Klaus Demo nginx / 455bd72
Range filter: protect from total size overflows. The overflow can be used to circumvent the restriction on total size of ranges introduced in c2a91088b0c0 (1.1.2). Additionally, overflow allows producing ranges with negative start (such ranges can be created by using a suffix, "bytes=-100"; normally this results in 200 due to the total size check). These can result in the following errors in logs: [crit] ... pread() ... failed (22: Invalid argument) [alert] ... sendfile() failed (22: Invalid argument) When using cache, it can be also used to reveal cache file header. It is believed that there are no other negative effects, at least with standard nginx modules. In theory, this can also result in memory disclosure and/or segmentation faults if multiple ranges are allowed, and the response is returned in a single in-memory buffer. This never happens with standard nginx modules though, as well as known 3rd party modules. Fix is to properly protect from possible overflow when incrementing size. Maxim Dounin 2 years ago
1 changed file(s) with 4 addition(s) and 0 deletion(s). Raw diff Collapse all Expand all
376376 range->start = start;
377377 range->end = end;
378378
379 if (size > NGX_MAX_OFF_T_VALUE - (end - start)) {
380 return NGX_HTTP_RANGE_NOT_SATISFIABLE;
381 }
382
379383 size += end - start;
380384
381385 if (ranges-- == 0) {