1. 18 1月, 2010 1 次提交
    • M
      modpost: fix segfault in sym_is() with prefixed arches · 3a5dd791
      Mike Frysinger 提交于
      The sym_is() compares a symbol in an attempt to automatically skip symbol
      prefixes.  It does this first by searching the real symbol with the normal
      unprefixed symbol.  But then it uses the length of the original symbol to
      check the end of the substring instead of the length of the symbol it is
      looking for.  On non-prefixed arches, this is effectively the same thing,
      so there is no problem.  On prefixed-arches, since this is exceeds by just
      one byte, a crash is rare and it is usually a NUL byte anyways.  But every
      once in a blue moon, you get the right page alignment and it segfaults.
      
      For example, on the Blackfin arch, sym_is() will be called with the real
      symbol "___mod_usb_device_table" as "symbol" when looking for the normal
      symbol "__mod_usb_device_table" as "name".  The substring will thus return
      one byte into "symbol" and store it into "match".  But then "match" will
      be indexed with the length of "symbol" instead of "name" and so we will
      exceed the storage.  i.e. the code ends up doing:
      	char foo[] = "abc"; return foo[strlen(foo)+1] == '\0';
      Signed-off-by: NMike Frysinger <vapier@gentoo.org>
      Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      3a5dd791
  2. 17 1月, 2010 39 次提交