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authorJoseph Myers <joseph@codesourcery.com>2016-11-08 23:44:51 +0000
committerJoseph Myers <joseph@codesourcery.com>2016-11-08 23:44:51 +0000
commit5874510faaf3cbd0bb112aaacab9f225002beed1 (patch)
tree715525d323256065690c763c09b88bd11ba52a72 /sunrpc
parent116ae4fe5a70d99cf06088f0222a5913996f7f70 (diff)
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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] ($(rpcgen-tests)): New rule.
Diffstat (limited to 'sunrpc')
-rw-r--r--sunrpc/Makefile11
-rw-r--r--sunrpc/bug20790.x1
-rw-r--r--sunrpc/rpc_parse.c2
3 files changed, 13 insertions, 1 deletions
diff --git a/sunrpc/Makefile b/sunrpc/Makefile
index 789ef42..99e5c3c 100644
--- a/sunrpc/Makefile
+++ b/sunrpc/Makefile
@@ -103,6 +103,11 @@ ifeq ($(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
diff --git a/sunrpc/bug20790.x b/sunrpc/bug20790.x
new file mode 100644
index 0000000..a00c9b3
--- /dev/null
+++ b/sunrpc/bug20790.x
@@ -0,0 +1 @@
+program TPROG { version TVERS { int FUNC(int aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa) = 1; } = 1; } = 1;
diff --git a/sunrpc/rpc_parse.c b/sunrpc/rpc_parse.c
index 1a1df6d..505a655 100644
--- a/sunrpc/rpc_parse.c
+++ b/sunrpc/rpc_parse.c
@@ -521,7 +521,7 @@ static void
get_prog_declaration (declaration * dec, defkind dkind, int num /* arg number */ )
{
token tok;
- char name[10]; /* argument name */
+ char name[MAXLINESIZE]; /* argument name */
if (dkind == DEF_PROGRAM)
{