[New-bugs-announce] [issue36262] Coverity scan: Python/dtoa.c resource leak

[Charalampos Stratakis]

New submission from Charalampos Stratakis <cstratak at redhat.com>:

Coverity report on dtoa.c. It was run on python2 but the same code resides on python3.

Error: RESOURCE_LEAK (CWE-772): [#def89]
Python-2.7.15/Python/dtoa.c:1846: alloc_fn: Storage is returned from allocation function "s2b".
Python-2.7.15/Python/dtoa.c:526:9: alloc_fn: Storage is returned from allocation function "multadd".
Python-2.7.15/Python/dtoa.c:479:13: alloc_fn: Storage is returned from allocation function "Balloc".
Python-2.7.15/Python/dtoa.c:371:13: alloc_fn: Storage is returned from allocation function "PyMem_Malloc".
Python-2.7.15/Objects/object.c:2348:5: alloc_fn: Storage is returned from allocation function "malloc".
Python-2.7.15/Objects/object.c:2348:5: return_alloc_fn: Directly returning storage allocated by "malloc".
Python-2.7.15/Python/dtoa.c:371:13: var_assign: Assigning: "rv" = "PyMem_Malloc(len * 8UL)".
Python-2.7.15/Python/dtoa.c:379:5: return_alloc: Returning allocated memory "rv".
Python-2.7.15/Python/dtoa.c:479:13: var_assign: Assigning: "b1" = "Balloc(b->k + 1)".
Python-2.7.15/Python/dtoa.c:486:13: var_assign: Assigning: "b" = "b1".
Python-2.7.15/Python/dtoa.c:491:5: return_alloc: Returning allocated memory "b".
Python-2.7.15/Python/dtoa.c:526:9: var_assign: Assigning: "b" = "multadd(b, 10, *s++ - 48)".
Python-2.7.15/Python/dtoa.c:530:5: return_alloc: Returning allocated memory "b".
Python-2.7.15/Python/dtoa.c:1846: var_assign: Assigning: "bd0" = storage returned from "s2b(s0, nd0, nd, y)".
Python-2.7.15/Python/dtoa.c:2249: leaked_storage: Variable "bd0" going out of scope leaks the storage it points to.
 2247|   
 2248|     undfl:
 2249|->     return sign ? -0.0 : 0.0;
 2250|   
 2251|     ovfl:

Error: RESOURCE_LEAK (CWE-772): [#def90]
Python-2.7.15/Python/dtoa.c:2006: alloc_fn: Storage is returned from allocation function "diff".
Python-2.7.15/Python/dtoa.c:952:5: alloc_fn: Storage is returned from allocation function "Balloc".
Python-2.7.15/Python/dtoa.c:371:13: alloc_fn: Storage is returned from allocation function "PyMem_Malloc".
Python-2.7.15/Objects/object.c:2348:5: alloc_fn: Storage is returned from allocation function "malloc".
Python-2.7.15/Objects/object.c:2348:5: return_alloc_fn: Directly returning storage allocated by "malloc".
Python-2.7.15/Python/dtoa.c:371:13: var_assign: Assigning: "rv" = "PyMem_Malloc(len * 8UL)".
Python-2.7.15/Python/dtoa.c:379:5: return_alloc: Returning allocated memory "rv".
Python-2.7.15/Python/dtoa.c:952:5: var_assign: Assigning: "c" = "Balloc(a->k)".
Python-2.7.15/Python/dtoa.c:962:5: var_assign: Assigning: "xc" = "c".
Python-2.7.15/Python/dtoa.c:996:5: return_alloc: Returning allocated memory "c".
Python-2.7.15/Python/dtoa.c:2006: var_assign: Assigning: "delta" = storage returned from "diff(bb, bd)".
Python-2.7.15/Python/dtoa.c:2016: noescape: Resource "delta" is not freed or pointed-to in "cmp".
Python-2.7.15/Python/dtoa.c:890:13: noescape: "cmp(Bigint *, Bigint *)" does not free or save its parameter "a".
Python-2.7.15/Python/dtoa.c:2129: noescape: Resource "delta" is not freed or pointed-to in "ratio".
Python-2.7.15/Python/dtoa.c:1179:15: noescape: "ratio(Bigint *, Bigint *)" does not free or save its parameter "a".
Python-2.7.15/Python/dtoa.c:2249: leaked_storage: Variable "delta" going out of scope leaks the storage it points to.
 2247|   
 2248|     undfl:
 2249|->     return sign ? -0.0 : 0.0;
 2250|   
 2251|     ovfl:

----------
components: Interpreter Core
messages: 337668
nosy: cstratak
priority: normal
severity: normal
status: open
title: Coverity scan: Python/dtoa.c resource leak
versions: Python 2.7, Python 3.7, Python 3.8

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Python tracker <report at bugs.python.org>
<https://bugs.python.org/issue36262>
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