernel, the following vulnerability has been resolved:\n\ntpm: Make the TPM character devices non-seekable\n\nThe TPM character devices expose a sequential command/response\ninterface, but their open handlers leave FMODE_PREAD and FMODE_PWRITE\nenabled.\n\nAfter a command leaves a response pending, pread(fd, buf, 16, 0x1400)\npasses 0x1400 as *off to tpm_common_read(). The transfer length is\nbounded by response_length, but the offset is used unchecked when\nforming data_buffer + *off. A sufficiently large offset therefore causes\nan out-of-bounds heap read through copy_to_user() and, if the copy\nsucceeds, an out-of-bounds zero-write through the following memset().\n\nPositional I/O does not provide coherent semantics for this interface.\nAn arbitrary pread offset cannot represent how much of a response has\nbeen consumed sequentially. The write callback always stores a command\nat the start of data_buffer, while pwrite() does not update file->f_pos\nand can leave the sequential read cursor stale.\n\nCall nonseekable_open() from both open handlers. This removes\nFMODE_PREAD and FMODE_PWRITE, causing positional reads and writes to\nfail with -ESPIPE before reaching the TPM callbacks, and explicitly\nmarks the files non-seekable. Normal read() and write() continue to use\nthe existing sequential f_pos cursor, leaving the response state machine\nunchanged.\n\nTested on Linux 6.12 with KASAN and a swtpm TPM2 device:\n\n - sequential partial reads returned the complete response\n - pread() and preadv() with offset 0x1400 returned -ESPIPE\n - pwrite() and pwritev() with offset zero returned -ESPIPE\n - the pending response remained intact after the rejected operations\n - a subsequent normal command/response cycle completed normally\n - no KASAN report was produced.","state":"PUBLISHED","assigner":"Linux","published_at":"2026-08-15 06:21:30","updated_at":"2026-08-15 06:21:30"},"problem_types":[],"metrics":[],"references":[{"url":"https://git.kernel.org/stable/c/dda695fab5e21f923d29e8cb01df256468ddfbd1","name":"https://git.kernel.org/stable/c/dda695fab5e21f923d29e8cb01df256468ddfbd1","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/f20d61c22bcaf172d6790b6500e3838e532e71c8","name":"https://git.kernel.org/stable/c/f20d61c22bcaf172d6790b6500e3838e532e71c8","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/21a13f932972bc9836f58c44fcd47c62abdecd95","name":"https://git.kernel.org/stable/c/21a13f932972bc9836f58c44fcd47c62abdecd95","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/947b773caaa548672184df025271b29bdc80b0f1","name":"https://git.kernel.org/stable/c/947b773caaa548672184df025271b29bdc80b0f1","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/ada4b9a5087ea7f30dd8e4c6411a4fb6547eb1ed","name":"https://git.kernel.org/stable/c/ada4b9a5087ea7f30dd8e4c6411a4fb6547eb1ed","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/ed0ffc2c016629e40ba041ed0424a772d8b02e2c","name":"https://git.kernel.org/stable/c/ed0ffc2c016629e40ba041ed0424a772d8b02e2c","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/232dcf908eb7eb9d8046a9597975caf44270966e","name":"https://git.kernel.org/stable/c/232dcf908eb7eb9d8046a9597975caf44270966e","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/9c513dabd4540f811585a2087f23069767a284da","name":"https://git.kernel.org/stable/c/9c513dabd4540f811585a2087f23069767a284da","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-72135","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-72135","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 9488585b21bef0df1217e510c7134905d1d376a7 ed0ffc2c016629e40ba041ed0424a772d8b02e2c git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 9488585b21bef0df1217e510c7134905d1d376a7 232dcf908eb7eb9d8046a9597975caf44270966e git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 9488585b21bef0df1217e510c7134905d1d376a7 dda695fab5e21f923d29e8cb01df256468ddfbd1 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 9488585b21bef0df1217e510c7134905d1d376a7 9c513dabd4540f811585a2087f23069767a284da git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 9488585b21bef0df1217e510c7134905d1d376a7 21a13f932972bc9836f58c44fcd47c62abdecd95 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 9488585b21bef0df1217e510c7134905d1d376a7 ada4b9a5087ea7f30dd8e4c6411a4fb6547eb1ed git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 9488585b21bef0df1217e510c7134905d1d376a7 947b773caaa548672184df025271b29bdc80b0f1 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 9488585b21bef0df1217e510c7134905d1d376a7 f20d61c22bcaf172d6790b6500e3838e532e71c8 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 5.0","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 5.0 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 5.10.261 5.10.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 5.15.212 5.15.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.1.178 6.1.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.6.145 6.6.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.12.97 6.12.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.18.40 6.18.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.1.5 7.1.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.2-rc3 * original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":{"cve_year":"2026","cve_id":"72135","cve":"CVE-2026-72135","epss":"0.002200000","percentile":"0.127340000","score_date":"2026-08-15","updated_at":"2026-08-16 00:00:32"},"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["drivers/char/tpm/tpm-dev.c","drivers/char/tpm/tpmrm-dev.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"ed0ffc2c016629e40ba041ed0424a772d8b02e2c","status":"affected","version":"9488585b21bef0df1217e510c7134905d1d376a7","versionType":"git"},{"lessThan":"232dcf908eb7eb9d8046a9597975caf44270966e","status":"affected","version":"9488585b21bef0df1217e510c7134905d1d376a7","versionType":"git"},{"lessThan":"dda695fab5e21f923d29e8cb01df256468ddfbd1","status":"affected","version":"9488585b21bef0df1217e510c7134905d1d376a7","versionType":"git"},{"lessThan":"9c513dabd4540f811585a2087f23069767a284da","status":"affected","version":"9488585b21bef0df1217e510c7134905d1d376a7","versionType":"git"},{"lessThan":"21a13f932972bc9836f58c44fcd47c62abdecd95","status":"affected","version":"9488585b21bef0df1217e510c7134905d1d376a7","versionType":"git"},{"lessThan":"ada4b9a5087ea7f30dd8e4c6411a4fb6547eb1ed","status":"affected","version":"9488585b21bef0df1217e510c7134905d1d376a7","versionType":"git"},{"lessThan":"947b773caaa548672184df025271b29bdc80b0f1","status":"affected","version":"9488585b21bef0df1217e510c7134905d1d376a7","versionType":"git"},{"lessThan":"f20d61c22bcaf172d6790b6500e3838e532e71c8","status":"affected","version":"9488585b21bef0df1217e510c7134905d1d376a7","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["drivers/char/tpm/tpm-dev.c","drivers/char/tpm/tpmrm-dev.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"5.0"},{"lessThan":"5.0","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"5.10.*","status":"unaffected","version":"5.10.261","versionType":"semver"},{"lessThanOrEqual":"5.15.*","status":"unaffected","version":"5.15.212","versionType":"semver"},{"lessThanOrEqual":"6.1.*","status":"unaffected","version":"6.1.178","versionType":"semver"},{"lessThanOrEqual":"6.6.*","status":"unaffected","version":"6.6.145","versionType":"semver"},{"lessThanOrEqual":"6.12.*","status":"unaffected","version":"6.12.97","versionType":"semver"},{"lessThanOrEqual":"6.18.*","status":"unaffected","version":"6.18.40","versionType":"semver"},{"lessThanOrEqual":"7.1.*","status":"unaffected","version":"7.1.5","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"7.2-rc3","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"5.10.261","versionStartIncluding":"5.0","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"5.15.212","versionStartIncluding":"5.0","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.1.178","versionStartIncluding":"5.0","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.6.145","versionStartIncluding":"5.0","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.12.97","versionStartIncluding":"5.0","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.18.40","versionStartIncluding":"5.0","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.1.5","versionStartIncluding":"5.0","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.2-rc3","versionStartIncluding":"5.0","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\ntpm: Make the TPM character devices non-seekable\n\nThe TPM character devices expose a sequential command/response\ninterface, but their open handlers leave FMODE_PREAD and FMODE_PWRITE\nenabled.\n\nAfter a command leaves a response pending, pread(fd, buf, 16, 0x1400)\npasses 0x1400 as *off to tpm_common_read(). The transfer length is\nbounded by response_length, but the offset is used unchecked when\nforming data_buffer + *off. A sufficiently large offset therefore causes\nan out-of-bounds heap read through copy_to_user() and, if the copy\nsucceeds, an out-of-bounds zero-write through the following memset().\n\nPositional I/O does not provide coherent semantics for this interface.\nAn arbitrary pread offset cannot represent how much of a response has\nbeen consumed sequentially. The write callback always stores a command\nat the start of data_buffer, while pwrite() does not update file->f_pos\nand can leave the sequential read cursor stale.\n\nCall nonseekable_open() from both open handlers. This removes\nFMODE_PREAD and FMODE_PWRITE, causing positional reads and writes to\nfail with -ESPIPE before reaching the TPM callbacks, and explicitly\nmarks the files non-seekable. Normal read() and write() continue to use\nthe existing sequential f_pos cursor, leaving the response state machine\nunchanged.\n\nTested on Linux 6.12 with KASAN and a swtpm TPM2 device:\n\n - sequential partial reads returned the complete response\n - pread() and preadv() with offset 0x1400 returned -ESPIPE\n - pwrite() and pwritev() with offset zero returned -ESPIPE\n - the pending response remained intact after the rejected operations\n - a subsequent normal command/response cycle completed normally\n - no KASAN report was produced."}],"providerMetadata":{"dateUpdated":"2026-08-15T05:53:10.315Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/ed0ffc2c016629e40ba041ed0424a772d8b02e2c"},{"url":"https://git.kernel.org/stable/c/232dcf908eb7eb9d8046a9597975caf44270966e"},{"url":"https://git.kernel.org/stable/c/dda695fab5e21f923d29e8cb01df256468ddfbd1"},{"url":"https://git.kernel.org/stable/c/9c513dabd4540f811585a2087f23069767a284da"},{"url":"https://git.kernel.org/stable/c/21a13f932972bc9836f58c44fcd47c62abdecd95"},{"url":"https://git.kernel.org/stable/c/ada4b9a5087ea7f30dd8e4c6411a4fb6547eb1ed"},{"url":"https://git.kernel.org/stable/c/947b773caaa548672184df025271b29bdc80b0f1"},{"url":"https://git.kernel.org/stable/c/f20d61c22bcaf172d6790b6500e3838e532e71c8"}],"title":"tpm: Make the TPM character devices non-seekable","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-72135","datePublished":"2026-08-15T05:53:10.315Z","dateReserved":"2026-08-09T03:40:39.907Z","dateUpdated":"2026-08-15T05:53:10.315Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-08-15 06:21:30","lastModifiedDate":"2026-08-15 06:21:30","problem_types":[],"metrics":[],"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"72135","Ordinal":"1","Title":"tpm: Make the TPM character devices non-seekable","CVE":"CVE-2026-72135","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"72135","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\ntpm: Make the TPM character devices non-seekable\n\nThe TPM character devices expose a sequential command/response\ninterface, but their open handlers leave FMODE_PREAD and FMODE_PWRITE\nenabled.\n\nAfter a command leaves a response pending, pread(fd, buf, 16, 0x1400)\npasses 0x1400 as *off to tpm_common_read(). The transfer length is\nbounded by response_length, but the offset is used unchecked when\nforming data_buffer + *off. A sufficiently large offset therefore causes\nan out-of-bounds heap read through copy_to_user() and, if the copy\nsucceeds, an out-of-bounds zero-write through the following memset().\n\nPositional I/O does not provide coherent semantics for this interface.\nAn arbitrary pread offset cannot represent how much of a response has\nbeen consumed sequentially. The write callback always stores a command\nat the start of data_buffer, while pwrite() does not update file->f_pos\nand can leave the sequential read cursor stale.\n\nCall nonseekable_open() from both open handlers. This removes\nFMODE_PREAD and FMODE_PWRITE, causing positional reads and writes to\nfail with -ESPIPE before reaching the TPM callbacks, and explicitly\nmarks the files non-seekable. Normal read() and write() continue to use\nthe existing sequential f_pos cursor, leaving the response state machine\nunchanged.\n\nTested on Linux 6.12 with KASAN and a swtpm TPM2 device:\n\n - sequential partial reads returned the complete response\n - pread() and preadv() with offset 0x1400 returned -ESPIPE\n - pwrite() and pwritev() with offset zero returned -ESPIPE\n - the pending response remained intact after the rejected operations\n - a subsequent normal command/response cycle completed normally\n - no KASAN report was produced.","Type":"Description","Title":"tpm: Make the TPM character devices non-seekable"}]}}}