Memory Leak in directory 'src/core', file 'ngx_buf.c'

[wp02855@…]

In reviewing source code in nginx-1.15.0, it would appear that there are some memory leaks in file 'ngx_buf.c' which when functions in this file are called, the memory allocations are not released, leading to over-utilization of memory over time, the patch file is below:

@@ -21,6 +21,7 @@

b->start = ngx_palloc(pool, size);
if (b->start == NULL) {

+ ngx_free(b); /* release previous memory allocation before going home */

return NULL;

}

@@ -84,7 +85,8 @@

b = ngx_calloc_buf(pool);
if (b == NULL) {

• return NULL;

+ ngx_free(p); /* release previous memory allocation and go home */
+ return NULL; /* how do we handle previous allocations of ngx_calloc_buf()? */

}

/*

[wp02855@…]

patch file for bug reported in ticket 1914

[Shmulik Biran]

You seem to be missing the concepts of nginx memory management.
None of the tickets you just opened looks like actual leaks.
Please refer to:
​http://nginx.org/en/docs/dev/development_guide.html#pool

[Maxim Dounin]

The code in question uses allocations from a memory pool, and all allocations are freed when the pool is destroyed. There is no need to do any explicit free operations. Further, the patch tries to call ngx_free(), which is completely wrong, as this call is not memory pool aware.

Hope this helps. If you have further questions on nginx code, consider using ​mailing lists instead.

[Maxim Dounin]

See also #1915, #1916.

[Maxim Dounin]

See also #1917.

[Maxim Dounin]

See also #1918, #1919, #1920.

[Maxim Dounin]

See also #1921, #1922, #1923.