Skip to main content

Browse the archive

Revision a4aeaa06d45e90f9b279f0b09de84bd00006e733 authored by Yang Shi on 28 October 2021, 21:36:30 UTC, committed by Linus Torvalds on 29 October 2021, 00:18:55 UTC 
mm: khugepaged: skip huge page collapse for special files
 
The read-only THP for filesystems will collapse THP for files opened
readonly and mapped with VM_EXEC.  The intended usecase is to avoid TLB
misses for large text segments.  But it doesn't restrict the file types
so a THP could be collapsed for a non-regular file, for example, block
device, if it is opened readonly and mapped with EXEC permission.  This
may cause bugs, like [1] and [2].

This is definitely not the intended usecase, so just collapse THP for
regular files in order to close the attack surface.

[shy828301@gmail.com: fix vm_file check [3]]

Link: https://lore.kernel.org/lkml/CACkBjsYwLYLRmX8GpsDpMthagWOjWWrNxqY6ZLNQVr6yx+f5vA@mail.gmail.com/ [1]
Link: https://lore.kernel.org/linux-mm/000000000000c6a82505ce284e4c@google.com/ [2]
Link: https://lkml.kernel.org/r/CAHbLzkqTW9U3VvTu1Ki5v_cLRC9gHW+znBukg_ycergE0JWj-A@mail.gmail.com [3]
Link: https://lkml.kernel.org/r/20211027195221.3825-1-shy828301@gmail.com
Fixes: 99cb0dbd47a1 ("mm,thp: add read-only THP support for (non-shmem) FS")
Signed-off-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Yang Shi <shy828301@gmail.com>
Reported-by: Hao Sun <sunhao.th@gmail.com>
Reported-by: syzbot+aae069be1de40fb11825@syzkaller.appspotmail.com
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Song Liu <songliubraving@fb.com>
Cc: Andrea Righi <andrea.righi@canonical.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1 parent 74c42e1
Raw File
aegis128-neon.c 
// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Copyright (C) 2019 Linaro Ltd <ard.biesheuvel@linaro.org>
 */

#include <asm/cpufeature.h>
#include <asm/neon.h>

#include "aegis.h"

void crypto_aegis128_init_neon(void *state, const void *key, const void *iv);
void crypto_aegis128_update_neon(void *state, const void *msg);
void crypto_aegis128_encrypt_chunk_neon(void *state, void *dst, const void *src,
					unsigned int size);
void crypto_aegis128_decrypt_chunk_neon(void *state, void *dst, const void *src,
					unsigned int size);
int crypto_aegis128_final_neon(void *state, void *tag_xor,
			       unsigned int assoclen,
			       unsigned int cryptlen,
			       unsigned int authsize);

int aegis128_have_aes_insn __ro_after_init;

bool crypto_aegis128_have_simd(void)
{
	if (cpu_have_feature(cpu_feature(AES))) {
		aegis128_have_aes_insn = 1;
		return true;
	}
	return IS_ENABLED(CONFIG_ARM64);
}

void crypto_aegis128_init_simd(struct aegis_state *state,
			       const union aegis_block *key,
			       const u8 *iv)
{
	kernel_neon_begin();
	crypto_aegis128_init_neon(state, key, iv);
	kernel_neon_end();
}

void crypto_aegis128_update_simd(struct aegis_state *state, const void *msg)
{
	kernel_neon_begin();
	crypto_aegis128_update_neon(state, msg);
	kernel_neon_end();
}

void crypto_aegis128_encrypt_chunk_simd(struct aegis_state *state, u8 *dst,
					const u8 *src, unsigned int size)
{
	kernel_neon_begin();
	crypto_aegis128_encrypt_chunk_neon(state, dst, src, size);
	kernel_neon_end();
}

void crypto_aegis128_decrypt_chunk_simd(struct aegis_state *state, u8 *dst,
					const u8 *src, unsigned int size)
{
	kernel_neon_begin();
	crypto_aegis128_decrypt_chunk_neon(state, dst, src, size);
	kernel_neon_end();
}

int crypto_aegis128_final_simd(struct aegis_state *state,
			       union aegis_block *tag_xor,
			       unsigned int assoclen,
			       unsigned int cryptlen,
			       unsigned int authsize)
{
	int ret;

	kernel_neon_begin();
	ret = crypto_aegis128_final_neon(state, tag_xor, assoclen, cryptlen,
					 authsize);
	kernel_neon_end();

	return ret;
}
back to top