[Bug analyzer/106003] New: RFE: -fanalyzer could complain about misuse of file-descriptors

[Bug analyzer/106003] New: RFE: -fanalyzer could complain about misuse of file-descriptors

[dmalcolm at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106003

            Bug ID: 106003
           Summary: RFE: -fanalyzer could complain about misuse of
                    file-descriptors
           Product: gcc
           Version: 12.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: analyzer
          Assignee: dmalcolm at gcc dot gnu.org
          Reporter: dmalcolm at gcc dot gnu.org
  Target Milestone: ---

-fanalyzer could be extended to check POSIX file-descriptor APIs ("int" rather
than FILE *).

e.g.
- check for FD leaks
- check for double "close" of a FD (CWE-1341, I believe)
- check for read/write of a closed descriptor
- check for read/write of a descriptor opened for just writing/reading
etc

Immad Mir is looking at this for GSoC 2022.

Example of a "double file-descriptor close" bug:
  http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2019-13351
albeit in C++.

[Bug analyzer/106003] RFE: -fanalyzer could complain about misuse of file-descriptors

[dmalcolm at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106003

--- Comment #1 from David Malcolm <dmalcolm at gcc dot gnu.org> ---
See also this mailing list thread:
  https://gcc.gnu.org/pipermail/gcc/2022-June/238801.html

[Bug analyzer/106003] RFE: -fanalyzer could complain about misuse of file-descriptors

[mir at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106003

Immad Mir <mir at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Last reconfirmed|                            |2022-06-19
             Status|UNCONFIRMED                 |ASSIGNED
     Ever confirmed|0                           |1

[Bug analyzer/106003] RFE: -fanalyzer could complain about misuse of file-descriptors

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106003

--- Comment #2 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Immad Mir <mir@gcc.gnu.org>:

https://gcc.gnu.org/g:97baacba963c06e3d0e33cde04e7e687671e60e7

commit r13-1404-g97baacba963c06e3d0e33cde04e7e687671e60e7
Author: Immad Mir <mirimmad17@gmail.com>
Date:   Sat Jul 2 22:09:37 2022 +0530

    analyzer: implement five new warnings for misuse of POSIX file descriptor
APIs [PR106003].

    This patch adds a new state machine to the analyzer for checking usage of
POSIX file descriptor
    APIs with five new warnings.

    It adds:
    - check for FD leaks (CWE 775).
    - check for double "close" of a FD (CWE-1341).
    - check for read/write of a closed file descriptor.
    - check whether a file descriptor was used without being checked for
validity.
    - check for read/write of a descriptor opened for just writing/reading.

    gcc/ChangeLog:
            PR analyzer/106003
            * Makefile.in (ANALYZER_OBJS): Add sm-fd.o.
            * doc/invoke.texi:  Add -Wanalyzer-fd-double-close,
-Wanalyzer-fd-leak,
            -Wanalyzer-fd-access-mode-mismatch,
-Wanalyzer-fd-use-without-check,
            -Wanalyzer-fd-use-after-close.

    gcc/analyzer/ChangeLog:
            PR analyzer/106003
            * analyzer.opt (Wanalyzer-fd-leak): New option.
            (Wanalyzer-fd-access-mode-mismatch): New option.
            (Wanalyzer-fd-use-without-check): New option.
            (Wanalyzer-fd-double-close): New option.
            (Wanalyzer-fd-use-after-close): New option.
            * sm.h (make_fd_state_machine): New decl.
            * sm.cc (make_checkers): Call make_fd_state_machine.
            * sm-fd.cc: New file.

    gcc/testsuite/ChangeLog:
            PR analyzer/106003
            * gcc.dg/analyzer/fd-1.c: New test.
            * gcc.dg/analyzer/fd-2.c: New test.
            * gcc.dg/analyzer/fd-3.c: New test.
            * gcc.dg/analyzer/fd-4.c: New test.

[Bug analyzer/106003] RFE: -fanalyzer could complain about misuse of file-descriptors

[marxin at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106003

Martin Liška <marxin at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |marxin at gcc dot gnu.org

--- Comment #3 from Martin Liška <marxin at gcc dot gnu.org> ---
Hello Immad.

I noticed you pushed the git change, but it violates the GNU coding style in
some aspects. I see usage of Windows newlines, 8 spaces are not replaced with
tabular and there's one minor issue:
/home/marxin/BIG/buildbot/buildworker/marxinbox-gcc-clang/build/gcc/analyzer/sm-fd.cc:545:7:
warning: field 'm_invalid' will be initialized after field 'm_valid_read_write'
[-Wreorder-ctor]

Moreover, I noticed the patch hasn't been sent to gcc-patches mailing list.
Please do so next time before you commit a patch.

[Bug analyzer/106003] RFE: -fanalyzer could complain about misuse of file-descriptors

[marxin at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106003

Martin Liška <marxin at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           See Also|                            |https://gcc.gnu.org/bugzill
                   |                            |a/show_bug.cgi?id=106184

--- Comment #4 from Martin Liška <marxin at gcc dot gnu.org> ---
> /home/marxin/BIG/buildbot/buildworker/marxinbox-gcc-clang/build/gcc/analyzer/
> sm-fd.cc:545:7: warning: field 'm_invalid' will be initialized after field
> 'm_valid_read_write' [-Wreorder-ctor]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106184

[Bug analyzer/106003] RFE: -fanalyzer could complain about misuse of file-descriptors

[mir at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106003

--- Comment #5 from Immad Mir <mir at gcc dot gnu.org> ---
Thanks for bringing that to my attention. I will make the suggested corrections
in a follow-up patch.

[Bug analyzer/106003] RFE: -fanalyzer could complain about misuse of file-descriptors

[dmalcolm at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106003

--- Comment #6 from David Malcolm <dmalcolm at gcc dot gnu.org> ---
I don't think we were tracking the RFE for this in bugzilla, so just a note
that Immad had now committed his patch for the three new attributes for
functions that make use of file descriptors:
https://gcc.gnu.org/git/?p=gcc.git;a=commitdiff;h=f8e6e2c046e1015697356ee7079fb39e0cb6add5

I've also added a link to this to https://gcc.gnu.org/wiki/StaticAnalyzer

Thanks Immad

[Bug analyzer/106003] RFE: -fanalyzer could complain about misuse of file-descriptors

[mir at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106003
Bug 106003 depends on bug 106286, which changed state.

Bug 106286 Summary: fd_diagnostic should implement get_meaning_for_state_change vfunc
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106286

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |RESOLVED
         Resolution|---                         |FIXED

[Bug analyzer/106003] RFE: -fanalyzer could complain about misuse of file-descriptors

[mir at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106003
Bug 106003 depends on bug 106298, which changed state.

Bug 106298 Summary: RFE: analyzer handling of dup, dup2, and dup3
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106298

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|ASSIGNED                    |RESOLVED
         Resolution|---                         |FIXED

[Bug analyzer/106003] RFE: -fanalyzer could complain about misuse of file-descriptors

[dmalcolm at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106003
Bug 106003 depends on bug 106300, which changed state.

Bug 106300 Summary: RFE: analyzer support for more ways of obtaining an open file descriptor
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106300

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |RESOLVED
         Resolution|---                         |FIXED

[Bug analyzer/106003] RFE: -fanalyzer could complain about misuse of file-descriptors

[dmalcolm at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106003
Bug 106003 depends on bug 107486, which changed state.

Bug 107486 Summary: [13 Regression] ICE when pipe's argument is not a pointer type
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107486

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|ASSIGNED                    |RESOLVED
         Resolution|---                         |FIXED

[Bug analyzer/106003] RFE: -fanalyzer could complain about misuse of file-descriptors

[dmalcolm at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106003
Bug 106003 depends on bug 106302, which changed state.

Bug 106302 Summary: RFE: provide a way for -fanalyzer to use target flags
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106302

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|WAITING                     |RESOLVED
         Resolution|---                         |FIXED

[Bug analyzer/106003] RFE: -fanalyzer could complain about misuse of file-descriptors

[dmalcolm at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106003
Bug 106003 depends on bug 106140, which changed state.

Bug 106140 Summary: RFE: analyzer could complain about misuses of socket APIs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106140

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|WAITING                     |RESOLVED
         Resolution|---                         |FIXED

[Bug analyzer/106003] RFE: -fanalyzer could complain about misuse of file-descriptors

[dmalcolm at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106003

--- Comment #7 from David Malcolm <dmalcolm at gcc dot gnu.org> ---
For reference, this article (by one of my colleagues) talks about how valgrind
can detect file descriptor leaks *dynamically*:
 
https://developers.redhat.com/articles/2023/01/09/how-use-valgrind-track-file-descriptors#