Add integer overflow checks to 6 allocation size calculations#7
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kodareef5 wants to merge 1 commit intoisc-projects:masterfrom
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Add integer overflow checks to 6 allocation size calculations#7kodareef5 wants to merge 1 commit intoisc-projects:masterfrom
kodareef5 wants to merge 1 commit intoisc-projects:masterfrom
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1. common/tree.c: Change new_len from signed int to unsigned int and add UINT_MAX/2 check before doubling. Signed int overflow in the doubling loop is undefined behavior that could cause infinite loop. 2. common/parse.c: Check universe_max > INT_MAX/2 before doubling the option space array. 3. omapip/alloc.c: Check count * sizeof(omapi_addr_t) + sizeof(list) does not overflow size_t before allocation. 4. omapip/array.c: Check (max + delta) * sizeof(char *) does not overflow size_t before array growth allocation. 5. common/options.c:3664: Check length * 4 + 3 does not overflow unsigned int in FQDN option buffer allocation. 6. common/options.c:2738: Check num_opts * 2 does not overflow int in server ORO buffer allocation.
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Six sites across five files compute allocation sizes with unchecked arithmetic that can overflow:
common/tree.c —
new_lenisint(signed) but doublesds->len(unsigned). Signed overflow is undefined behavior; a compiler may assume it never happens and optimize the loop into an infinite loop. Changed tounsigned intwithUINT_MAX/2guard.common/parse.c —
universe_max * 2can overflowintwhen the option space array grows. AddedINT_MAX/2check before doubling.omapip/alloc.c —
count * sizeof(omapi_addr_t) + sizeof(omapi_addr_list_t)can overflowsize_ton 32-bit. Added overflow check beforedmalloc.omapip/array.c —
(array->max + delta) * sizeof(char *)can overflow whenindexis nearINT_MAX. AddedSIZE_MAXcheck beforedmalloc.common/options.c:3664 —
3 + (length * 4)can overflowunsigned int. Added(UINT_MAX - 3) / 4check.common/options.c:2738 —
num_opts * 2can overflowint. AddedINT_MAX/2check.All overflow checks use the existing error handling patterns (
return 0,return ISC_R_NOMEMORY, orlog_fatal). Builds clean with-Wall -Werror.