Use memcpy to copy correctly even for unaligned memory. This was already done for some functions here, but not all.
Also took the oppurtunity to remove a bunch of seemingly obsolete/commented code.
gcc11 made assumptions about optimization based on strict aliasing rules
that led to this code malfunction, which was caught by the test suite.
gcc printed out a warning whose meaning was not immediately obvious:
ncx.c: In function 'ncx_putn_float_schar':
ncx.c:272:20: warning: 'xx' may be used uninitialized [-Wmaybe-uninitialized]
272 | uint32_t tmp = *(uint32_t*)src;
| ^~~~~~~~~~~~~~~
ncx.c:3512:14: note: 'xx' was declared here
3512 | ix_float xx = NC_FILL_FLOAT;
| ^~
Due to optimization and inlining, the initialization of this variable was
lost.
Signed-off-by: Egbert Eich <eich@suse.com>
https://github.com/Unidata/netcdf-c/issues/1168https://github.com/Unidata/netcdf-c/issues/1163https://github.com/Unidata/netcdf-c/issues/1162
This PR partially fixes memory leaks in the netcdf-c library,
in the ncdump utility, and in some test cases.
The netcdf-c library now runs memory clean with the assumption
that the --disable-utilities option is used. The primary remaining
problem is ncgen. Once that is fixed, I believe the netcdf-c library
will run memory clean with no limitations.
Notes
-----------
1. Memory checking was performed using gcc -fsanitize=address.
Valgrind-based testing has yet to be performed.
2. The pnetcdf, hdf4, and examples code has not been tested.
Misc. Non-leak changes
1. Make tst_diskless2 only run when netcdf4 is enabled (issue 1162)
2. Fix CmakeLists.txt to turn off logging if ENABLE_NETCDF_4 is OFF
3. Isolated all my debug scripts into a single top-level directory
called debug
4. Fix some USE_NETCDF4 dependencies in nc_test and nc_test4 Makefile.am
Getting the value of the x variable on the file corresponding to the below ncdump output
with -fsanitize=undefined raises
ncx.c:1034:14: runtime error: left shift of 128 by 24 places cannot be represented in type 'int'
This is due to *cp being promoted to int before doing the left shift, instead
of the intended unsigned. So do the cast to unsigned internally rather than
externally
ncdump file to reproduce:
netcdf temp {
dimensions:
x = 2 ;
y = 2 ;
v = 2 ;
variables:
int x(v) ;
byte y(y, x) ;
data:
x = _, _ ;
y =
-127, -127,
-127, -127 ;
}
Fixes https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=2356
Credit to OSS Fuzz
Running a build on the .nc file corresponding to the below ncdump output
with -fsanitize=undefined raises
libsrc/ncx.c:4722:26: runtime error: left shift of 255 by 24 places cannot be represented in type 'int'
This is due to *cp being promoted to int before doing the left shift, instead
of the intended unsigned. So do the cast to unsigned internally rather than
externally
ncdump file to reproduce:
netcdf temp {
dimensions:
y = UNLIMITED ; // (0 currently)
x = 109067 ;
variables:
byte t(y, x, x) ;
data:
}
Fixes https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=2265
Credit to OSS Fuzz
