fix(static): add missing enum sentinel to ngx_http_zstd_static[]#74
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The ngx_http_zstd_static[] ngx_conf_enum_t array (off/on/always) lacked
the terminating { ngx_null_string, 0 } sentinel. ngx_conf_set_enum_slot()
scans the array with `for (i = 0; e[i].name.len != 0; i++)`, so an
unmatched directive value (e.g. `zstd_static maybe;`) walks off the end
of the array reading garbage name.len/name.data — an out-of-bounds read,
and ngx_strcasecmp() then dereferences a wild pointer (possible crash /
ASAN abort). Every stock nginx enum terminates with the sentinel; add it.
With the sentinel an unknown value is a clean "invalid value" config
error instead of undefined behaviour.
Tests (t/02-conf-warn.t): TEST 3 asserts an invalid enum value is
rejected with `invalid value "maybe"` (must_die); TEST 4 asserts the
last real entry "always" still parses. The ASAN CI job runs this binary,
so a re-introduced OOB read aborts on TEST 3.
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BLOCKER from module audit.
Problem
ngx_http_zstd_static[](theoff/on/alwaysngx_conf_enum_tarray) is missing the terminating{ ngx_null_string, 0 }sentinel.ngx_conf_set_enum_slot()scans withfor (i = 0; e[i].name.len != 0; i++), so an unmatched value such aszstd_static maybe;walks off the array end — an out-of-bounds read, after whichngx_strcasecmp()dereferences a wild pointer (possible crash / ASAN abort at config load).Fix
Add the sentinel. Every stock nginx enum carries it. Unknown values now produce a clean
invalid valueconfig error.Tests
t/02-conf-warn.tTEST 3 —zstd_static maybe;->must_diewithinvalid value "maybe"(the ASAN CI job aborts here if the OOB read returns).always(last real entry) still parses/loads.Local:
prove t/02-conf-warn.t= 11/11 PASS.