From 83e33300a2342c5d0bf48474fdf8da22c22b4973 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Marc-Andr=C3=A9=20Lureau?= Date: Thu, 4 Jan 2018 17:05:17 +0100 Subject: crypto: fix stack-buffer-overflow error MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit ASAN complains about: ==8856==ERROR: AddressSanitizer: stack-buffer-overflow on address 0x7ffd8a1fe168 at pc 0x561136cb4451 bp 0x7ffd8a1fe130 sp 0x7ffd8a1fd8e0 READ of size 16 at 0x7ffd8a1fe168 thread T0 #0 0x561136cb4450 in __asan_memcpy (/home/elmarco/src/qq/build/tests/test-crypto-ivgen+0x110450) #1 0x561136d2a6a7 in qcrypto_ivgen_essiv_calculate /home/elmarco/src/qq/crypto/ivgen-essiv.c:83:5 #2 0x561136d29af8 in qcrypto_ivgen_calculate /home/elmarco/src/qq/crypto/ivgen.c:72:12 #3 0x561136d07c8e in test_ivgen /home/elmarco/src/qq/tests/test-crypto-ivgen.c:148:5 #4 0x7f77772c3b04 in test_case_run /home/elmarco/src/gnome/glib/builddir/../glib/gtestutils.c:2237 #5 0x7f77772c3ec4 in g_test_run_suite_internal /home/elmarco/src/gnome/glib/builddir/../glib/gtestutils.c:2321 #6 0x7f77772c3f6d in g_test_run_suite_internal /home/elmarco/src/gnome/glib/builddir/../glib/gtestutils.c:2333 #7 0x7f77772c3f6d in g_test_run_suite_internal /home/elmarco/src/gnome/glib/builddir/../glib/gtestutils.c:2333 #8 0x7f77772c3f6d in g_test_run_suite_internal /home/elmarco/src/gnome/glib/builddir/../glib/gtestutils.c:2333 #9 0x7f77772c4184 in g_test_run_suite /home/elmarco/src/gnome/glib/builddir/../glib/gtestutils.c:2408 #10 0x7f77772c2e0d in g_test_run /home/elmarco/src/gnome/glib/builddir/../glib/gtestutils.c:1674 #11 0x561136d0799b in main /home/elmarco/src/qq/tests/test-crypto-ivgen.c:173:12 #12 0x7f77756e6039 in __libc_start_main (/lib64/libc.so.6+0x21039) #13 0x561136c13d89 in _start (/home/elmarco/src/qq/build/tests/test-crypto-ivgen+0x6fd89) Address 0x7ffd8a1fe168 is located in stack of thread T0 at offset 40 in frame #0 0x561136d2a40f in qcrypto_ivgen_essiv_calculate /home/elmarco/src/qq/crypto/ivgen-essiv.c:76 This frame has 1 object(s): [32, 40) 'sector.addr' <== Memory access at offset 40 overflows this variable HINT: this may be a false positive if your program uses some custom stack unwind mechanism or swapcontext (longjmp and C++ exceptions *are* supported) SUMMARY: AddressSanitizer: stack-buffer-overflow (/home/elmarco/src/qq/build/tests/test-crypto-ivgen+0x110450) in __asan_memcpy Shadow bytes around the buggy address: 0x100031437bd0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 0x100031437be0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 0x100031437bf0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 0x100031437c00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 0x100031437c10: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 =>0x100031437c20: 00 00 00 00 00 00 00 00 f1 f1 f1 f1 00[f3]f3 f3 0x100031437c30: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 0x100031437c40: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 0x100031437c50: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 0x100031437c60: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 0x100031437c70: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 Shadow byte legend (one shadow byte represents 8 application bytes): Addressable: 00 Partially addressable: 01 02 03 04 05 06 07 Heap left redzone: fa Freed heap region: fd Stack left redzone: f1 Stack mid redzone: f2 Stack right redzone: f3 Stack after return: f5 Stack use after scope: f8 Global redzone: f9 Global init order: f6 Poisoned by user: f7 Container overflow: fc Array cookie: ac Intra object redzone: bb ASan internal: fe Left alloca redzone: ca Right alloca redzone: cb It looks like the rest of the code copes with ndata being larger than sizeof(sector), so limit the memcpy() range. Signed-off-by: Marc-AndrĂ© Lureau Reviewed-by: Daniel P. Berrange Message-Id: <20180104160523.22995-13-marcandre.lureau@redhat.com> Tested-by: Thomas Huth Reviewed-by: Thomas Huth Signed-off-by: Paolo Bonzini --- crypto/ivgen-essiv.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'crypto') diff --git a/crypto/ivgen-essiv.c b/crypto/ivgen-essiv.c index cba20bde6c..ad4d926c19 100644 --- a/crypto/ivgen-essiv.c +++ b/crypto/ivgen-essiv.c @@ -79,7 +79,7 @@ static int qcrypto_ivgen_essiv_calculate(QCryptoIVGen *ivgen, uint8_t *data = g_new(uint8_t, ndata); sector = cpu_to_le64(sector); - memcpy(data, (uint8_t *)§or, ndata); + memcpy(data, (uint8_t *)§or, MIN(sizeof(sector), ndata)); if (sizeof(sector) < ndata) { memset(data + sizeof(sector), 0, ndata - sizeof(sector)); } -- cgit v1.2.1