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From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	stable@vger.kernel.org, Guenter Roeck <linux@roeck-us.net>,
	Thadeu Lima de Souza Cascardo <cascardo@canonical.com>,
	"Peter Zijlstra (Intel)" <peterz@infradead.org>,
	Borislav Petkov <bp@suse.de>,
	Josh Poimboeuf <jpoimboe@kernel.org>,
	Linus Torvalds <torvalds@linux-foundation.org>
Subject: [PATCH 5.18 64/70] efi/x86: use naked RET on mixed mode call wrapper
Date: Fri, 22 Jul 2022 11:07:59 +0200	[thread overview]
Message-ID: <20220722090654.476559224@linuxfoundation.org> (raw)
In-Reply-To: <20220722090650.665513668@linuxfoundation.org>

From: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>

commit 51a6fa0732d6be6a44e0032752ad2ac10d67c796 upstream.

When running with return thunks enabled under 32-bit EFI, the system
crashes with:

  kernel tried to execute NX-protected page - exploit attempt? (uid: 0)
  BUG: unable to handle page fault for address: 000000005bc02900
  #PF: supervisor instruction fetch in kernel mode
  #PF: error_code(0x0011) - permissions violation
  PGD 18f7063 P4D 18f7063 PUD 18ff063 PMD 190e063 PTE 800000005bc02063
  Oops: 0011 [#1] PREEMPT SMP PTI
  CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.19.0-rc6+ #166
  Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015
  RIP: 0010:0x5bc02900
  Code: Unable to access opcode bytes at RIP 0x5bc028d6.
  RSP: 0018:ffffffffb3203e10 EFLAGS: 00010046
  RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000048
  RDX: 000000000190dfac RSI: 0000000000001710 RDI: 000000007eae823b
  RBP: ffffffffb3203e70 R08: 0000000001970000 R09: ffffffffb3203e28
  R10: 747563657865206c R11: 6c6977203a696665 R12: 0000000000001710
  R13: 0000000000000030 R14: 0000000001970000 R15: 0000000000000001
  FS:  0000000000000000(0000) GS:ffff8e013ca00000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0018 ES: 0018 CR0: 0000000080050033
  CR2: 000000005bc02900 CR3: 0000000001930000 CR4: 00000000000006f0
  Call Trace:
   ? efi_set_virtual_address_map+0x9c/0x175
   efi_enter_virtual_mode+0x4a6/0x53e
   start_kernel+0x67c/0x71e
   x86_64_start_reservations+0x24/0x2a
   x86_64_start_kernel+0xe9/0xf4
   secondary_startup_64_no_verify+0xe5/0xeb

That's because it cannot jump to the return thunk from the 32-bit code.

Using a naked RET and marking it as safe allows the system to proceed
booting.

Fixes: aa3d480315ba ("x86: Use return-thunk in asm code")
Reported-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Borislav Petkov <bp@suse.de>
Cc: Josh Poimboeuf <jpoimboe@kernel.org>
Cc: <stable@vger.kernel.org>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 arch/x86/platform/efi/efi_thunk_64.S |    5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

--- a/arch/x86/platform/efi/efi_thunk_64.S
+++ b/arch/x86/platform/efi/efi_thunk_64.S
@@ -23,6 +23,7 @@
 #include <linux/objtool.h>
 #include <asm/page_types.h>
 #include <asm/segment.h>
+#include <asm/nospec-branch.h>
 
 	.text
 	.code64
@@ -75,7 +76,9 @@ STACK_FRAME_NON_STANDARD __efi64_thunk
 1:	movq	0x20(%rsp), %rsp
 	pop	%rbx
 	pop	%rbp
-	RET
+	ANNOTATE_UNRET_SAFE
+	ret
+	int3
 
 	.code32
 2:	pushl	$__KERNEL_CS



  parent reply	other threads:[~2022-07-22  9:16 UTC|newest]

Thread overview: 81+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-07-22  9:06 [PATCH 5.18 00/70] 5.18.14-rc1 review Greg Kroah-Hartman
2022-07-22  9:06 ` [PATCH 5.18 01/70] x86/traps: Use pt_regs directly in fixup_bad_iret() Greg Kroah-Hartman
2022-07-22  9:06 ` [PATCH 5.18 02/70] x86/entry: Switch the stack after error_entry() returns Greg Kroah-Hartman
2022-07-22  9:06 ` [PATCH 5.18 03/70] x86/entry: Move PUSH_AND_CLEAR_REGS out of error_entry() Greg Kroah-Hartman
2022-07-22  9:06 ` [PATCH 5.18 04/70] x86/entry: Dont call error_entry() for XENPV Greg Kroah-Hartman
2022-07-22  9:07 ` [PATCH 5.18 05/70] x86/entry: Remove skip_r11rcx Greg Kroah-Hartman
2022-07-22  9:07 ` [PATCH 5.18 06/70] x86/kvm/vmx: Make noinstr clean Greg Kroah-Hartman
2022-07-22  9:07 ` [PATCH 5.18 07/70] x86/cpufeatures: Move RETPOLINE flags to word 11 Greg Kroah-Hartman
2022-07-22  9:07 ` [PATCH 5.18 08/70] x86/retpoline: Cleanup some #ifdefery Greg Kroah-Hartman
2022-07-22  9:07 ` [PATCH 5.18 09/70] x86/retpoline: Swizzle retpoline thunk Greg Kroah-Hartman
2022-07-22  9:07 ` [PATCH 5.18 10/70] x86/retpoline: Use -mfunction-return Greg Kroah-Hartman
2022-07-22  9:07 ` [PATCH 5.18 11/70] x86: Undo return-thunk damage Greg Kroah-Hartman
2022-07-22  9:07 ` [PATCH 5.18 12/70] x86,objtool: Create .return_sites Greg Kroah-Hartman
2022-07-22  9:07 ` [PATCH 5.18 13/70] objtool: skip non-text sections when adding return-thunk sites Greg Kroah-Hartman
2022-07-25  5:44   ` Jiri Slaby
2022-07-25  8:37     ` Greg Kroah-Hartman
2022-07-25 11:49     ` Thadeu Lima de Souza Cascardo
2022-07-22  9:07 ` [PATCH 5.18 14/70] x86,static_call: Use alternative RET encoding Greg Kroah-Hartman
2022-07-22  9:07 ` [PATCH 5.18 15/70] x86/ftrace: " Greg Kroah-Hartman
2022-07-22  9:07 ` [PATCH 5.18 16/70] x86/bpf: " Greg Kroah-Hartman
2022-07-22  9:07 ` [PATCH 5.18 17/70] x86/kvm: Fix SETcc emulation for return thunks Greg Kroah-Hartman
2022-07-22  9:07 ` [PATCH 5.18 18/70] x86/vsyscall_emu/64: Dont use RET in vsyscall emulation Greg Kroah-Hartman
2022-07-22  9:07 ` [PATCH 5.18 19/70] x86/sev: Avoid using __x86_return_thunk Greg Kroah-Hartman
2022-07-22  9:07 ` [PATCH 5.18 20/70] x86: Use return-thunk in asm code Greg Kroah-Hartman
2022-07-22  9:07 ` [PATCH 5.18 21/70] x86/entry: Avoid very early RET Greg Kroah-Hartman
2022-07-22  9:07 ` [PATCH 5.18 22/70] objtool: Treat .text.__x86.* as noinstr Greg Kroah-Hartman
2022-07-22  9:07 ` [PATCH 5.18 23/70] x86: Add magic AMD return-thunk Greg Kroah-Hartman
2022-07-22  9:07 ` [PATCH 5.18 24/70] x86/bugs: Report AMD retbleed vulnerability Greg Kroah-Hartman
2022-07-22  9:07 ` [PATCH 5.18 25/70] x86/bugs: Add AMD retbleed= boot parameter Greg Kroah-Hartman
2022-07-22  9:07 ` [PATCH 5.18 26/70] x86/bugs: Enable STIBP for JMP2RET Greg Kroah-Hartman
2022-07-22  9:07 ` [PATCH 5.18 27/70] x86/bugs: Keep a per-CPU IA32_SPEC_CTRL value Greg Kroah-Hartman
2022-07-22  9:07 ` [PATCH 5.18 28/70] x86/entry: Add kernel IBRS implementation Greg Kroah-Hartman
2022-07-22  9:07 ` [PATCH 5.18 29/70] x86/bugs: Optimize SPEC_CTRL MSR writes Greg Kroah-Hartman
2022-07-22  9:07 ` [PATCH 5.18 30/70] x86/speculation: Add spectre_v2=ibrs option to support Kernel IBRS Greg Kroah-Hartman
2022-07-22  9:07 ` [PATCH 5.18 31/70] x86/bugs: Split spectre_v2_select_mitigation() and spectre_v2_user_select_mitigation() Greg Kroah-Hartman
2022-07-22  9:07 ` [PATCH 5.18 32/70] x86/bugs: Report Intel retbleed vulnerability Greg Kroah-Hartman
2022-07-22  9:07 ` [PATCH 5.18 33/70] intel_idle: Disable IBRS during long idle Greg Kroah-Hartman
2022-07-22  9:07 ` [PATCH 5.18 34/70] objtool: Update Retpoline validation Greg Kroah-Hartman
2022-07-22  9:07 ` [PATCH 5.18 35/70] x86/xen: Rename SYS* entry points Greg Kroah-Hartman
2022-07-22  9:07 ` [PATCH 5.18 36/70] x86/xen: Add UNTRAIN_RET Greg Kroah-Hartman
2022-07-22  9:07 ` [PATCH 5.18 37/70] x86/bugs: Add retbleed=ibpb Greg Kroah-Hartman
2022-07-22  9:07 ` [PATCH 5.18 38/70] x86/bugs: Do IBPB fallback check only once Greg Kroah-Hartman
2022-07-22  9:07 ` [PATCH 5.18 39/70] objtool: Add entry UNRET validation Greg Kroah-Hartman
2022-07-22  9:07 ` [PATCH 5.18 40/70] x86/cpu/amd: Add Spectral Chicken Greg Kroah-Hartman
2022-07-22  9:07 ` [PATCH 5.18 41/70] x86/speculation: Fix RSB filling with CONFIG_RETPOLINE=n Greg Kroah-Hartman
2022-07-22  9:07 ` [PATCH 5.18 42/70] x86/speculation: Fix firmware entry SPEC_CTRL handling Greg Kroah-Hartman
2022-07-22  9:07 ` [PATCH 5.18 43/70] x86/speculation: Fix SPEC_CTRL write on SMT state change Greg Kroah-Hartman
2022-07-22  9:07 ` [PATCH 5.18 44/70] x86/speculation: Use cached host SPEC_CTRL value for guest entry/exit Greg Kroah-Hartman
2022-07-22  9:07 ` [PATCH 5.18 45/70] x86/speculation: Remove x86_spec_ctrl_mask Greg Kroah-Hartman
2022-07-22  9:07 ` [PATCH 5.18 46/70] objtool: Re-add UNWIND_HINT_{SAVE_RESTORE} Greg Kroah-Hartman
2022-07-22  9:07 ` [PATCH 5.18 47/70] KVM: VMX: Flatten __vmx_vcpu_run() Greg Kroah-Hartman
2022-07-22  9:07 ` [PATCH 5.18 48/70] KVM: VMX: Convert launched argument to flags Greg Kroah-Hartman
2022-07-22  9:07 ` [PATCH 5.18 49/70] KVM: VMX: Prevent guest RSB poisoning attacks with eIBRS Greg Kroah-Hartman
2022-07-22  9:07 ` [PATCH 5.18 50/70] KVM: VMX: Fix IBRS handling after vmexit Greg Kroah-Hartman
2022-07-22  9:07 ` [PATCH 5.18 51/70] x86/speculation: Fill RSB on vmexit for IBRS Greg Kroah-Hartman
2022-07-22  9:07 ` [PATCH 5.18 52/70] KVM: VMX: Prevent RSB underflow before vmenter Greg Kroah-Hartman
2022-07-22  9:07 ` [PATCH 5.18 53/70] x86/common: Stamp out the stepping madness Greg Kroah-Hartman
2022-07-22  9:07 ` [PATCH 5.18 54/70] x86/cpu/amd: Enumerate BTC_NO Greg Kroah-Hartman
2022-07-22  9:07 ` [PATCH 5.18 55/70] x86/retbleed: Add fine grained Kconfig knobs Greg Kroah-Hartman
2022-07-22  9:07 ` [PATCH 5.18 56/70] x86/bugs: Add Cannon lake to RETBleed affected CPU list Greg Kroah-Hartman
2022-07-22  9:07 ` [PATCH 5.18 57/70] x86/entry: Move PUSH_AND_CLEAR_REGS() back into error_entry Greg Kroah-Hartman
2022-07-22  9:07 ` [PATCH 5.18 58/70] x86/bugs: Do not enable IBPB-on-entry when IBPB is not supported Greg Kroah-Hartman
2022-07-22  9:07 ` [PATCH 5.18 59/70] x86/kexec: Disable RET on kexec Greg Kroah-Hartman
2022-07-22  9:07 ` [PATCH 5.18 60/70] x86/speculation: Disable RRSBA behavior Greg Kroah-Hartman
2022-07-22  9:07 ` [PATCH 5.18 61/70] x86/static_call: Serialize __static_call_fixup() properly Greg Kroah-Hartman
2022-07-22  9:07 ` [PATCH 5.18 62/70] x86/asm/32: Fix ANNOTATE_UNRET_SAFE use on 32-bit Greg Kroah-Hartman
2022-07-22  9:07 ` [PATCH 5.18 63/70] x86/speculation: Use DECLARE_PER_CPU for x86_spec_ctrl_current Greg Kroah-Hartman
2022-07-22  9:07 ` Greg Kroah-Hartman [this message]
2022-07-22  9:08 ` [PATCH 5.18 65/70] x86/kvm: fix FASTOP_SIZE when return thunks are enabled Greg Kroah-Hartman
2022-07-22  9:08 ` [PATCH 5.18 66/70] KVM: emulate: do not adjust size of fastop and setcc subroutines Greg Kroah-Hartman
2022-07-22  9:08 ` [PATCH 5.18 67/70] tools arch x86: Sync the msr-index.h copy with the kernel sources Greg Kroah-Hartman
2022-07-22  9:08 ` [PATCH 5.18 68/70] tools headers cpufeatures: Sync " Greg Kroah-Hartman
2022-07-22  9:08 ` [PATCH 5.18 69/70] x86/bugs: Remove apostrophe typo Greg Kroah-Hartman
2022-07-22  9:08 ` [PATCH 5.18 70/70] um: Add missing apply_returns() Greg Kroah-Hartman
2022-07-22 18:37 ` [PATCH 5.18 00/70] 5.18.14-rc1 review Florian Fainelli
2022-07-22 18:55 ` Ron Economos
2022-07-22 19:33 ` Naresh Kamboju
2022-07-22 21:59 ` Guenter Roeck
2022-07-23  2:02 ` Bagas Sanjaya
2022-07-23  8:39 ` Rudi Heitbaum
2022-07-23  8:53 ` Sudip Mukherjee (Codethink)

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