{"id":"CVE-2026-97936","state":"PUBLISHED","title":"tracing: Fix memory corruption from the histogram stacktrace modifier","description":"In the Linux kernel, the following vulnerability has been resolved:\n\ntracing: Fix memory corruption from the histogram stacktrace modifier\n\nparse_field() sets HIST_FIELD_FL_STACKTRACE from the \".stacktrace\"\nmodifier before it looks the field name up, and nothing afterwards\nchecks that the name resolved to a field which holds a stacktrace.\ncreate_hist_field() picks HIST_FIELD_FN_STACK on the strength of the\nfield pointer alone, which reads a __data_loc word from the record and\nfollows its low 16 bits as an offset into the same record.\nevent_hist_trigger() takes the first word there as an entry count and\ncopies that many longs into a 31 entry array:\n\n\tn_entries = *stack;\n\tmemcpy(entries, ++stack, n_entries * sizeof(unsigned long));\n\nNeither end of that copy is bounded, and the count is whatever the event\nholds at the offset, so any field will do:\n\n  # cd /sys/kernel/tracing/events/sched/sched_process_fork\n  # echo 'hist:keys=parent_pid.stacktrace' > trigger\n  # (true)\n\n  BUG: kernel NULL pointer dereference, address: 0000000000000008\n  RIP: 0010:rb_insert_color+0x18/0x130\n   timerqueue_linked_add+0x7e/0xd0\n   enqueue_hrtimer+0x39/0xb0\n   __hrtimer_run_queues+0x10f/0x1f0\n   </IRQ>\n  RIP: 0010:memcpy+0xc/0x30\n   event_hist_trigger+0x165/0x690\n\nThe timer interrupt landed on the rbtree the copy had already run over.\nNo debug options are needed for this; KASAN reports the same write as an\nout-of-bounds read of 13835058055416381440 bytes.\n\nDocumentation/trace/histogram.rst already states the rule, \"must be a\nlong[] type\", so enforce it once the name has been resolved. Names which\nresolve to no field at all, \"hitcount.stacktrace\" and the common_*\npseudo-fields, are refused for the same reason: they hold no stacktrace\nto read.","publishedAt":"2026-09-25T10:22:50.446Z","updatedAt":"2026-10-19T09:11:02.941Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"cc5fc8bfc961eeb99b7e8dffbeff7a3f6995d314","status":"affected","lessThan":"98da3379cdee343f671dac89b9afbd8b071f2591","versionType":"git"},{"version":"cc5fc8bfc961eeb99b7e8dffbeff7a3f6995d314","status":"affected","lessThan":"e183b84968d4a6ea476d806ea97668405aa56880","versionType":"git"},{"version":"cc5fc8bfc961eeb99b7e8dffbeff7a3f6995d314","status":"affected","lessThan":"57bfc2a17954d173d2a4182f3b582ffbb23aff64","versionType":"git"},{"version":"cc5fc8bfc961eeb99b7e8dffbeff7a3f6995d314","status":"affected","lessThan":"55caaf25da2c2bb9b75307e4c868726cb954b1d6","versionType":"git"},{"version":"cc5fc8bfc961eeb99b7e8dffbeff7a3f6995d314","status":"affected","lessThan":"a5e70ba87ca8ebc79b4e63de302d03b0625fe153","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["kernel/trace/trace_events_hist.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.3","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.3","versionType":"semver"},{"version":"6.6.158","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.111","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.53","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.7","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":["kernel/trace/trace_events_hist.c"]}],"references":["https://git.kernel.org/stable/c/98da3379cdee343f671dac89b9afbd8b071f2591","https://git.kernel.org/stable/c/e183b84968d4a6ea476d806ea97668405aa56880","https://git.kernel.org/stable/c/57bfc2a17954d173d2a4182f3b582ffbb23aff64","https://git.kernel.org/stable/c/55caaf25da2c2bb9b75307e4c868726cb954b1d6","https://git.kernel.org/stable/c/a5e70ba87ca8ebc79b4e63de302d03b0625fe153"],"weaknesses":[],"ingestedAt":"2026-10-29T20:13:43.249Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/97xxx/CVE-2026-97936.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-97936","state":"PUBLISHED","datePublished":"2026-09-25T10:22:50.446Z","dateUpdated":"2026-10-19T09:11:02.941Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-09-25T10:18:58.204Z"},"containers":{"cna":{"title":"tracing: Fix memory corruption from the histogram stacktrace modifier","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\ntracing: Fix memory corruption from the histogram stacktrace modifier\n\nparse_field() sets HIST_FIELD_FL_STACKTRACE from the \".stacktrace\"\nmodifier before it looks the field name up, and nothing afterwards\nchecks that the name resolved to a field which holds a stacktrace.\ncreate_hist_field() picks HIST_FIELD_FN_STACK on the strength of the\nfield pointer alone, which reads a __data_loc word from the record and\nfollows its low 16 bits as an offset into the same record.\nevent_hist_trigger() takes the first word there as an entry count and\ncopies that many longs into a 31 entry array:\n\n\tn_entries = *stack;\n\tmemcpy(entries, ++stack, n_entries * sizeof(unsigned long));\n\nNeither end of that copy is bounded, and the count is whatever the event\nholds at the offset, so any field will do:\n\n  # cd /sys/kernel/tracing/events/sched/sched_process_fork\n  # echo 'hist:keys=parent_pid.stacktrace' > trigger\n  # (true)\n\n  BUG: kernel NULL pointer dereference, address: 0000000000000008\n  RIP: 0010:rb_insert_color+0x18/0x130\n   timerqueue_linked_add+0x7e/0xd0\n   enqueue_hrtimer+0x39/0xb0\n   __hrtimer_run_queues+0x10f/0x1f0\n   </IRQ>\n  RIP: 0010:memcpy+0xc/0x30\n   event_hist_trigger+0x165/0x690\n\nThe timer interrupt landed on the rbtree the copy had already run over.\nNo debug options are needed for this; KASAN reports the same write as an\nout-of-bounds read of 13835058055416381440 bytes.\n\nDocumentation/trace/histogram.rst already states the rule, \"must be a\nlong[] type\", so enforce it once the name has been resolved. Names which\nresolve to no field at all, \"hitcount.stacktrace\" and the common_*\npseudo-fields, are refused for the same reason: they hold no stacktrace\nto read."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"cc5fc8bfc961eeb99b7e8dffbeff7a3f6995d314","status":"affected","lessThan":"98da3379cdee343f671dac89b9afbd8b071f2591","versionType":"git"},{"version":"cc5fc8bfc961eeb99b7e8dffbeff7a3f6995d314","status":"affected","lessThan":"e183b84968d4a6ea476d806ea97668405aa56880","versionType":"git"},{"version":"cc5fc8bfc961eeb99b7e8dffbeff7a3f6995d314","status":"affected","lessThan":"57bfc2a17954d173d2a4182f3b582ffbb23aff64","versionType":"git"},{"version":"cc5fc8bfc961eeb99b7e8dffbeff7a3f6995d314","status":"affected","lessThan":"55caaf25da2c2bb9b75307e4c868726cb954b1d6","versionType":"git"},{"version":"cc5fc8bfc961eeb99b7e8dffbeff7a3f6995d314","status":"affected","lessThan":"a5e70ba87ca8ebc79b4e63de302d03b0625fe153","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["kernel/trace/trace_events_hist.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.3","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.3","versionType":"semver"},{"version":"6.6.158","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.111","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.53","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.7","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":["kernel/trace/trace_events_hist.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/98da3379cdee343f671dac89b9afbd8b071f2591"},{"url":"https://git.kernel.org/stable/c/e183b84968d4a6ea476d806ea97668405aa56880"},{"url":"https://git.kernel.org/stable/c/57bfc2a17954d173d2a4182f3b582ffbb23aff64"},{"url":"https://git.kernel.org/stable/c/55caaf25da2c2bb9b75307e4c868726cb954b1d6"},{"url":"https://git.kernel.org/stable/c/a5e70ba87ca8ebc79b4e63de302d03b0625fe153"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-10-19T09:11:02.941Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.3","versionEndExcluding":"6.6.158"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.3","versionEndExcluding":"6.12.111"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.3","versionEndExcluding":"6.18.53"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.3","versionEndExcluding":"7.2.7"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.3","versionEndExcluding":"7.3"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}