{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-99236","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2026-09-25T10:25:14.402Z","datePublished":"2026-11-02T16:06:41.950Z","dateUpdated":"2026-11-03T19:13:04.332Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-11-03T19:13:04.332Z"},"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\ntracing: Reject incomplete event filter expressions\n\nA non-empty expression normally finishes in predicate_parse()'s inner\nloop, which resolves the pending logical operators before jumping to\nfinalization. If the input ends after an operator, possibly followed by\nunary '!' tokens, the outer loop instead falls through with unresolved\noperator state.\n\nFor example, \"common_pid == 1 || common_pid == 2 &&\" leaves\nprog[0].target equal to -1. The second pass then reads prog[-1] before\nthe forward-jump check can reject it. Depending on adjacent slab\ncontents, it can also copy an out-of-bounds word into a branch target\nthat passes the forward-only check. A self-targeted perf tracepoint\ncounting event can reach this path through PERF_EVENT_IOC_SET_FILTER.\n\nReject the outer-loop fallthrough when a predicate has already been\nparsed. This ensures that non-empty expressions only reach finalization\nafter the inner loop has resolved their operators. Keep the existing\nno-filter error for input that has no predicates. Add a regression test\nfor trailing logical operators and unary negations."}],"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 incomplete expression is copied from userspace by perf_event_set_filter() via ioctl(PERF_EVENT_IOC_SET_FILTER) on a PERF_TYPE_TRACEPOINT fd, then passed to ftrace_profile_set_filter(), create_filter(), process_preds(), and the patched predicate_parse(). No network protocol carries the filter string.\nAC:L - A trailing operator such as \"common_pid == 1 || common_pid == 2 &&\" makes predicate_parse() leave the outer loop with N>0 and prog[0].target still -1, so the second pass always reads prog[-1]. No race or admin-triggered state is required; a positive copied target that passes the forward-only check can be placed in the adjacent kmalloc object by heap spray.\nPR:L - An unprivileged process can open a self-targeted PERF_TYPE_TRACEPOINT counting event with exclude_kernel=1 and no PERF_SAMPLE_RAW: sys_perf_event_open() skips perf_allow_kernel(), and perf_trace_event_perm() returns 0 before perf_allow_tracepoint(). The same fd's owner then calls PERF_EVENT_IOC_SET_FILTER.\nUI:N - The attacking process itself performs perf_event_open() and ioctl(PERF_EVENT_IOC_SET_FILTER); no other user must mount a filesystem, write a tracefs filter file, or otherwise act.\nS:U - predicate_parse() underflows the kmalloc'd prog_stack in the host kernel that already enforces perf access; a resulting local kernel memory-safety issue does not cross a guest-host, IOMMU, or other security authority.\nC:H - The second pass reads prog[-1] and may copy its target into prog[0]. filter_match_preds() then uses that value as a program index, so a large copied word walks off the allocation and interprets heap as struct filter_pred, which is an unbounded kernel read rather than a few-byte leak.\nI:H - A groomed out-of-range prog_entry can make filter_match_preds() call filter_pred_fn_call() on a fake filter_pred. FILTER_PRED_FN_STRING reaches pred->regex->match, an attacker-influenced function pointer, so the corrupted branch target is exploitable for control-flow hijack rather than only a counting mismatch.\nA:H - With a wild target, filter_match_preds() dereferences prog[i].pred off the allocation. A sys_enter_* counting event still evaluates the filter because perf_syscall_enter() passes user pt_regs, so user_mode() is true and exclude_kernel=1 does not skip perf_tp_filter_match(); the attacker then oopses the kernel by making a syscall."}]}],"affected":[{"product":"Linux","vendor":"Linux","defaultStatus":"unaffected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["kernel/trace/trace_events_filter.c","tools/testing/selftests/ftrace/test.d/filter/event-filter-incomplete.tc"],"versions":[{"version":"80765597bc587feae8dbc8ce97a0f32e12a6e625","lessThan":"4a1a6d35359991c5d47f4bf101cfbe1475c94093","status":"affected","versionType":"git"},{"version":"80765597bc587feae8dbc8ce97a0f32e12a6e625","lessThan":"2a98f5d4913ec081e08e1075512cb7ec313d9f72","status":"affected","versionType":"git"},{"version":"80765597bc587feae8dbc8ce97a0f32e12a6e625","lessThan":"15ff3cc7f2beecc3f95d66358f20ad7b057466aa","status":"affected","versionType":"git"},{"version":"80765597bc587feae8dbc8ce97a0f32e12a6e625","lessThan":"b205ff58e02922ac324f931cf9eb238a3acdb048","status":"affected","versionType":"git"},{"version":"80765597bc587feae8dbc8ce97a0f32e12a6e625","lessThan":"5a999b5a16530898f0dbe5f8c50fd45ea72e110b","status":"affected","versionType":"git"},{"version":"80765597bc587feae8dbc8ce97a0f32e12a6e625","lessThan":"1008e9e0b8280d47f1ab5e9c113f666a023a9697","status":"affected","versionType":"git"},{"version":"80765597bc587feae8dbc8ce97a0f32e12a6e625","lessThan":"64993d970dde2a2da353e9e99595a4fa88ec27d9","status":"affected","versionType":"git"},{"version":"80765597bc587feae8dbc8ce97a0f32e12a6e625","lessThan":"5bcdf3c18c3471122ee9652b0e2f5cdb718d9a46","status":"affected","versionType":"git"},{"version":"80765597bc587feae8dbc8ce97a0f32e12a6e625","lessThan":"1fdc4164e488916402badddbb1f51e9380dabb91","status":"affected","versionType":"git"}]},{"product":"Linux","vendor":"Linux","defaultStatus":"affected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["kernel/trace/trace_events_filter.c","tools/testing/selftests/ftrace/test.d/filter/event-filter-incomplete.tc"],"versions":[{"version":"4.17","status":"affected"},{"version":"0","lessThan":"4.17","status":"unaffected","versionType":"semver"},{"version":"5.10.273","lessThanOrEqual":"5.10.*","status":"unaffected","versionType":"semver"},{"version":"5.15.224","lessThanOrEqual":"5.15.*","status":"unaffected","versionType":"semver"},{"version":"6.1.191","lessThanOrEqual":"6.1.*","status":"unaffected","versionType":"semver"},{"version":"6.6.161","lessThanOrEqual":"6.6.*","status":"unaffected","versionType":"semver"},{"version":"6.12.115","lessThanOrEqual":"6.12.*","status":"unaffected","versionType":"semver"},{"version":"6.18.60","lessThanOrEqual":"6.18.*","status":"unaffected","versionType":"semver"},{"version":"7.2.14","lessThanOrEqual":"7.2.*","status":"unaffected","versionType":"semver"},{"version":"7.3.1","lessThanOrEqual":"7.3.*","status":"unaffected","versionType":"semver"},{"version":"7.4-rc1","lessThanOrEqual":"*","status":"unaffected","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.17","versionEndExcluding":"5.10.273"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.17","versionEndExcluding":"5.15.224"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.17","versionEndExcluding":"6.1.191"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.17","versionEndExcluding":"6.6.161"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.17","versionEndExcluding":"6.12.115"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.17","versionEndExcluding":"6.18.60"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.17","versionEndExcluding":"7.2.14"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.17","versionEndExcluding":"7.3.1"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.17","versionEndExcluding":"7.4-rc1"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/4a1a6d35359991c5d47f4bf101cfbe1475c94093"},{"url":"https://git.kernel.org/stable/c/2a98f5d4913ec081e08e1075512cb7ec313d9f72"},{"url":"https://git.kernel.org/stable/c/15ff3cc7f2beecc3f95d66358f20ad7b057466aa"},{"url":"https://git.kernel.org/stable/c/b205ff58e02922ac324f931cf9eb238a3acdb048"},{"url":"https://git.kernel.org/stable/c/5a999b5a16530898f0dbe5f8c50fd45ea72e110b"},{"url":"https://git.kernel.org/stable/c/1008e9e0b8280d47f1ab5e9c113f666a023a9697"},{"url":"https://git.kernel.org/stable/c/64993d970dde2a2da353e9e99595a4fa88ec27d9"},{"url":"https://git.kernel.org/stable/c/5bcdf3c18c3471122ee9652b0e2f5cdb718d9a46"},{"url":"https://git.kernel.org/stable/c/1fdc4164e488916402badddbb1f51e9380dabb91"}],"title":"tracing: Reject incomplete event filter expressions","x_generator":{"engine":"bippy-1.2.0"}}}}