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authorLinus Torvalds <torvalds@linux-foundation.org>2018-11-01 11:46:27 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2018-11-01 11:46:27 -0700
commit2d6bb6adb714b133db92ccd4bfc9c20f75f71f3f (patch)
treeaef040a1ee4b8b6edc5a4fa2b3c6a2c48219f27a /arch/x86/entry/entry_64.S
parent7c6c54b505b8aea1782ce6a6e8f3b8297d179937 (diff)
parent6fcde90466738b84a073e4f4d18c50015ee29fb2 (diff)
downloadlinux-stericsson-2d6bb6adb714b133db92ccd4bfc9c20f75f71f3f.tar.gz
Merge tag 'stackleak-v4.20-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux
Pull stackleak gcc plugin from Kees Cook: "Please pull this new GCC plugin, stackleak, for v4.20-rc1. This plugin was ported from grsecurity by Alexander Popov. It provides efficient stack content poisoning at syscall exit. This creates a defense against at least two classes of flaws: - Uninitialized stack usage. (We continue to work on improving the compiler to do this in other ways: e.g. unconditional zero init was proposed to GCC and Clang, and more plugin work has started too). - Stack content exposure. By greatly reducing the lifetime of valid stack contents, exposures via either direct read bugs or unknown cache side-channels become much more difficult to exploit. This complements the existing buddy and heap poisoning options, but provides the coverage for stacks. The x86 hooks are included in this series (which have been reviewed by Ingo, Dave Hansen, and Thomas Gleixner). The arm64 hooks have already been merged through the arm64 tree (written by Laura Abbott and reviewed by Mark Rutland and Will Deacon). With VLAs having been removed this release, there is no need for alloca() protection, so it has been removed from the plugin" * tag 'stackleak-v4.20-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: arm64: Drop unneeded stackleak_check_alloca() stackleak: Allow runtime disabling of kernel stack erasing doc: self-protection: Add information about STACKLEAK feature fs/proc: Show STACKLEAK metrics in the /proc file system lkdtm: Add a test for STACKLEAK gcc-plugins: Add STACKLEAK plugin for tracking the kernel stack x86/entry: Add STACKLEAK erasing the kernel stack at the end of syscalls
Diffstat (limited to 'arch/x86/entry/entry_64.S')
-rw-r--r--arch/x86/entry/entry_64.S3
1 files changed, 3 insertions, 0 deletions
diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S
index 4d7a2d9d44cf..ce25d84023c0 100644
--- a/arch/x86/entry/entry_64.S
+++ b/arch/x86/entry/entry_64.S
@@ -266,6 +266,8 @@ syscall_return_via_sysret:
* We are on the trampoline stack. All regs except RDI are live.
* We can do future final exit work right here.
*/
+ STACKLEAK_ERASE_NOCLOBBER
+
SWITCH_TO_USER_CR3_STACK scratch_reg=%rdi
popq %rdi
@@ -625,6 +627,7 @@ GLOBAL(swapgs_restore_regs_and_return_to_usermode)
* We are on the trampoline stack. All regs except RDI are live.
* We can do future final exit work right here.
*/
+ STACKLEAK_ERASE_NOCLOBBER
SWITCH_TO_USER_CR3_STACK scratch_reg=%rdi