https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108400
Bug ID: 108400
Summary: false positive: null dereference
Product: gcc
Version: 13.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: analyzer
Assignee: dmalcolm at gcc dot gnu.org
Reporter: chipitsine at gmail dot com
Target Milestone: ---
bug is reproduced on the following gcc version:
commit f54e3b3ba01ced7ecda3caed51b42f707d489c77 (HEAD -> master, origin/trunk,
origin/master, origin/HEAD)
Author: Alexandre Oliva <ol...@adacore.com>
Date: Thu Jan 12 00:29:33 2023 -0300
repro steps:
git clone --recursive https://github.com/SoftEtherVPN/SoftEtherVPN
cd SoftEtherVPN
export CC=/home/ilia/gcc/gcc-home/bin/gcc
export CFLAGS="-fanalyzer"
cmake .
make
I've reviewed the following finding, which I beleive is false positive
/home/ilia/SoftEtherVPN/src/Cedar/WebUI.c: In function ‘WuExpireSessionKey’:
/home/ilia/SoftEtherVPN/src/Cedar/WebUI.c:1871:29: warning: dereference of NULL
‘0’ [CWE-476] [-Wanalyzer-null-dereference]
1871 | WU_CONTEXT *context = (WU_CONTEXT*)entry->Value;
| ^~~~~~~
‘WuExpireSessionKey’: event 1
|
| 1868 | for(i=0; i<LIST_NUM(wu->Contexts); i++)
|
‘WuExpireSessionKey’: event 2
|
| 1870 | STRMAP_ENTRY *entry =
(STRMAP_ENTRY*)LIST_DATA(wu->Contexts, i);
|
‘WuExpireSessionKey’: event 3
|
| 1870 | STRMAP_ENTRY *entry =
(STRMAP_ENTRY*)LIST_DATA(wu->Contexts, i);
|
‘WuExpireSessionKey’: event 4
|
|/home/ilia/SoftEtherVPN/src/./Mayaqua/Memory.h:116:54:
| 116 | #define LIST_DATA(o, i) (((o) != NULL) ? ((o)->p[(i)]) :
NULL)
| | ~~~^~~
| | |
| | (4) ...to
here
/home/ilia/SoftEtherVPN/src/Cedar/WebUI.c:1870:54: note: in expansion of macro
‘LIST_DATA’
| 1870 | STRMAP_ENTRY *entry =
(STRMAP_ENTRY*)LIST_DATA(wu->Contexts, i);
| | ^~~~~~~~~
|
‘WuExpireSessionKey’: event 5
|
| 1868 | for(i=0; i<LIST_NUM(wu->Contexts); i++)
|
‘WuExpireSessionKey’: events 6-7
|
| 1870 | STRMAP_ENTRY *entry =
(STRMAP_ENTRY*)LIST_DATA(wu->Contexts, i);
| 1871 | WU_CONTEXT *context = (WU_CONTEXT*)entry->Value;
| | ~~~~~~~
| | |
| | (7) dereference of NULL ‘<unknown>’
|
WU_CONTEXT *context = (WU_CONTEXT*)entry->Value; - it is variable definition,
there's no dereference.
