Commit Graph

5 Commits

Author SHA1 Message Date
Oran Agra
cfb449cc80
Sanitize dump payload: excessive free on dup zset fields (#8189) 2020-12-14 17:10:31 +02:00
Oran Agra
7ca00d694d Sanitize dump payload: fail RESTORE if memory allocation fails
When RDB input attempts to make a huge memory allocation that fails,
RESTORE should fail gracefully rather than die with panic
2020-12-06 14:54:34 +02:00
Oran Agra
3716950cfc Sanitize dump payload: validate no duplicate records in hash/zset/intset
If RESTORE passes successfully with full sanitization, we can't affort
to crash later on assertion due to duplicate records in a hash when
converting it form ziplist to dict.
This means that when doing full sanitization, we must make sure there
are no duplicate records in any of the collections.
2020-12-06 14:54:34 +02:00
Oran Agra
c31055db61 Sanitize dump payload: fuzz tester and fixes for segfaults and leaks it exposed
The test creates keys with various encodings, DUMP them, corrupt the payload
and RESTORES it.
It utilizes the recently added use-exit-on-panic config to distinguish between
 asserts and segfaults.
If the restore succeeds, it runs random commands on the key to attempt to
trigger a crash.

It runs in two modes, one with deep sanitation enabled and one without.
In the first one we don't expect any assertions or segfaults, in the second one
we expect assertions, but no segfaults.
We also check for leaks and invalid reads using valgrind, and if we find them
we print the commands that lead to that issue.

Changes in the code (other than the test):
- Replace a few NPD (null pointer deference) flows and division by zero with an
  assertion, so that it doesn't fail the test. (since we set the server to use
  `exit` rather than `abort` on assertion).
- Fix quite a lot of flows in rdb.c that could have lead to memory leaks in
  RESTORE command (since it now responds with an error rather than panic)
- Add a DEBUG flag for SET-SKIP-CHECKSUM-VALIDATION so that the test don't need
  to bother with faking a valid checksum
- Remove a pile of code in serverLogObjectDebugInfo which is actually unsafe to
  run in the crash report (see comments in the code)
- fix a missing boundary check in lzf_decompress

test suite infra improvements:
- be able to run valgrind checks before the process terminates
- rotate log files when restarting servers
2020-12-06 14:54:34 +02:00
Oran Agra
ca1c182567 Sanitize dump payload: ziplist, listpack, zipmap, intset, stream
When loading an encoded payload we will at least do a shallow validation to
check that the size that's encoded in the payload matches the size of the
allocation.
This let's us later use this encoded size to make sure the various offsets
inside encoded payload don't reach outside the allocation, if they do, we'll
assert/panic, but at least we won't segfault or smear memory.

We can also do 'deep' validation which runs on all the records of the encoded
payload and validates that they don't contain invalid offsets. This lets us
detect corruptions early and reject a RESTORE command rather than accepting
it and asserting (crashing) later when accessing that payload via some command.

configuration:
- adding ACL flag skip-sanitize-payload
- adding config sanitize-dump-payload [yes/no/clients]

For now, we don't have a good way to ensure MIGRATE in cluster resharding isn't
being slowed down by these sanitation, so i'm setting the default value to `no`,
but later on it should be set to `clients` by default.

changes:
- changing rdbReportError not to `exit` in RESTORE command
- adding a new stat to be able to later check if cluster MIGRATE isn't being
  slowed down by sanitation.
2020-12-06 14:54:34 +02:00