π Fix Integer Overflow Vulnerability in calloc#18
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Adds validation in `kernel/libc.in` to prevent integer overflow and negative sizes during memory allocation in `calloc`. - Asserts `n >= 0` and `size >= 0` to prevent negative values. - Explicitly handles `n == 0` or `size == 0` by returning `malloc(0)`. - Calculates `total = n * size` and checks for overflow with `total / n == size`. Co-authored-by: google-labs-jules[bot] <161369871+google-labs-jules[bot]@users.noreply.github.com>
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- Fix stray brace in kernel-root.in and remove dead thr_exit return - Add heap/obj_arena bounds checks (PRs #30, #26) - Harden malloc/calloc/realloc; replace strcpy with strlcpy; remove strcat (PRs #20, #18, #21, #28, #15) - Split nvme_pci_init, restore e1000_rx_poll, use FS_MAX_FILES constants (PRs #14, #17, #16) - Refresh context.md ponytail index after service-wrapper deletion
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Changes applied directly on main (rebased past shell.in extraction and service-wrapper deletion). Used panic() instead of unreachable()/assert() where the PRs referenced undefined helpers. |
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Merged to main in 22933b8. Changes applied directly on main (rebased past shell.in extraction and service-wrapper deletion). Used panic() instead of unreachable()/assert() where the PRs referenced undefined helpers. |
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π― What: Fixed an integer overflow vulnerability in the
callocfunction inkernel/libc.inby implementing input validation and overflow detection.norsizevalues, leading to integer overflow duringn * sizecalculation. This would result incallocallocating a buffer much smaller than requested. Subsequent operations assuming the full requested size could write past the allocated memory (heap buffer overflow).π‘οΈ Solution: The fix implements multiple layers of protection:
nandsizeare non-negative, asIntis a 64-bit signed integer.n == 0orsize == 0and returnsmalloc(0)early to prevent division by zero during the overflow check.total / n == sizeafter the multiplication to detect any overflow. If an overflow is detected, the kernel halts viapanic.PR created automatically by Jules for task 10106695328352122040 started by @undivisible