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| author | Jeremy Allison <jra@samba.org> | 2012-04-06 14:20:12 -0700 |
|---|---|---|
| committer | Jeremy Allison <jra@samba.org> | 2012-04-06 14:20:12 -0700 |
| commit | a92c532573b293f5c0ed4a386c866bc9a3dbeef3 (patch) | |
| tree | 75fbd0f91fc7cd5b577244eaad44bacdd6f12c2e /source3/modules/vfs_default.c | |
| parent | 189b3d9b24bf553ff7096397c389f20ba99e0dfa (diff) | |
| download | samba-a92c532573b293f5c0ed4a386c866bc9a3dbeef3.tar.gz samba-a92c532573b293f5c0ed4a386c866bc9a3dbeef3.tar.bz2 samba-a92c532573b293f5c0ed4a386c866bc9a3dbeef3.zip | |
Bug found by Herb. blkcnt_t st_ex_blksize is defined as a signed value. When it is
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.
Diffstat (limited to 'source3/modules/vfs_default.c')
| -rw-r--r-- | source3/modules/vfs_default.c | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/source3/modules/vfs_default.c b/source3/modules/vfs_default.c index cf2bdb05c5..915eae67d3 100644 --- a/source3/modules/vfs_default.c +++ b/source3/modules/vfs_default.c @@ -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 |