GCC static analyzer warnings

[Allen Winter]

Milan

sorry for the super-long delay.
your patch has been committed into the 3.0 and master branches.


On Monday, April 19, 2021 3:07:01 AM EDT Milan Crha wrote:
> 	Hello,
> I just received a list of static analyzer warnings reported by GCC. I
> won't say it's anything urgent, thus no problem it "missed" the 3.0.10
> release. The warnings are at the end of this message. My comments on
> them:
> 
> Those from src/libicalvcal/vobject.c can eventually happen, when the
> machine is out of memory. I do not see a way to pass the out-of-memory
> situation to the caller here (I know libical does it on some other
> places).
> 
> The src/libicalss/icalsslexer.c is a generated file by flex.
> 
> The memory leak at src/libicalss/icalcalendar.c:105 is valid. See the
> attached patch.
> 
> The double frees at src/libical/icalmime.c:248 and
> src/libical/icallangbind.c:263 are false positives, from my point of
> view.
> 
> 	Bye,
> 	Milan
> 
> 1. Defect type: GCC_ANALYZER_WARNING 
> 1. libical-3.0.9/src/libicalvcal/vobject.c:1471:8: warning[-Wanalyzer-possible-null-dereference]: dereference of possibly-NULL 't'
> #  1469|           u++; t++;
> #  1470|           }
> #  1471|->     *t = 0;
> #  1472|       return s;
> #  1473|   }
> 
> 2. Defect type: GCC_ANALYZER_WARNING
> 1. libical-3.0.9/src/libicalvcal/vobject.c:1468:16: warning[-Wanalyzer-possible-null-dereference]: dereference of possibly-NULL 't'
> #  1466|               *t = '\r';
> #  1467|           else
> #  1468|->             *t = (char)*u;
> #  1469|           u++; t++;
> #  1470|           }
> 
> 3. Defect type: GCC_ANALYZER_WARNING
> 1. libical-3.0.9/src/libicalvcal/vobject.c:1466:16: warning[-Wanalyzer-possible-null-dereference]: dereference of possibly-NULL 't'
> #  1464|               *t = '\n';
> #  1465|           else if (*u == (wchar_t)0x2029)
> #  1466|->             *t = '\r';
> #  1467|           else
> #  1468|               *t = (char)*u;
> 
> 4. Defect type: GCC_ANALYZER_WARNING
> 1. libical-3.0.9/src/libicalss/icalsslexer.c:0: scope_hint: In function 'ss_scan_buffer'
> 2. libical-3.0.9/src/libicalss/icalsslexer.c:1742:32: warning[-Wanalyzer-malloc-leak]: leak of '<unknown>'
> #  1740|                   buf[i] = yybytes[i];
> #  1741|   
> #  1742|->         buf[_yybytes_len] = buf[_yybytes_len+1] = YY_END_OF_BUFFER_CHAR;
> #  1743|   
> #  1744|           b = ss_scan_buffer(buf,n );
> 
> 5. Defect type: GCC_ANALYZER_WARNING
> 1. libical-3.0.9/src/libicalss/icalsslexer.c:0: scope_hint: In function 'sspush_buffer_state'
> 2. libical-3.0.9/src/libicalss/icalsslexer.c:1597:34: warning[-Wanalyzer-malloc-leak]: leak of '<unknown>'
> 17. libical-3.0.9/src/libicalss/icalsslexer.c:1585:14: note: in expansion of macro 'YY_CURRENT_BUFFER'
> 20. libical-3.0.9/src/libicalss/icalsslexer.c:1594:13: note: in expansion of macro 'YY_CURRENT_BUFFER'
> #  1595|                   (yy_buffer_stack_top)++;
> #  1596|           /* coverity[var_deref_op] */
> #  1597|->         YY_CURRENT_BUFFER_LVALUE = new_buffer;
> #  1598|   
> #  1599|           /* copied from ss_switch_to_buffer. */
> 
> 6. Defect type: GCC_ANALYZER_WARNING
> 1. libical-3.0.9/src/libicalss/icalcalendar.c:105:9: warning[-Wanalyzer-malloc-leak]: leak of '<unknown>'
> 3. libical-3.0.9/src/libicalss/icalset.h:40: included_from: Included from here.
> 4. libical-3.0.9/src/libicalss/icalcalendar.h:26: included_from: Included from here.
> 5. libical-3.0.9/src/libicalss/icalcalendar.c:23: included_from: Included from here.
> 7. libical-3.0.9/src/libicalss/icalcalendar.c:90:5: note: in expansion of macro 'icalerror_check_arg_rz'
> 19. libical-3.0.9/src/libicalss/icalset.h:40: included_from: Included from here.
> 20. libical-3.0.9/src/libicalss/icalcalendar.h:26: included_from: Included from here.
> 21. libical-3.0.9/src/libicalss/icalcalendar.c:23: included_from: Included from here.
> 23. libical-3.0.9/src/libicalss/icalcalendar.c:64:5: note: in expansion of macro 'icalerror_check_arg_re'
> #   103|   
> #   104|       if (icalcalendar_create(impl) != ICAL_NO_ERROR) {
> #   105|->         free(impl);
> #   106|           return 0;
> #   107|       }
> 
> 7. Defect type: GCC_ANALYZER_WARNING
> 1. libical-3.0.9/src/libical/icalmime.c:0: scope_hint: In function 'icalmime_parse'
> 2. libical-3.0.9/src/libical/icalmime.c:248:13: warning[-Wanalyzer-double-free]: double-'free' of 'mimeTypeCopy'
> 24. libical-3.0.9/src/libical/icalerror.h:25: included_from: Included from here.
> 25. libical-3.0.9/src/libical/icalmime.c:26: included_from: Included from here.
> #   246|                   comp,
> #   247|                   icalproperty_new_xlicmimecontenttype(mimeTypeCopy));
> #   248|->             free(mimeTypeCopy);
> #   249|           }
> #   250|   
> 
> 8. Defect type: GCC_ANALYZER_WARNING
> 1. libical-3.0.9/src/libical/icallangbind.c:263:9: warning[-Wanalyzer-double-free]: double-'free' of 'copy'
> #   261|           APPENDS(v);
> #   262|           APPENDC('\'');
> #   263|->         free(copy);
> #   264|       }
> #   265|   
> 
>