CVE-2026-97936

CVE CVE-2026-97936EUVD EUVD-2026-86790Published 2026-09-25T10:22:50.000Z

What the advisory describes

In the Linux kernel, the following vulnerability has been resolved: tracing: Fix memory corruption from the histogram stacktrace modifier parse_field() sets HIST_FIELD_FL_STACKTRACE from the ".stacktrace" modifier before it looks the field name up, and nothing afterwards checks that the name resolved to a field which holds a stacktrace. create_hist_field() picks HIST_FIELD_FN_STACK on the strength of the field pointer alone, which reads a __data_loc word from the record and follows its low 16 bits as an offset into the same record. event_hist_trigger() takes the first word there as an entry count and copies that many longs into a 31 entry array: n_entries = *stack; memcpy(entries, ++stack, n_entries * sizeof(unsigned long)); Neither end of that copy is bounded, and the count is whatever the event holds at the offset, so any field will do: # cd /sys/kernel/tracing/events/sched/sched_process_fork # echo 'hist:keys=parent_pid.stacktrace' > trigger # (true) BUG: kernel NULL pointer dereference, address: 0000000000000008 RIP: 0010:rb_insert_color+0x18/0x130 timerqueue_linked_add+0x7e/0xd0 enqueue_hrtimer+0x39/0xb0 __hrtimer_run_queues+0x10f/0x1f0 </IRQ> RIP: 0010:memcpy+0xc/0x30 event_hist_trigger+0x165/0x690 The timer interrupt landed on the rbtree the copy had already run over. No debug options are needed for this; KASAN reports the same write as an out-of-bounds read of 13835058055416381440 bytes. Documentation/trace/histogram.rst already states the rule, "must be a long[] type", so enforce it once the name has been resolved. Names which resolve to no field at all, "hitcount.stacktrace" and the common_* pseudo-fields, are refused for the same reason: they hold no stacktrace to read.

Source: EUVD (ENISA), in the words of the advisory.

Products the advisory names

These come from the advisory itself, not from any check we performed.

• Linux — Linux patch: 6.18.53; 6.3; patch: 7.2.7; patch: 0; cc5fc8bfc961eeb99b7e8dffbeff7a3f6995d314 <55caaf25da2c2bb9b75307e4c868726cb954b1d6; patch: 6.12.111; cc5fc8bfc961eeb99b7e8dffbeff7a3f6995d314 <57bfc2a17954d173d2a4182f3b582ffbb23aff64; cc5fc8bfc961eeb99b7e8dffbeff7a3f6995d314 <e183b84968d4a6ea476d806ea97668405aa56880; patch: 7.3-rc3; cc5fc8bfc961eeb99b7e8dffbeff7a3f6995d314 <a5e70ba87ca8ebc79b4e63de302d03b0625fe153

The versions shown are the advisory's own. Patchlage compares no version numbers and derives no judgement from them — which version is installed is something a person has to look up.

Carried in the product catalogue

An estate covering these products can be recorded in Patchlage. An advisory about them appears in the next morning's situation report.

• Linux — Linux

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