[GitHub] ondra-novak opened a new issue #1895: _bulk_docs/put - damaged _rev causes uncaught exception

[GitBox <gi...@apache.org>]

ondra-novak opened a new issue #1895: _bulk_docs/put - damaged _rev causes uncaught exception
URL: https://github.com/apache/couchdb/issues/1895
 
 
   [NOTE]: # ( ^^ Provide a general summary of the issue in the title above. ^^ )
   
   Putting document with damaged _rev can cause exception returning 500 Internal Error instead of relevant error message
   
   ## Description
   
   It is possible to craft _revs by imitating replication and putting documents along with new_edits=false. However, if the _revs looks like revision generated by CouchDB, but it is somehow damaged, the couchdb crashes with exception. This also happens when _bulk_docs is used - rest of the documents are not stored and result of the execution is unknown
   
   [NOTE]: # ( Describe the problem you're encountering. )
   [TIP]:  # ( Do NOT give us access or passwords to your actual CouchDB! )
   
   ## Steps to Reproduce
   
   1. create DB "test"
   2.
   ```
   $ curl -iH "Content-Type: application/json" -d '{"docs":[{"_id":"test","aaa":"bbb","_revisions":{"start":1,"ids":["7ea7f65fbd9ddcd547969ca540fed66w"]}},{"_id":"other","_revisions":{"start":1,"ids":["aaa"]}}],"new_edits":false}' "http://localhost:5984/test/_bulk_docs"
   ```
   ```
   HTTP/1.1 500 Internal Server Error
   {"error":"unknown_error","reason":"badarg","ref":1621251896}
   ```
   
   Notice 'w' in revision of the first document. The second document is not stored.
   
   There is log record:
   
   ```
    req_err(1621251896) unknown_error : badarg
       [<<"erlang:list_to_integer/2">>,<<"couch_doc:parse_revid/1 L165">>,<<"couch_doc:-transfer_fields/3-lc$^2/1-1-/1 L280">>,<<"couch_doc:transfer_fields/3 L280">>,<<"couch_doc:from_json_obj_validate/2 L135">>,<<"chttpd_db:-db_req/2-fun-1-/1 L424">>,<<"lists:map/2 L1239">>,<<"chttpd_db:db_req/2 L423">>]
   ```
   
   When a crafted _rev is used, the request is executed correctly
   
   ```
   $ curl -iH "Content-Type: application/json" -d '{"docs":[{"_id":"test","aaa":"bbb","_revisions":{"start":1,"ids":["crafted"]}},{"_id":"other2","_revisions":{"start":1,"ids":["aaa"]}}],"new_edits":false}' "http://localhost:5984/test/_bulk_docs"
   ```
   ```
   HTTP/1.1 201 Created
   []
   ```
   
   This bug also appears, when new_edits=false is not used and the revision is damaged.
   
   ```
   $ curl -X PUT -iH  "Content-Type: application/json" -d '{"_id":"test2"}' "http://localhost:5984/test/test2"
   ```
   ```
   {"ok":true,"id":"test2","rev":"1-967a00dff5e02add41819138abb3284d"}
   ```
   ```
   $ curl -X PUT -iH  "Content-Type: application/json" -d '{"_id":"test2","_rev":"1-967a00dff5e02add41819138abb3284w"}' "http://localhost:5984/test/test2"
   ```
   ```
   {"error":"unknown_error","reason":"badarg","ref":531824669}
   ```
   
   However, if the revision is not damaged, just different, correct error message is generated
   ```
   $ curl -X PUT -iH  "Content-Type: application/json" -d '{"_id":"test2","_rev":"1-967a00dff5e02add41819138abb32841"}' "http://localhost:5984/test/test2"
   ```
   ```
   {"error":"conflict","reason":"Document update conflict."}
   ```
   
   It seems that CouchDB is trying to parse the hash part of the revision when it looks like a valid hash and it fails without handling the exception. The uncaught exception causes error 500
   
   
   [NOTE]: # ( Include commands to reproduce, if possible. curl is preferred. )
   
   ## Expected Behaviour
   
   Uncaught exception should be handled
   
   [NOTE]: # ( Tell us what you expected to happen. )
   
   ## Your Environment
   
   [TIP]:  # ( Include as many relevant details about your environment as possible. )
   [TIP]:  # ( You can paste the output of curl http://YOUR-COUCHDB:5984/ here. )
   
   * CouchDB Version used:
   
   {"couchdb":"Welcome","version":"2.3.0","git_sha":"07ea0c7","uuid":"3246e174be789358f6e0855023ea8731","features":["pluggable-storage-engines","scheduler"],"vendor":{"name":"The Apache Software Foundation"}}
   
   * Operating System and version: Ubuntu 18.04
   
   ## Additional context
   
   [TIP]:  # ( Add any other context about the problem here. )
   
   Not blocking issue, I just found this by mistake during performing tests on my project.
   

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