C++ error: Free() invalid next size (fast) - c++

Question

I just have a 10 line c++ program and it throws a half page error when I run it.
This is the following program
void getDataset(double ** f, int nRows, int nAttribute){
ifstream u;
u.open("iris.txt");
for(int i = 0; i < nRows; i++)
for(int j = 0; j < nAttribute; j++)
u >> f[i][j];
}
int main(){
int nRows = 150, nAttribute = 4, k = 3;
double * mat[nRows];
for(int i = 0; i < nRows; i++){
mat[i] = new double(nAttribute);
}
mat[149][3] = 2;
getDataset(mat, nRows, nAttribute);
cout << mat[100][2] << endl;
}
I tried to copy the error using ./a.out > error.log but its not working. The error.log is empty. So I had to copy paste it here, directly.
*** glibc detected *** ./a.out: free(): invalid next size (fast): 0x0000000000ef1520 ***
======= Backtrace: =========
/lib/x86_64-linux-gnu/libc.so.6(+0x7e846)[0x7f8ba675b846]
/usr/lib/x86_64-linux-gnu/libstdc++.so.6(_ZNSsD1Ev+0x23)[0x7f8ba704cc13]
/usr/lib/x86_64-linux-gnu/libstdc++.so.6(_ZNKSt7num_getIcSt19istreambuf_iteratorIcSt11char_traitsIcEEE6do_getES3_S3_RSt8ios_baseRSt12_Ios_IostateRd+0xf5)[0x7f8ba703cb25]
/usr/lib/x86_64-linux-gnu/libstdc++.so.6(_ZNSi10_M_extractIdEERSiRT_+0x8f)[0x7f8ba702d22f]
./a.out[0x40170c]
./a.out[0x40186f]
/lib/x86_64-linux-gnu/libc.so.6(__libc_start_main+0xed)[0x7f8ba66fe76d]
./a.out[0x400aa9]
======= Memory map: ========
00400000-00402000 r-xp 00000000 08:06 524669 /home/aditya/Documents/a.out
00601000-00602000 r--p 00001000 08:06 524669 /home/aditya/Documents/a.out
00602000-00603000 rw-p 00002000 08:06 524669 /home/aditya/Documents/a.out
00eee000-00f0f000 rw-p 00000000 00:00 0 [heap]
7f8ba66dd000-7f8ba6892000 r-xp 00000000 08:06 1447163 /lib/x86_64-linux-gnu/libc-2.15.so
7f8ba6892000-7f8ba6a91000 ---p 001b5000 08:06 1447163 /lib/x86_64-linux-gnu/libc-2.15.so
7f8ba6a91000-7f8ba6a95000 r--p 001b4000 08:06 1447163 /lib/x86_64-linux-gnu/libc-2.15.so
7f8ba6a95000-7f8ba6a97000 rw-p 001b8000 08:06 1447163 /lib/x86_64-linux-gnu/libc-2.15.so
7f8ba6a97000-7f8ba6a9c000 rw-p 00000000 00:00 0
7f8ba6a9c000-7f8ba6ab1000 r-xp 00000000 08:06 1440108 /lib/x86_64-linux-gnu/libgcc_s.so.1
7f8ba6ab1000-7f8ba6cb0000 ---p 00015000 08:06 1440108 /lib/x86_64-linux-gnu/libgcc_s.so.1
7f8ba6cb0000-7f8ba6cb1000 r--p 00014000 08:06 1440108 /lib/x86_64-linux-gnu/libgcc_s.so.1
7f8ba6cb1000-7f8ba6cb2000 rw-p 00015000 08:06 1440108 /lib/x86_64-linux-gnu/libgcc_s.so.1
7f8ba6cb2000-7f8ba6dad000 r-xp 00000000 08:06 1447283 /lib/x86_64-linux-gnu/libm-2.15.so
7f8ba6dad000-7f8ba6fac000 ---p 000fb000 08:06 1447283 /lib/x86_64-linux-gnu/libm-2.15.so
7f8ba6fac000-7f8ba6fad000 r--p 000fa000 08:06 1447283 /lib/x86_64-linux-gnu/libm-2.15.so
7f8ba6fad000-7f8ba6fae000 rw-p 000fb000 08:06 1447283 /lib/x86_64-linux-gnu/libm-2.15.so
7f8ba6fae000-7f8ba7090000 r-xp 00000000 08:06 400528 /usr/lib/x86_64-linux-gnu/libstdc++.so.6.0.16
7f8ba7090000-7f8ba728f000 ---p 000e2000 08:06 400528 /usr/lib/x86_64-linux-gnu/libstdc++.so.6.0.16
7f8ba728f000-7f8ba7297000 r--p 000e1000 08:06 400528 /usr/lib/x86_64-linux-gnu/libstdc++.so.6.0.16
7f8ba7297000-7f8ba7299000 rw-p 000e9000 08:06 400528 /usr/lib/x86_64-linux-gnu/libstdc++.so.6.0.16
7f8ba7299000-7f8ba72ae000 rw-p 00000000 00:00 0
7f8ba72ae000-7f8ba72d0000 r-xp 00000000 08:06 1447286 /lib/x86_64-linux-gnu/ld-2.15.so
7f8ba74b3000-7f8ba74b8000 rw-p 00000000 00:00 0
7f8ba74cd000-7f8ba74d0000 rw-p 00000000 00:00 0
7f8ba74d0000-7f8ba74d1000 r--p 00022000 08:06 1447286 /lib/x86_64-linux-gnu/ld-2.15.so
7f8ba74d1000-7f8ba74d3000 rw-p 00023000 08:06 1447286 /lib/x86_64-linux-gnu/ld-2.15.so
7fff6ef55000-7fff6ef76000 rw-p 00000000 00:00 0 [stack]
7fff6ef8c000-7fff6ef8d000 r-xp 00000000 00:00 0 [vdso]
ffffffffff600000-ffffffffff601000 r-xp 00000000 00:00 0 [vsyscall]
Aborted

Answer 1

You are not allocating a double array with new double(nAttribute). Your code needs to change to new double[ nAttribute ].