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authorEric Biggers <ebiggers@google.com>2017-09-24 06:59:09 -0400
committerIngo Molnar <mingo@kernel.org>2017-09-26 03:43:47 -0400
commitaf95774b3ca080b0e1e651c0fc7680f3444ddda7 (patch)
treea8a9cb7a3f2da05c49c08a7335c1f051076d879b
parentb89eda482d7849a1c146b6d0a42f4e76369bb08e (diff)
x86/fpu: Use validate_xstate_header() to validate the xstate_header in copy_kernel_to_xstate()
Tighten the checks in copy_kernel_to_xstate(). Signed-off-by: Eric Biggers <ebiggers@google.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Eric Biggers <ebiggers3@gmail.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Kees Cook <keescook@chromium.org> Cc: Kevin Hao <haokexin@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Michael Halcrow <mhalcrow@google.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Wanpeng Li <wanpeng.li@hotmail.com> Cc: Yu-cheng Yu <yu-cheng.yu@intel.com> Cc: kernel-hardening@lists.openwall.com Link: http://lkml.kernel.org/r/20170924105913.9157-7-mingo@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
-rw-r--r--arch/x86/kernel/fpu/xstate.c12
1 files changed, 2 insertions, 10 deletions
diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c
index c97c4a9db52a..325db7850335 100644
--- a/arch/x86/kernel/fpu/xstate.c
+++ b/arch/x86/kernel/fpu/xstate.c
@@ -1138,15 +1138,12 @@ int copy_xstate_to_user(void __user *ubuf, struct xregs_state *xsave, unsigned i
1138 1138
1139/* 1139/*
1140 * Convert from a ptrace standard-format kernel buffer to kernel XSAVES format 1140 * Convert from a ptrace standard-format kernel buffer to kernel XSAVES format
1141 * and copy to the target thread. This is called from xstateregs_set() and 1141 * and copy to the target thread. This is called from xstateregs_set().
1142 * there we check the CPU has XSAVES and a whole standard-sized buffer
1143 * exists.
1144 */ 1142 */
1145int copy_kernel_to_xstate(struct xregs_state *xsave, const void *kbuf) 1143int copy_kernel_to_xstate(struct xregs_state *xsave, const void *kbuf)
1146{ 1144{
1147 unsigned int offset, size; 1145 unsigned int offset, size;
1148 int i; 1146 int i;
1149 u64 allowed_features;
1150 struct xstate_header hdr; 1147 struct xstate_header hdr;
1151 1148
1152 offset = offsetof(struct xregs_state, header); 1149 offset = offsetof(struct xregs_state, header);
@@ -1154,12 +1151,7 @@ int copy_kernel_to_xstate(struct xregs_state *xsave, const void *kbuf)
1154 1151
1155 memcpy(&hdr, kbuf + offset, size); 1152 memcpy(&hdr, kbuf + offset, size);
1156 1153
1157 /* 1154 if (validate_xstate_header(&hdr))
1158 * Reject if the user sets any disabled or supervisor features:
1159 */
1160 allowed_features = xfeatures_mask & ~XFEATURE_MASK_SUPERVISOR;
1161
1162 if (hdr.xfeatures & ~allowed_features)
1163 return -EINVAL; 1155 return -EINVAL;
1164 1156
1165 for (i = 0; i < XFEATURE_MAX; i++) { 1157 for (i = 0; i < XFEATURE_MAX; i++) {