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Fix Heap-buffer-overflow in __parse_options #1678

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Fix Heap-buffer-overflow in __parse_options #1678

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8d546b1
Fix vuln crash-7d18f37e1f05e0ff4aa4dfa2f67dd738340ad9cf
aled-ua Dec 24, 2024
e347d4d
Move the heap overflow check before the allocation
aled-ua Jan 4, 2025
6c67fb2
Terminating immediately when overflow is found
aled-ua Jan 9, 2025
6c5d27f
Fix typo err
aled-ua Jan 9, 2025
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8 changes: 7 additions & 1 deletion 3rdParty/LightPcapNg/LightPcapNg/src/light_pcapng.c
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Original file line number Diff line number Diff line change
Expand Up @@ -49,11 +49,17 @@ static struct _light_option *__parse_options(uint32_t **memory, const int32_t ma
opt->custom_option_code = *local_memory++;
opt->option_length = *local_memory++;

// Validate option_length
if (opt->option_length > max_len - 2 * sizeof(*local_memory)) {
free(opt);
return NULL;
}

actual_length = (opt->option_length % alignment) == 0 ?
opt->option_length :
(opt->option_length / alignment + 1) * alignment;

if (actual_length > 0) {
if (actual_length > 0 && actual_length <= max_len - 2 * sizeof(*local_memory)) {
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Not sure if this is enough to terminate the parsing operation.

If the actual length is out of bounds, the recursion continues.
Also remaining_size on L69 will underflow from the subtraction.

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@aled-ua aled-ua Jan 7, 2025 •
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Not sure if this is enough to terminate the parsing operation.

If the actual length is out of bounds, the recursion continues. Also remaining_size on L69 will underflow from the subtraction.

Should we terminate immediately when overflow is found? patch similar to L52.

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Yes, I think terminating immediately is better...

Also @aled-ua please use the // PCPP patch comment when making changes in LightPcapNg (you can find it in various places in LightPcapNg code), since it's a 3rd-party library and we'd like to contribute it back at some point

opt->data = calloc(1, actual_length);
memcpy(opt->data, local_memory, actual_length);
local_memory += (sizeof(**memory) / sizeof(*local_memory)) * (actual_length / alignment);
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