lib-index: mail-index-sync-ext - Fix offset overflow in ext header update - #303
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nishat-06 wants to merge 1 commit into
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lib-index: mail-index-sync-ext - Fix offset overflow in ext header update#303nishat-06 wants to merge 1 commit into
nishat-06 wants to merge 1 commit into
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…date offset and size come from a transaction log ext-header-update32 record and are uint32_t, so offset + size > ext->hdr_size wraps for a large offset and passes. The following buffer_write() at ext->hdr_offset + offset then writes the record data outside the extension's header area. Check offset and size separately so the comparison can't overflow.
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mail_index_sync_ext_hdr_update() checks offset + size > ext->hdr_size, but both offset and size are uint32_t read from a transaction log ext-header-update32 record, so the sum wraps for a large offset and the check passes. The buffer_write() at ext->hdr_offset + offset then also wraps and writes the record data outside the extension's own header area in hdr_copy_buf. This checks offset and size separately so the comparison can't overflow, and adds a regression test.