From: "Richard W.M. Jones" <rjones(a)redhat.com&gt; For stubs of functions that had arguments, code did this: static void mount_stub (XDR *xdr_in) { int r; struct guestfs_mount_args args; if (optargs_bitmask != 0) { //... goto done; } // possibly other tests here memset (&args, 0, sizeof args); [...] done: xdr_free ((xdrproc_t) xdr_guestfs_mount_args, (char *) &args); return; } This caused xdr_free to be called on uninitialized 'args' struct, causing a segfault. The fix is to add another label, so the code looks like: static void mount_stub (XDR *xdr_in) { int r; struct guestfs_mount_args args; if (optargs_bitmask != 0) { //... goto done_no_free; } // possibly other tests here memset (&args, 0, sizeof args); [...] done: xdr_free ((xdrproc_t) xdr_guestfs_mount_args, (char *) &args); done_no_free: return; } This fixes commit 330fbea5b2d6bd7db84f7ea7afe87cf1bcd438e0 and commit 0344248af55802bbbd816b349ec1ba9305996f6e. --- generator/generator_daemon.ml | 7 ++++--- 1 files changed, 4 insertions(+), 3 deletions(-) diff --git a/generator/generator_daemon.ml b/generator/generator_daemon.ml index 0eb2446..8c96061 100644 --- a/generator/generator_daemon.ml +++ b/generator/generator_daemon.ml @@ -136,7 +136,7 @@ and generate_daemon_actions () = pr " \"build of libguestfs. Read 'AVAILABILITY' in the guestfs(3) man page for\\n\"\n"; pr " \"how to check for the availability of features.\",\n"; pr " \"%s\");\n" group; - pr " goto done;\n"; + pr " goto done_no_free;\n"; pr " }\n"; pr "\n" | _ -> () @@ -154,14 +154,14 @@ and generate_daemon_actions () = if is_filein then pr " cancel_receive ();\n"; pr " reply_with_error (\"unknown option in optional arguments bitmask (this can happen if a program is compiled against a newer version of libguestfs, then run against an older version of the daemon)\");\n"; - pr " goto done;\n"; + pr " goto done_no_free;\n"; pr " }\n"; ) else ( pr " if (optargs_bitmask != 0) {\n"; if is_filein then pr " cancel_receive ();\n"; pr " reply_with_error (\"header optargs_bitmask field must be passed as 0 for calls that don't take optional arguments\");\n"; - pr " goto done;\n"; + pr " goto done_no_free;\n"; pr " }\n"; ); pr "\n"; @@ -339,6 +339,7 @@ and generate_daemon_actions () = pr " xdr_free ((xdrproc_t) xdr_guestfs_%s_args, (char *) &args);\n" name ); + pr "done_no_free:\n"; pr " return;\n"; pr "}\n\n"; ) daemon_functions; -- 1.7.9