commit db89b4b1527103455e1bd85839a88d614a402354 Author: cypherpunks cypherpunks@torproject.org Date: Fri Sep 21 04:57:26 2018 +0000

rust/protover: fix null deref in protover_all_supported()

Fortunately with the current callers it couldn't happen in practice.

Fix on d1820c1516a31a149fc51a9e5126bf899e4c4e08. --- changes/bug27804 | 3 +++ src/rust/protover/ffi.rs | 3 +++ src/test/test_protover.c | 1 + 3 files changed, 7 insertions(+)

diff --git a/changes/bug27804 b/changes/bug27804 new file mode 100644 index 000000000..fa7fec0bc --- /dev/null +++ b/changes/bug27804 @@ -0,0 +1,3 @@ + o Minor bugfixes (rust): + - Fix a potential null dereference in protover_all_supported(). + Add a test for it. Fixes bug 27804; bugfix on 0.3.3.1-alpha. diff --git a/src/rust/protover/ffi.rs b/src/rust/protover/ffi.rs index 9656e8c31..ca9a504fe 100644 --- a/src/rust/protover/ffi.rs +++ b/src/rust/protover/ffi.rs @@ -68,6 +68,9 @@ pub extern "C" fn protover_all_supported(

if maybe_unsupported.is_some() { let unsupported: UnvalidatedProtoEntry = maybe_unsupported.unwrap(); + if missing_out.is_null() { + return 0; + } let c_unsupported: CString = match CString::new(unsupported.to_string()) { Ok(n) => n, Err(_) => return 1, diff --git a/src/test/test_protover.c b/src/test/test_protover.c index fb374c728..d1fc7752d 100644 --- a/src/test/test_protover.c +++ b/src/test/test_protover.c @@ -259,6 +259,7 @@ test_protover_all_supported(void *arg) tt_ptr_op(msg, OP_EQ, NULL);

// Some things we don't support + tt_assert(! protover_all_supported("Wombat=9", NULL)); tt_assert(! protover_all_supported("Wombat=9", &msg)); tt_str_op(msg, OP_EQ, "Wombat=9"); tor_free(msg);