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| author | Joseph Myers <joseph@codesourcery.com> | 2016-11-08 23:44:51 +0000 |
|---|---|---|
| committer | Joseph Myers <joseph@codesourcery.com> | 2016-11-08 23:44:51 +0000 |
| commit | 5874510faaf3cbd0bb112aaacab9f225002beed1 (patch) | |
| tree | 715525d323256065690c763c09b88bd11ba52a72 /sunrpc/Makefile | |
| parent | 116ae4fe5a70d99cf06088f0222a5913996f7f70 (diff) | |
| download | glibc-5874510faaf3cbd0bb112aaacab9f225002beed1.tar.gz | |
Fix rpcgen buffer overrun (bug 20790).
Building with GCC 7 produces an error building rpcgen:
rpc_parse.c: In function 'get_prog_declaration':
rpc_parse.c:543:25: error: may write a terminating nul past the end of the destination [-Werror=format-length=]
sprintf (name, "%s%d", ARGNAME, num); /* default name of argument */
~~~~^
rpc_parse.c:543:5: note: format output between 5 and 14 bytes into a destination of size 10
sprintf (name, "%s%d", ARGNAME, num); /* default name of argument */
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
That buffer overrun is for the case where the .x file declares a
program with a million arguments. The strcpy two lines above can
generate a buffer overrun much more simply for a long argument name.
The limit on length of line read by rpcgen (MAXLINESIZE == 1024)
provides a bound on the buffer size needed, so this patch just changes
the buffer size to MAXLINESIZE to avoid both possible buffer
overruns. A testcase is added that rpcgen does not crash with a
500-character argument name, where it previously crashed.
It would not at all surprise me if there are many other ways of
crashing rpcgen with either valid or invalid input; fuzz testing would
likely find various such bugs, though I don't think they are that
important to fix (rpcgen is not that likely to be used with untrusted
.x files as input). (As well as fuzz-findable bugs there are probably
also issues when various int variables get overflowed on very large
input.) The test infrastructure for rpcgen-not-crashing tests would
need extending if tests are to be added for cases where rpcgen should
produce an error, as opposed to cases where it should succeed.
Tested for x86_64 and x86.
[BZ #20790]
* sunrpc/rpc_parse.c (get_prog_declaration): Increase buffer size
to MAXLINESIZE.
* sunrpc/bug20790.x: New file.
* sunrpc/Makefile [$(run-built-tests) = yes] (rpcgen-tests): New
variable.
[$(run-built-tests) = yes] (tests-special): Add $(rpcgen-tests).
[$(run-built-tests) = yes] ($(rpcgen-tests)): New rule.
Diffstat (limited to 'sunrpc/Makefile')
| -rw-r--r-- | sunrpc/Makefile | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/sunrpc/Makefile b/sunrpc/Makefile index 789ef423e5..99e5c3ccf8 100644 --- a/sunrpc/Makefile +++ b/sunrpc/Makefile @@ -103,6 +103,11 @@ ifeq ($(have-thread-library),yes) xtests += thrsvc endif +ifeq ($(run-built-tests),yes) +rpcgen-tests := $(objpfx)bug20790.out +tests-special += $(rpcgen-tests) +endif + headers += $(rpcsvc:%.x=rpcsvc/%.h) extra-libs := librpcsvc extra-libs-others := librpcsvc # Make it in `others' pass, not `lib' pass. @@ -225,3 +230,9 @@ endif endif $(objpfx)thrsvc: $(common-objpfx)linkobj/libc.so $(shared-thread-library) + +ifeq ($(run-built-tests),yes) +$(rpcgen-tests): $(objpfx)%.out: %.x $(objpfx)rpcgen + $(built-program-cmd) -c $< -o $@; \ + $(evaluate-test) +endif |