1. 10 Apr, 2023 1 commit
    • sundb's avatar
      Use dummy allocator to make accesses defined as per standard (#11982) · e0b378d2
      sundb authored
      
      
      ## Issue
      When we use GCC-12 later or clang 9.0 later to build with `-D_FORTIFY_SOURCE=3`,
      we can see the following buffer overflow:
      ```
      === REDIS BUG REPORT START: Cut & paste starting from here ===
      6263:M 06 Apr 2023 08:59:12.915 # Redis 255.255.255 crashed by signal: 6, si_code: -6
      6263:M 06 Apr 2023 08:59:12.915 # Crashed running the instruction at: 0x7f03d59efa7c
      
      ------ STACK TRACE ------
      EIP:
      /lib/x86_64-linux-gnu/libc.so.6(pthread_kill+0x12c)[0x7f03d59efa7c]
      
      Backtrace:
      /lib/x86_64-linux-gnu/libc.so.6(+0x42520)[0x7f03d599b520]
      /lib/x86_64-linux-gnu/libc.so.6(pthread_kill+0x12c)[0x7f03d59efa7c]
      /lib/x86_64-linux-gnu/libc.so.6(raise+0x16)[0x7f03d599b476]
      /lib/x86_64-linux-gnu/libc.so.6(abort+0xd3)[0x7f03d59817f3]
      /lib/x86_64-linux-gnu/libc.so.6(+0x896f6)[0x7f03d59e26f6]
      /lib/x86_64-linux-gnu/libc.so.6(__fortify_fail+0x2a)[0x7f03d5a8f76a]
      /lib/x86_64-linux-gnu/libc.so.6(+0x1350c6)[0x7f03d5a8e0c6]
      src/redis-server 127.0.0.1:25111(+0xd5e80)[0x557cddd3be80]
      src/redis-server 127.0.0.1:25111(feedReplicationBufferWithObject+0x78)[0x557cddd3c768]
      src/redis-server 127.0.0.1:25111(replicationFeedSlaves+0x1a4)[0x557cddd3cbc4]
      src/redis-server 127.0.0.1:25111(+0x8721a)[0x557cddced21a]
      src/redis-server 127.0.0.1:25111(call+0x47a)[0x557cddcf38ea]
      src/redis-server 127.0.0.1:25111(processCommand+0xbf4)[0x557cddcf4aa4]
      src/redis-server 127.0.0.1:25111(processInputBuffer+0xe6)[0x557cddd22216]
      src/redis-server 127.0.0.1:25111(readQueryFromClient+0x3a8)[0x557cddd22898]
      src/redis-server 127.0.0.1:25111(+0x1b9134)[0x557cdde1f134]
      src/redis-server 127.0.0.1:25111(aeMain+0x119)[0x557cddce5349]
      src/redis-server 127.0.0.1:25111(main+0x466)[0x557cddcd6716]
      /lib/x86_64-linux-gnu/libc.so.6(+0x29d90)[0x7f03d5982d90]
      /lib/x86_64-linux-gnu/libc.so.6(__libc_start_main+0x80)[0x7f03d5982e40]
      src/redis-server 127.0.0.1:25111(_start+0x25)[0x557cddcd7025]
      ```
      
      The main reason is that when FORTIFY_SOURCE is enabled, GCC or clang will enhance some
      common functions, such as `strcpy`, `memcpy`, `fgets`, etc, so that they can detect buffer
      overflow errors and stop program execution, thus improving the safety of the program.
      We use `zmalloc_usable_size()` everywhere to use memory blocks, but that is an abuse since the
      malloc_usable_size() isn't meant for this kind of use, it is for diagnostics only. That is also why the
      behavior is flaky when built with _FORTIFY_SOURCE, the compiler can sense that we reach outside
      the allocated block and SIGABRT.
      
      ### Solution
      If we need to use the additional memory we got, we need to use a dummy realloc with `alloc_size` attribute
      and no inlining, (see `extend_to_usable`) to let the compiler see the large of memory we need to use.
      This can either be an implicit call inside `z*usable` that returns the size, so that the caller doesn't have any
      other worry, or it can be a normal zmalloc call which means that if the caller wants to use
      zmalloc_usable_size it must also use extend_to_usable.
      
      ### Changes
      
      This PR does the following:
      1) rename the current z[try]malloc_usable family to z[try]malloc_internal and don't expose them to users outside zmalloc.c,
      2) expose a new set of `z[*]_usable` family that use z[*]_internal and `extend_to_usable()` implicitly, the caller gets the
        size of the allocation and it is safe to use.
      3) go over all the users of `zmalloc_usable_size` and convert them to use the `z[*]_usable` family if possible.
      4) in the places where the caller can't use `z[*]_usable` and store the real size, and must still rely on zmalloc_usable_size,
        we still make sure that the allocation used `z[*]_usable` (which has a call to `extend_to_usable()`) and ignores the
        returning size, this way a later call to `zmalloc_usable_size` is still safe.
      
      [4] was done for module.c and listpack.c, all the others places (sds, reply proto list, replication backlog, client->buf)
      are using [3].
      Co-authored-by: default avatarOran Agra <oran@redislabs.com>
      e0b378d2
  2. 16 Feb, 2021 1 commit
  3. 01 Dec, 2017 2 commits
  4. 27 Mar, 2017 1 commit
  5. 25 Jul, 2015 1 commit
  6. 08 Nov, 2012 1 commit
  7. 01 Jul, 2010 1 commit
    • antirez's avatar
      redis.c split into many different C files. · e2641e09
      antirez authored
      networking related stuff moved into networking.c
      
      moved more code
      
      more work on layout of source code
      
      SDS instantaneuos memory saving. By Pieter and Salvatore at VMware ;)
      
      cleanly compiling again after the first split, now splitting it in more C files
      
      moving more things around... work in progress
      
      split replication code
      
      splitting more
      
      Sets split
      
      Hash split
      
      replication split
      
      even more splitting
      
      more splitting
      
      minor change
      e2641e09
  8. 19 Feb, 2010 1 commit
  9. 28 May, 2009 1 commit
  10. 19 May, 2009 2 commits