15/17: gnu: guile-ssh: Fix potential double-free/use-after-free issue.

[Ludovic Courtès]

civodul pushed a commit to branch version-0.13.0
in repository guix.

commit c383dc520f4b71bcb99115768bfafa00df85f9d1
Author: Ludovic Courtès <address@hidden>
Date:   Fri May 19 10:50:20 2017 +0200

    gnu: guile-ssh: Fix potential double-free/use-after-free issue.
    
    Fixes <http://bugs.gnu.org/26976>.
    Reported by Mark H Weaver <address@hidden>.
    
    * gnu/packages/patches/guile-ssh-double-free.patch: New file.
    * gnu/local.mk (dist_patch_DATA): Add it.
    * gnu/packages/ssh.scm (guile-ssh)[source](patches): Add it.
---
 gnu/local.mk                                     |  1 +
 gnu/packages/patches/guile-ssh-double-free.patch | 37 ++++++++++++++++++++++++
 gnu/packages/ssh.scm                             |  3 +-
 3 files changed, 40 insertions(+), 1 deletion(-)

diff --git a/gnu/local.mk b/gnu/local.mk
index ca26bcd..f1a3cf6 100644
--- a/gnu/local.mk
+++ b/gnu/local.mk
@@ -651,6 +651,7 @@ dist_patch_DATA =                                           
\
   %D%/packages/patches/guile-relocatable.patch                 \
   %D%/packages/patches/guile-rsvg-pkgconfig.patch              \
   %D%/packages/patches/guile-ssh-rexec-bug.patch               \
+  %D%/packages/patches/guile-ssh-double-free.patch             \
   %D%/packages/patches/gtk2-respect-GUIX_GTK2_PATH.patch       \
   %D%/packages/patches/gtk2-respect-GUIX_GTK2_IM_MODULE_FILE.patch \
   %D%/packages/patches/gtk2-theme-paths.patch                  \
diff --git a/gnu/packages/patches/guile-ssh-double-free.patch 
b/gnu/packages/patches/guile-ssh-double-free.patch
new file mode 100644
index 0000000..9692b81
--- /dev/null
+++ b/gnu/packages/patches/guile-ssh-double-free.patch
@@ -0,0 +1,37 @@
+Fix a double-free or use-after-free issue with Guile-SSH used
+with Guile 2.2.  See <https://bugs.gnu.org/26976>.
+
+diff --git a/libguile-ssh/channel-type.c b/libguile-ssh/channel-type.c
+index 3dd641f..0839854 100644
+--- a/libguile-ssh/channel-type.c
++++ b/libguile-ssh/channel-type.c
+@@ -229,10 +229,11 @@ ptob_close (SCM channel)
+       ssh_channel_free (ch->ssh_channel);
+     }
+ 
++  SCM_SETSTREAM (channel, NULL);
++
+ #if USING_GUILE_BEFORE_2_2
+   scm_gc_free (pt->write_buf, pt->write_buf_size, "port write buffer");
+   scm_gc_free (pt->read_buf,  pt->read_buf_size, "port read buffer");
+-  SCM_SETSTREAM (channel, NULL);
+ 
+   return 0;
+ #endif
+diff --git a/libguile-ssh/sftp-file-type.c b/libguile-ssh/sftp-file-type.c
+index 8879924..f87cf03 100644
+--- a/libguile-ssh/sftp-file-type.c
++++ b/libguile-ssh/sftp-file-type.c
+@@ -224,10 +224,11 @@ ptob_close (SCM sftp_file)
+       sftp_close (fd->file);
+     }
+ 
++  SCM_SETSTREAM (sftp_file, NULL);
++
+ #if USING_GUILE_BEFORE_2_2
+   scm_gc_free (pt->write_buf, pt->write_buf_size, "port write buffer");
+   scm_gc_free (pt->read_buf,  pt->read_buf_size, "port read buffer");
+-  SCM_SETSTREAM (sftp_file, NULL);
+ 
+   return 1;
+ #endif
diff --git a/gnu/packages/ssh.scm b/gnu/packages/ssh.scm
index 6a074d1..bb18987 100644
--- a/gnu/packages/ssh.scm
+++ b/gnu/packages/ssh.scm
@@ -226,7 +226,8 @@ Additionally, various channel-specific options can be 
negotiated.")
               (sha256
                (base32
                 "0r261i8kc3avbmbwgyzak2vnqwssjlgz37g2y2fwm80w9bmn2m7j"))
-              (patches (search-patches "guile-ssh-rexec-bug.patch"))
+              (patches (search-patches "guile-ssh-rexec-bug.patch"
+                                       "guile-ssh-double-free.patch"))
               (modules '((guix build utils)))
               (snippet
                ;; 'configure.ac' mistakenly tries to link files from examples/