lists.openwall.net   lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  linux-cve-announce  PHC 
Open Source and information security mailing list archives
 
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <20230112195542.028523143@infradead.org>
Date:   Thu, 12 Jan 2023 20:43:58 +0100
From:   Peter Zijlstra <peterz@...radead.org>
To:     peterz@...radead.org
Cc:     richard.henderson@...aro.org, ink@...assic.park.msu.ru,
        mattst88@...il.com, vgupta@...nel.org, linux@...linux.org.uk,
        nsekhar@...com, brgl@...ev.pl, ulli.kroll@...glemail.com,
        linus.walleij@...aro.org, shawnguo@...nel.org,
        Sascha Hauer <s.hauer@...gutronix.de>, kernel@...gutronix.de,
        festevam@...il.com, linux-imx@....com, tony@...mide.com,
        khilman@...nel.org, krzysztof.kozlowski@...aro.org,
        alim.akhtar@...sung.com, catalin.marinas@....com, will@...nel.org,
        guoren@...nel.org, bcain@...cinc.com, chenhuacai@...nel.org,
        kernel@...0n.name, geert@...ux-m68k.org, sammy@...my.net,
        monstr@...str.eu, tsbogend@...ha.franken.de, dinguyen@...nel.org,
        jonas@...thpole.se, stefan.kristiansson@...nalahti.fi,
        shorne@...il.com, James.Bottomley@...senPartnership.com,
        deller@....de, mpe@...erman.id.au, npiggin@...il.com,
        christophe.leroy@...roup.eu, paul.walmsley@...ive.com,
        palmer@...belt.com, aou@...s.berkeley.edu, hca@...ux.ibm.com,
        gor@...ux.ibm.com, agordeev@...ux.ibm.com,
        borntraeger@...ux.ibm.com, svens@...ux.ibm.com,
        ysato@...rs.sourceforge.jp, dalias@...c.org, davem@...emloft.net,
        richard@....at, anton.ivanov@...bridgegreys.com,
        johannes@...solutions.net, tglx@...utronix.de, mingo@...hat.com,
        bp@...en8.de, dave.hansen@...ux.intel.com, x86@...nel.org,
        hpa@...or.com, acme@...nel.org, mark.rutland@....com,
        alexander.shishkin@...ux.intel.com, jolsa@...nel.org,
        namhyung@...nel.org, jgross@...e.com, srivatsa@...il.mit.edu,
        amakhalov@...are.com, pv-drivers@...are.com,
        boris.ostrovsky@...cle.com, chris@...kel.net, jcmvbkbc@...il.com,
        rafael@...nel.org, lenb@...nel.org, pavel@....cz,
        gregkh@...uxfoundation.org, mturquette@...libre.com,
        sboyd@...nel.org, daniel.lezcano@...aro.org, lpieralisi@...nel.org,
        sudeep.holla@....com, agross@...nel.org, andersson@...nel.org,
        konrad.dybcio@...aro.org, anup@...infault.org,
        thierry.reding@...il.com, jonathanh@...dia.com,
        jacob.jun.pan@...ux.intel.com, atishp@...shpatra.org,
        Arnd Bergmann <arnd@...db.de>, yury.norov@...il.com,
        andriy.shevchenko@...ux.intel.com, linux@...musvillemoes.dk,
        dennis@...nel.org, tj@...nel.org, cl@...ux.com,
        rostedt@...dmis.org, mhiramat@...nel.org, frederic@...nel.org,
        paulmck@...nel.org, pmladek@...e.com, senozhatsky@...omium.org,
        john.ogness@...utronix.de, juri.lelli@...hat.com,
        vincent.guittot@...aro.org, dietmar.eggemann@....com,
        bsegall@...gle.com, mgorman@...e.de, bristot@...hat.com,
        vschneid@...hat.com, ryabinin.a.a@...il.com, glider@...gle.com,
        andreyknvl@...il.com, dvyukov@...gle.com,
        vincenzo.frascino@....com,
        Andrew Morton <akpm@...ux-foundation.org>, jpoimboe@...nel.org,
        linux-alpha@...r.kernel.org, linux-kernel@...r.kernel.org,
        linux-snps-arc@...ts.infradead.org, linux-omap@...r.kernel.org,
        linux-samsung-soc@...r.kernel.org, linux-csky@...r.kernel.org,
        linux-hexagon@...r.kernel.org, linux-ia64@...r.kernel.org,
        loongarch@...ts.linux.dev, linux-m68k@...ts.linux-m68k.org,
        linux-mips@...r.kernel.org, openrisc@...ts.librecores.org,
        linux-parisc@...r.kernel.org, linuxppc-dev@...ts.ozlabs.org,
        linux-riscv@...ts.infradead.org, linux-s390@...r.kernel.org,
        linux-sh@...r.kernel.org, sparclinux@...r.kernel.org,
        linux-um@...ts.infradead.org, linux-perf-users@...r.kernel.org,
        virtualization@...ts.linux-foundation.org,
        linux-xtensa@...ux-xtensa.org, linux-acpi@...r.kernel.org,
        linux-pm@...r.kernel.org, linux-clk@...r.kernel.org,
        linux-arm-msm@...r.kernel.org, linux-tegra@...r.kernel.org,
        linux-arch@...r.kernel.org, linux-mm@...ck.org,
        linux-trace-kernel@...r.kernel.org, kasan-dev@...glegroups.com,
        "Rafael J. Wysocki" <rafael.j.wysocki@...el.com>,
        Ulf Hansson <ulf.hansson@...aro.org>
Subject: [PATCH v3 44/51] entry,kasan,x86: Disallow overriding mem*() functions

KASAN cannot just hijack the mem*() functions, it needs to emit
__asan_mem*() variants if it wants instrumentation (other sanitizers
already do this).

vmlinux.o: warning: objtool: sync_regs+0x24: call to memcpy() leaves .noinstr.text section
vmlinux.o: warning: objtool: vc_switch_off_ist+0xbe: call to memcpy() leaves .noinstr.text section
vmlinux.o: warning: objtool: fixup_bad_iret+0x36: call to memset() leaves .noinstr.text section
vmlinux.o: warning: objtool: __sev_get_ghcb+0xa0: call to memcpy() leaves .noinstr.text section
vmlinux.o: warning: objtool: __sev_put_ghcb+0x35: call to memcpy() leaves .noinstr.text section

Remove the weak aliases to ensure nobody hijacks these functions and
add them to the noinstr section.

Signed-off-by: Peter Zijlstra (Intel) <peterz@...radead.org>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@...el.com>
Acked-by: Frederic Weisbecker <frederic@...nel.org>
Tested-by: Tony Lindgren <tony@...mide.com>
Tested-by: Ulf Hansson <ulf.hansson@...aro.org>
---
 arch/x86/lib/memcpy_64.S  |    5 ++---
 arch/x86/lib/memmove_64.S |    4 +++-
 arch/x86/lib/memset_64.S  |    4 +++-
 mm/kasan/kasan.h          |    4 ++++
 mm/kasan/shadow.c         |   38 ++++++++++++++++++++++++++++++++++++++
 tools/objtool/check.c     |    3 +++
 6 files changed, 53 insertions(+), 5 deletions(-)

--- a/arch/x86/lib/memcpy_64.S
+++ b/arch/x86/lib/memcpy_64.S
@@ -7,7 +7,7 @@
 #include <asm/alternative.h>
 #include <asm/export.h>
 
-.pushsection .noinstr.text, "ax"
+.section .noinstr.text, "ax"
 
 /*
  * We build a jump to memcpy_orig by default which gets NOPped out on
@@ -42,7 +42,7 @@ SYM_FUNC_START(__memcpy)
 SYM_FUNC_END(__memcpy)
 EXPORT_SYMBOL(__memcpy)
 
-SYM_FUNC_ALIAS_WEAK(memcpy, __memcpy)
+SYM_FUNC_ALIAS(memcpy, __memcpy)
 EXPORT_SYMBOL(memcpy)
 
 /*
@@ -183,4 +183,3 @@ SYM_FUNC_START_LOCAL(memcpy_orig)
 	RET
 SYM_FUNC_END(memcpy_orig)
 
-.popsection
--- a/arch/x86/lib/memmove_64.S
+++ b/arch/x86/lib/memmove_64.S
@@ -13,6 +13,8 @@
 
 #undef memmove
 
+.section .noinstr.text, "ax"
+
 /*
  * Implement memmove(). This can handle overlap between src and dst.
  *
@@ -213,5 +215,5 @@ SYM_FUNC_START(__memmove)
 SYM_FUNC_END(__memmove)
 EXPORT_SYMBOL(__memmove)
 
-SYM_FUNC_ALIAS_WEAK(memmove, __memmove)
+SYM_FUNC_ALIAS(memmove, __memmove)
 EXPORT_SYMBOL(memmove)
--- a/arch/x86/lib/memset_64.S
+++ b/arch/x86/lib/memset_64.S
@@ -6,6 +6,8 @@
 #include <asm/alternative.h>
 #include <asm/export.h>
 
+.section .noinstr.text, "ax"
+
 /*
  * ISO C memset - set a memory block to a byte value. This function uses fast
  * string to get better performance than the original function. The code is
@@ -43,7 +45,7 @@ SYM_FUNC_START(__memset)
 SYM_FUNC_END(__memset)
 EXPORT_SYMBOL(__memset)
 
-SYM_FUNC_ALIAS_WEAK(memset, __memset)
+SYM_FUNC_ALIAS(memset, __memset)
 EXPORT_SYMBOL(memset)
 
 /*
--- a/mm/kasan/kasan.h
+++ b/mm/kasan/kasan.h
@@ -551,6 +551,10 @@ void __asan_set_shadow_f3(const void *ad
 void __asan_set_shadow_f5(const void *addr, size_t size);
 void __asan_set_shadow_f8(const void *addr, size_t size);
 
+void *__asan_memset(void *addr, int c, size_t len);
+void *__asan_memmove(void *dest, const void *src, size_t len);
+void *__asan_memcpy(void *dest, const void *src, size_t len);
+
 void __hwasan_load1_noabort(unsigned long addr);
 void __hwasan_store1_noabort(unsigned long addr);
 void __hwasan_load2_noabort(unsigned long addr);
--- a/mm/kasan/shadow.c
+++ b/mm/kasan/shadow.c
@@ -38,6 +38,12 @@ bool __kasan_check_write(const volatile
 }
 EXPORT_SYMBOL(__kasan_check_write);
 
+#ifndef CONFIG_GENERIC_ENTRY
+/*
+ * CONFIG_GENERIC_ENTRY relies on compiler emitted mem*() calls to not be
+ * instrumented. KASAN enabled toolchains should emit __asan_mem*() functions
+ * for the sites they want to instrument.
+ */
 #undef memset
 void *memset(void *addr, int c, size_t len)
 {
@@ -68,6 +74,38 @@ void *memcpy(void *dest, const void *src
 
 	return __memcpy(dest, src, len);
 }
+#endif
+
+void *__asan_memset(void *addr, int c, size_t len)
+{
+	if (!kasan_check_range((unsigned long)addr, len, true, _RET_IP_))
+		return NULL;
+
+	return __memset(addr, c, len);
+}
+EXPORT_SYMBOL(__asan_memset);
+
+#ifdef __HAVE_ARCH_MEMMOVE
+void *__asan_memmove(void *dest, const void *src, size_t len)
+{
+	if (!kasan_check_range((unsigned long)src, len, false, _RET_IP_) ||
+	    !kasan_check_range((unsigned long)dest, len, true, _RET_IP_))
+		return NULL;
+
+	return __memmove(dest, src, len);
+}
+EXPORT_SYMBOL(__asan_memmove);
+#endif
+
+void *__asan_memcpy(void *dest, const void *src, size_t len)
+{
+	if (!kasan_check_range((unsigned long)src, len, false, _RET_IP_) ||
+	    !kasan_check_range((unsigned long)dest, len, true, _RET_IP_))
+		return NULL;
+
+	return __memcpy(dest, src, len);
+}
+EXPORT_SYMBOL(__asan_memcpy);
 
 void kasan_poison(const void *addr, size_t size, u8 value, bool init)
 {
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -956,6 +956,9 @@ static const char *uaccess_safe_builtin[
 	"__asan_store16_noabort",
 	"__kasan_check_read",
 	"__kasan_check_write",
+	"__asan_memset",
+	"__asan_memmove",
+	"__asan_memcpy",
 	/* KASAN in-line */
 	"__asan_report_load_n_noabort",
 	"__asan_report_load1_noabort",


Powered by blists - more mailing lists

Powered by Openwall GNU/*/Linux Powered by OpenVZ