4.9-stable patches

added patches:
	x86-uaccess-don-t-leak-the-ac-flag-into-__put_user-value-evaluation.patch

diff --git a/queue-4.9/series b/queue-4.9/series
index 87d2eca0e076308d7ea11994f4a11dfaa690b852..a59fbef3132ed564f721db243031f1af2f1dbfc9 100644 (file)
--- a/queue-4.9/series
+++ b/queue-4.9/series
@@ -29,3 +29,4 @@ kvm-nsvm-clear-events-pending-from-svm_complete_inte.patch
 powerpc-always-initialize-input-array-when-calling-epapr_hypercall.patch
 mmc-spi-fix-card-detection-during-probe.patch
 mm-enforce-min-addr-even-if-capable-in-expand_downwards.patch
+x86-uaccess-don-t-leak-the-ac-flag-into-__put_user-value-evaluation.patch

diff --git a/queue-4.9/x86-uaccess-don-t-leak-the-ac-flag-into-__put_user-value-evaluation.patch b/queue-4.9/x86-uaccess-don-t-leak-the-ac-flag-into-__put_user-value-evaluation.patch
new file mode 100644 (file)
index 0000000..b8e1336
--- /dev/null
+++ b/queue-4.9/x86-uaccess-don-t-leak-the-ac-flag-into-__put_user-value-evaluation.patch
@@ -0,0 +1,62 @@
+From 2a418cf3f5f1caf911af288e978d61c9844b0695 Mon Sep 17 00:00:00 2001
+From: Andy Lutomirski <luto@kernel.org>
+Date: Fri, 22 Feb 2019 17:17:04 -0800
+Subject: x86/uaccess: Don't leak the AC flag into __put_user() value evaluation
+
+From: Andy Lutomirski <luto@kernel.org>
+
+commit 2a418cf3f5f1caf911af288e978d61c9844b0695 upstream.
+
+When calling __put_user(foo(), ptr), the __put_user() macro would call
+foo() in between __uaccess_begin() and __uaccess_end().  If that code
+were buggy, then those bugs would be run without SMAP protection.
+
+Fortunately, there seem to be few instances of the problem in the
+kernel. Nevertheless, __put_user() should be fixed to avoid doing this.
+Therefore, evaluate __put_user()'s argument before setting AC.
+
+This issue was noticed when an objtool hack by Peter Zijlstra complained
+about genregs_get() and I compared the assembly output to the C source.
+
+ [ bp: Massage commit message and fixed up whitespace. ]
+
+Fixes: 11f1a4b9755f ("x86: reorganize SMAP handling in user space accesses")
+Signed-off-by: Andy Lutomirski <luto@kernel.org>
+Signed-off-by: Borislav Petkov <bp@suse.de>
+Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
+Cc: Peter Zijlstra <peterz@infradead.org>
+Cc: Brian Gerst <brgerst@gmail.com>
+Cc: Josh Poimboeuf <jpoimboe@redhat.com>
+Cc: Denys Vlasenko <dvlasenk@redhat.com>
+Cc: stable@vger.kernel.org
+Link: http://lkml.kernel.org/r/20190225125231.845656645@infradead.org
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+---
+ arch/x86/include/asm/uaccess.h |    7 ++++---
+ 1 file changed, 4 insertions(+), 3 deletions(-)
+
+--- a/arch/x86/include/asm/uaccess.h
++++ b/arch/x86/include/asm/uaccess.h
+@@ -292,8 +292,7 @@ do {                                                                       \
+               __put_user_asm(x, ptr, retval, "l", "k", "ir", errret); \
+               break;                                                  \
+       case 8:                                                         \
+-              __put_user_asm_u64((__typeof__(*ptr))(x), ptr, retval,  \
+-                                 errret);                             \
++              __put_user_asm_u64(x, ptr, retval, errret);             \
+               break;                                                  \
+       default:                                                        \
+               __put_user_bad();                                       \
+@@ -427,8 +426,10 @@ do {                                                                      \
+ #define __put_user_nocheck(x, ptr, size)                      \
+ ({                                                            \
+       int __pu_err;                                           \
++      __typeof__(*(ptr)) __pu_val;                            \
++      __pu_val = x;                                           \
+       __uaccess_begin();                                      \
+-      __put_user_size((x), (ptr), (size), __pu_err, -EFAULT); \
++      __put_user_size(__pu_val, (ptr), (size), __pu_err, -EFAULT);\
+       __uaccess_end();                                        \
+       __builtin_expect(__pu_err, 0);                          \
+ })