fix(hotbackup): bound home-path construction with snprintf#30
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db_hotbackup built the probe path with sprintf(buf, "%s/%s", home, home) into a fixed DB_MAXPATHLEN stack buffer. A -h argument longer than ~DB_MAXPATHLEN/2 overflowed buf. This is a local CLI utility run by the operator (not remotely reachable), so the impact is limited, but the unbounded write is a real defect. Use snprintf with sizeof(buf), matching the existing bounded call later in the same function. With an over-long -h the path now truncates and the subsequent path lookup fails cleanly (File name too long) instead of smashing the stack. Applied to both the canonical util/ source and the checked-in build_vxworks/ copy.
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What
db_hotbackupbuilt a probe path withsprintf(buf, "%s/%s", home, home)into a fixed
char buf[DB_MAXPATHLEN]stack buffer. A-hargument longerthan ~
DB_MAXPATHLEN/2overflowsbuf.Replace with
snprintf(buf, sizeof(buf), ...), matching the already-boundedsnprintfcall later in the same function. Applied to the canonicalutil/db_hotbackup.cand the checked-inbuild_vxworks/util/db_hotbackup.ccopy.
Impact
db_hotbackupis a local command-line utility run by the operator, not aremotely reachable surface, so the practical severity is limited (an operator
overflowing their own tool's stack). It is still a real unbounded write and
worth fixing.
Verification
make db_hotbackup, no new warnings).db_hotbackup -h <4096 'A's>now fails cleanly with"File name too long" instead of crashing; previously the
sprintfwrote~8KB into a
DB_MAXPATHLENbuffer.Note
Supersedes #23, which targeted the right line but patched only the generated
build_vxworks/copy and shipped a standalone regression test that exerciseda local
snprintfrather than the actual code path. This change fixes thecanonical source (and the vxworks copy) and verifies the real utility.