libnetcdf 4.4.1.1 crashes on netcdf v4 files with attributes of type string

[rouault]

From ​https://trac.osgeo.org/gdal/ticket/7172

There is a crash specific to the latest netcdf version in OSGeo4W (4.4.1.1), but cannot be reproduced with the previous one (4.3.0). It is also specific of netcdf v4 files that have at least one attribute of type "string"

Given test.c

#include <netcdf.h>

int main(int argc, char* argv[])
{
    int cdfid = -1;
    nc_open(argv[1], NC_NOWRITE, &cdfid);
    nc_close(cdfid);
    return 0;
}

compiled with "cl minimal.c /Ie:\osgeo4W64\include e:\OSGeo4W64\lib\netcdf.lib" (with VS 2015 64bit) and minimal.nc (attached) being a netcdf 4 file with just a variable of type string

$ ncdump /tmp/minimum.nc
netcdf minimum {

// global attributes:
		string :Conventions = "CF-1.6" ;
}

"minimum.exe minimal.nc" crashes. DrMemory output is

Error #1: INVALID HEAP ARGUMENT to free 0x00000000029c2830
# 0 replace_free                              [d:\drmemory_package\common\alloc_replace.c:2706]
# 1 hdf5.dll!H5Aexists                       +0xf8     (0x000007fef3219b59 <hdf5.dll+0x9b59>)
# 2 hdf5.dll!H5I_dec_ref                     +0xaf     (0x000007fef339f600 <hdf5.dll+0x18f600>)
# 3 netcdf.dll!nc_set_var_chunk_cache_ints   +0x9695   (0x000007feee823f86 <netcdf.dll+0x43f86>)
# 4 netcdf.dll!NC4_sync                      +0xb9d    (0x000007feee814a2e <netcdf.dll+0x34a2e>)
# 5 netcdf.dll!nc_set_var_chunk_cache_ints   +0x215    (0x000007feee81ab06 <netcdf.dll+0x3ab06>)
# 6 netcdf.dll!cdRel2Iso                     +0x41d    (0x000007feee7f073e <netcdf.dll+0x1073e>)
# 7 netcdf.dll!nc_set_var_chunk_cache_ints   +0x146b   (0x000007feee81bd5c <netcdf.dll+0x3bd5c>)
# 8 netcdf.dll!nc_set_var_chunk_cache_ints   +0xe99    (0x000007feee81b78a <netcdf.dll+0x3b78a>)
# 9 netcdf.dll!NC4_sync                      +0xab     (0x000007feee813f3c <netcdf.dll+0x33f3c>)
#10 netcdf.dll!NC4_close                     +0x3c     (0x000007feee813aed <netcdf.dll+0x33aed>)
#11 netcdf.dll!nc_close                      +0x23     (0x000007feee7e2994 <netcdf.dll+0x2994>)
#12 minimal.exe!?                            +0x0      (0x000000013f32103c <minimal.exe+0x103c>)
#13 minimal.exe!?                            +0x0      (0x000000013f321255 <minimal.exe+0x1255>)
#14 KERNEL32.dll!BaseThreadInitThunk         +0xc      (0x0000000077a3652d <KERNEL32.dll+0x1652d>)
Note: @0:00:00.491 in thread 3780
Note: refers to -7 byte(s) beyond last valid byte in prior malloc
Note: prev lower malloc:  0x00000000029c2830-0x00000000029c2837

[sabb]

See also: ​https://issues.qgis.org/issues/21162

[jef]

Fixed by updating szip, hdf4, hdf5 and netcdf using VC14.