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Message-ID: <164461681510.16921.7342982385624280943.tip-bot2@tip-bot2>
Date: Fri, 11 Feb 2022 22:00:15 -0000
From: "tip-bot2 for Reinette Chatre" <tip-bot2@...utronix.de>
To: linux-tip-commits@...r.kernel.org
Cc: Reinette Chatre <reinette.chatre@...el.com>,
Dave Hansen <dave.hansen@...ux.intel.com>,
Shuah Khan <skhan@...uxfoundation.org>, x86@...nel.org,
linux-kernel@...r.kernel.org
Subject: [tip: x86/sgx] selftests/sgx: Fix NULL-pointer-dereference upon early
test failure
The following commit has been merged into the x86/sgx branch of tip:
Commit-ID: 2d03861e0d1d1ee81efc59338101cdd86a7474f6
Gitweb: https://git.kernel.org/tip/2d03861e0d1d1ee81efc59338101cdd86a7474f6
Author: Reinette Chatre <reinette.chatre@...el.com>
AuthorDate: Tue, 08 Feb 2022 13:48:39 -08:00
Committer: Dave Hansen <dave.hansen@...ux.intel.com>
CommitterDate: Fri, 11 Feb 2022 13:52:47 -08:00
selftests/sgx: Fix NULL-pointer-dereference upon early test failure
== Background ==
The SGX selftests track parts of the enclave binaries in an array:
encl->segment_tbl[]. That array is dynamically allocated early
(but not first) in the test's lifetime. The array is referenced
at the end of the test in encl_delete().
== Problem ==
encl->segment_tbl[] can be NULL if the test fails before its
allocation. That leads to a NULL-pointer-dereference in encl_delete().
This is triggered during early failures of the selftest like if the
enclave binary ("test_encl.elf") is deleted.
== Solution ==
Ensure encl->segment_tbl[] is valid before attempting to access
its members. The offset with which it is accessed, encl->nr_segments,
is initialized before encl->segment_tbl[] and thus considered valid
to use after the encl->segment_tbl[] check succeeds.
Fixes: 3200505d4de6 ("selftests/sgx: Create a heap for the test enclave")
Signed-off-by: Reinette Chatre <reinette.chatre@...el.com>
Signed-off-by: Dave Hansen <dave.hansen@...ux.intel.com>
Acked-by: Shuah Khan <skhan@...uxfoundation.org>
Link: https://lkml.kernel.org/r/90a31dfd640ea756fa324712e7cbab4a90fa7518.1644355600.git.reinette.chatre@intel.com
---
tools/testing/selftests/sgx/load.c | 9 +++++----
1 file changed, 5 insertions(+), 4 deletions(-)
diff --git a/tools/testing/selftests/sgx/load.c b/tools/testing/selftests/sgx/load.c
index 9d4322c..006b464 100644
--- a/tools/testing/selftests/sgx/load.c
+++ b/tools/testing/selftests/sgx/load.c
@@ -21,7 +21,7 @@
void encl_delete(struct encl *encl)
{
- struct encl_segment *heap_seg = &encl->segment_tbl[encl->nr_segments - 1];
+ struct encl_segment *heap_seg;
if (encl->encl_base)
munmap((void *)encl->encl_base, encl->encl_size);
@@ -32,10 +32,11 @@ void encl_delete(struct encl *encl)
if (encl->fd)
close(encl->fd);
- munmap(heap_seg->src, heap_seg->size);
-
- if (encl->segment_tbl)
+ if (encl->segment_tbl) {
+ heap_seg = &encl->segment_tbl[encl->nr_segments - 1];
+ munmap(heap_seg->src, heap_seg->size);
free(encl->segment_tbl);
+ }
memset(encl, 0, sizeof(*encl));
}
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