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Bug found by Herb. blkcnt_t st_ex_blksize is defined as a signed value. When it is

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on a 32-bit system and defined as a long, then inside vfswrap_get_alloc_size()
we cast to a uint64_t. This sign-extends when converting to unsigned,
so if the high bit of st_ex_blksize is set we return insane values to clients.
This commit is contained in:
Jeremy Allison 2012-04-06 14:20:12 -07:00
parent 189b3d9b24
commit a92c532573
3 changed files with 53 additions and 0 deletions
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26
source3/configure.in
View File

@ -2936,6 +2936,32 @@ fi
AC_CHECK_TYPES([blksize_t, blkcnt_t], [], [], [[#include <sys/stat.h>]])
AC_CACHE_CHECK([for 32 bit blkcnt_t],samba_cv_SIZEOF_BLKCNT_T_4,[
AC_TRY_RUN([
#if defined(HAVE_UNISTD_H)
#include <unistd.h>
#endif
#include <stdio.h>
#include <sys/stat.h>
main() { exit((sizeof(blkcnt_t) == 4) ? 0 : 1); }],
samba_cv_SIZEOF_BLKCNT_T_4=yes,samba_cv_SIZEOF_BLKCNT_T_4=no,samba_cv_SIZEOF_BLKCNT_T_4=cross)])
if test x"$samba_cv_SIZEOF_BLKCNT_T_4" = x"yes"; then
AC_DEFINE(SIZEOF_BLKCNT_T_4,1,[The size of the 'blkcnt_t' type])
fi
AC_CACHE_CHECK([for 64 bit blkcnt_t],samba_cv_SIZEOF_BLKCNT_T_8,[
AC_TRY_RUN([
#if defined(HAVE_UNISTD_H)
#include <unistd.h>
#endif
#include <stdio.h>
#include <sys/stat.h>
main() { exit((sizeof(blkcnt_t) == 8) ? 0 : 1); }],
samba_cv_SIZEOF_BLKCNT_T_8=yes,samba_cv_SIZEOF_BLKCNT_T_8=no,samba_cv_SIZEOF_BLKCNT_T_8=cross)])
if test x"$samba_cv_SIZEOF_BLKCNT_T_8" = x"yes"; then
AC_DEFINE(SIZEOF_BLKCNT_T_8,1,[The size of the 'blkcnt_t' type])
fi
AC_CACHE_CHECK([for st_blksize in struct stat],samba_cv_HAVE_STAT_ST_BLKSIZE,[
AC_TRY_COMPILE([#include <sys/types.h>
#include <sys/stat.h>

13
source3/modules/vfs_default.c
View File

@ -1119,7 +1119,20 @@ static uint64_t vfswrap_get_alloc_size(vfs_handle_struct *handle,
}
#if defined(HAVE_STAT_ST_BLOCKS) && defined(STAT_ST_BLOCKSIZE)
/* The type of st_blocksize is blkcnt_t which *MUST* be
signed (according to POSIX) and can be less than 64-bits.
Ensure when we're converting to 64 bits wide we don't
sign extend. */
#if defined(SIZEOF_BLKCNT_T_8)
result = (uint64_t)STAT_ST_BLOCKSIZE * (uint64_t)sbuf->st_ex_blocks;
#elif defined(SIZEOF_BLKCNT_T_4)
{
uint64_t bs = ((uint64_t)sbuf->st_ex_blocks) & 0xFFFFFFFFLL;
result = (uint64_t)STAT_ST_BLOCKSIZE * bs;
}
#else
#error SIZEOF_BLKCNT_T_NOT_A_SUPPORTED_VALUE
#endif
#else
result = get_file_size_stat(sbuf);
#endif

14
source3/wscript
View File

@ -174,6 +174,20 @@ main() {
conf.CHECK_STRUCTURE_MEMBER('struct stat', 'st_flags', define='HAVE_STAT_ST_FLAGS',
headers='sys/types.h sys/stat.h unistd.h')
if "HAVE_BLKCNT_T" in conf.env:
conf.CHECK_CODE('''
return sizeof(blkcnt_t) == 4 ? 0 : 1''',
'SIZEOF_BLKCNT_T_4', execute=True,
headers='sys/types.h sys/stat.h unistd.h',
msg="Checking whether blkcnt_t is 32 bit")
if "HAVE_BLKCNT_T" in conf.env:
conf.CHECK_CODE('''
return sizeof(blkcnt_t) == 8 ? 0 : 1''',
'SIZEOF_BLKCNT_T_8', execute=True,
headers='sys/types.h sys/stat.h unistd.h',
msg="Checking whether blkcnt_t is 64 bit")
# Check for POSIX capability support
conf.CHECK_FUNCS_IN('cap_get_proc', 'cap', headers='sys/capability.h')