ARM: 9485/1: mm: acquire mmap write lock around show_pte() for user faultsgrafted

When CONFIG_DEBUG_USER=y, and cmdline "user_debug=31" is set,
a user fault may trigger show_pte() without any lock.
If another thread in the same process concurrently calls munmap(),
the page table pages may be freed while show_pte() is still traversing
them, causing a use-after-free in show_pte().

If CONFIG_ARM_LPAE=y, this may cause a kernel panic if the pages table
of PMD are freed when show_pte() is running.

Acquire mmap_write_lock() around show_pte() for user faults to fix the
contention.

For user faults, additionally restrict that show_pte() is called only
when the addr is a user-space address (addr < TASK_SIZE). This is because
the lock of tsk->mm only protects the virtual memory of user address space,
furthermore, dumping the page tables of a kernel-space address for user
faults is unnecessary and may have security implications.

Keep everything unchanged for kernel faults, because the kernel is
already in the "oops" state, acquiring a lock may risk a deadlock.

Co-developed-by: Qi Xi <xiqi2@huawei.com>

Fixes: 6d021b724481 ("ARM: dump pgd, pmd and pte states on unhandled data abort faults")
Link: https://lore.kernel.org/20260716014022.2823-1-xieyuanbin1@huawei.com
Acked-by: Lorenzo Stoakes (ARM) <ljs@kernel.org>
Reviewed-by: Linus Walleij <linusw@kernel.org>
Signed-off-by: Qi Xi <xiqi2@huawei.com>
Signed-off-by: Xie Yuanbin <xieyuanbin1@huawei.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>

1 files changed, 207 insertions, 0 deletions

diff --git a/crypto/Makefile b/crypto/Makefile
new file mode 100644
index 000000000..8386d55a9
--- /dev/null
+++ b/crypto/Makefile
@@ -0,0 +1,207 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Cryptographic API
+#
+
+CONTEXT_ANALYSIS := y
+
+obj-$(CONFIG_CRYPTO) += crypto.o
+crypto-y := api.o cipher.o
+
+obj-$(CONFIG_CRYPTO_ENGINE) += crypto_engine.o
+obj-$(CONFIG_CRYPTO_FIPS) += fips.o
+
+crypto_algapi-$(CONFIG_PROC_FS) += proc.o
+crypto_algapi-y := algapi.o scatterwalk.o $(crypto_algapi-y)
+obj-$(CONFIG_CRYPTO_ALGAPI2) += crypto_algapi.o
+
+obj-$(CONFIG_CRYPTO_AEAD2) += aead.o
+obj-$(CONFIG_CRYPTO_GENIV) += geniv.o
+
+crypto_skcipher-y += lskcipher.o
+crypto_skcipher-y += skcipher.o
+
+obj-$(CONFIG_CRYPTO_SKCIPHER2) += crypto_skcipher.o
+ifeq ($(CONFIG_BPF_SYSCALL),y)
+obj-$(CONFIG_CRYPTO_SKCIPHER2) += bpf_crypto_skcipher.o
+endif
+
+obj-$(CONFIG_CRYPTO_SEQIV) += seqiv.o
+obj-$(CONFIG_CRYPTO_ECHAINIV) += echainiv.o
+
+crypto_hash-y += ahash.o
+crypto_hash-y += shash.o
+obj-$(CONFIG_CRYPTO_HASH2) += crypto_hash.o
+
+obj-$(CONFIG_CRYPTO_AKCIPHER2) += akcipher.o
+obj-$(CONFIG_CRYPTO_SIG2) += sig.o
+obj-$(CONFIG_CRYPTO_KPP2) += kpp.o
+
+dh_generic-y := dh.o
+dh_generic-y += dh_helper.o
+obj-$(CONFIG_CRYPTO_DH) += dh_generic.o
+
+$(obj)/rsapubkey.asn1.o: $(obj)/rsapubkey.asn1.c $(obj)/rsapubkey.asn1.h
+$(obj)/rsaprivkey.asn1.o: $(obj)/rsaprivkey.asn1.c $(obj)/rsaprivkey.asn1.h
+$(obj)/rsa_helper.o: $(obj)/rsapubkey.asn1.h $(obj)/rsaprivkey.asn1.h
+
+rsa_generic-y := rsapubkey.asn1.o
+rsa_generic-y += rsaprivkey.asn1.o
+rsa_generic-y += rsa.o
+rsa_generic-y += rsa_helper.o
+rsa_generic-y += rsa-pkcs1pad.o
+rsa_generic-y += rsassa-pkcs1.o
+obj-$(CONFIG_CRYPTO_RSA) += rsa_generic.o
+
+$(obj)/ecdsasignature.asn1.o: $(obj)/ecdsasignature.asn1.c $(obj)/ecdsasignature.asn1.h
+$(obj)/ecdsa-x962.o: $(obj)/ecdsasignature.asn1.h
+ecdsa_generic-y += ecdsa.o
+ecdsa_generic-y += ecdsa-x962.o
+ecdsa_generic-y += ecdsa-p1363.o
+ecdsa_generic-y += ecdsasignature.asn1.o
+obj-$(CONFIG_CRYPTO_ECDSA) += ecdsa_generic.o
+
+obj-$(CONFIG_CRYPTO_MLDSA) += mldsa.o
+
+crypto_acompress-y := acompress.o
+crypto_acompress-y += scompress.o
+obj-$(CONFIG_CRYPTO_ACOMP2) += crypto_acompress.o
+
+cryptomgr-y := algboss.o testmgr.o
+
+obj-$(CONFIG_CRYPTO_MANAGER2) += cryptomgr.o
+obj-$(CONFIG_CRYPTO_USER) += crypto_user.o
+obj-$(CONFIG_CRYPTO_CMAC) += cmac.o
+obj-$(CONFIG_CRYPTO_HMAC) += hmac.o
+obj-$(CONFIG_CRYPTO_XCBC) += xcbc.o
+obj-$(CONFIG_CRYPTO_NULL) += crypto_null.o
+obj-$(CONFIG_CRYPTO_MD4) += md4.o
+obj-$(CONFIG_CRYPTO_MD5) += md5.o
+obj-$(CONFIG_CRYPTO_RMD160) += rmd160.o
+obj-$(CONFIG_CRYPTO_SHA1) += sha1.o
+obj-$(CONFIG_CRYPTO_SHA256) += sha256.o
+obj-$(CONFIG_CRYPTO_SHA512) += sha512.o
+obj-$(CONFIG_CRYPTO_SHA3) += sha3.o
+obj-$(CONFIG_CRYPTO_SM3) += sm3.o
+obj-$(CONFIG_CRYPTO_STREEBOG) += streebog_generic.o
+obj-$(CONFIG_CRYPTO_WP512) += wp512.o
+CFLAGS_wp512.o := $(call cc-option,-fno-schedule-insns)  # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79149
+obj-$(CONFIG_CRYPTO_BLAKE2B) += blake2b.o
+obj-$(CONFIG_CRYPTO_ECB) += ecb.o
+obj-$(CONFIG_CRYPTO_CBC) += cbc.o
+obj-$(CONFIG_CRYPTO_CTS) += cts.o
+obj-$(CONFIG_CRYPTO_LRW) += lrw.o
+obj-$(CONFIG_CRYPTO_XTS) += xts.o
+obj-$(CONFIG_CRYPTO_CTR) += ctr.o
+obj-$(CONFIG_CRYPTO_XCTR) += xctr.o
+obj-$(CONFIG_CRYPTO_HCTR2) += hctr2.o
+obj-$(CONFIG_CRYPTO_ADIANTUM) += adiantum.o
+obj-$(CONFIG_CRYPTO_GCM) += gcm.o
+obj-$(CONFIG_CRYPTO_CCM) += ccm.o
+obj-$(CONFIG_CRYPTO_CHACHA20POLY1305) += chacha20poly1305.o
+obj-$(CONFIG_CRYPTO_AEGIS128) += aegis128.o
+aegis128-y := aegis128-core.o
+
+CFLAGS_aegis128-neon-inner.o += $(CC_FLAGS_FPU)
+CFLAGS_REMOVE_aegis128-neon-inner.o += $(CC_FLAGS_NO_FPU)
+ifeq ($(ARCH),arm)
+CFLAGS_aegis128-neon-inner.o += -march=armv8-a -mfpu=crypto-neon-fp-armv8
+aegis128-$(CONFIG_CRYPTO_AEGIS128_SIMD) += aegis128-neon.o aegis128-neon-inner.o
+endif
+ifeq ($(ARCH),arm64)
+aegis128-cflags-y := -mcpu=generic+crypto
+aegis128-cflags-$(CONFIG_CC_IS_GCC) += -ffixed-q16 -ffixed-q17 -ffixed-q18 \
+				       -ffixed-q19 -ffixed-q20 -ffixed-q21 \
+				       -ffixed-q22 -ffixed-q23 -ffixed-q24 \
+				       -ffixed-q25 -ffixed-q26 -ffixed-q27 \
+				       -ffixed-q28 -ffixed-q29 -ffixed-q30 \
+				       -ffixed-q31
+CFLAGS_aegis128-neon-inner.o += $(aegis128-cflags-y)
+aegis128-$(CONFIG_CRYPTO_AEGIS128_SIMD) += aegis128-neon.o aegis128-neon-inner.o
+endif
+
+obj-$(CONFIG_CRYPTO_PCRYPT) += pcrypt.o
+obj-$(CONFIG_CRYPTO_CRYPTD) += cryptd.o
+obj-$(CONFIG_CRYPTO_DES) += des_generic.o
+obj-$(CONFIG_CRYPTO_BLOWFISH) += blowfish_generic.o
+obj-$(CONFIG_CRYPTO_BLOWFISH_COMMON) += blowfish_common.o
+obj-$(CONFIG_CRYPTO_TWOFISH) += twofish_generic.o
+obj-$(CONFIG_CRYPTO_TWOFISH_COMMON) += twofish_common.o
+obj-$(CONFIG_CRYPTO_SERPENT) += serpent_generic.o
+CFLAGS_serpent_generic.o := $(call cc-option,-fsched-pressure)  # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79149
+obj-$(CONFIG_CRYPTO_AES) += aes.o
+obj-$(CONFIG_CRYPTO_SM4) += sm4.o
+obj-$(CONFIG_CRYPTO_SM4_GENERIC) += sm4_generic.o
+obj-$(CONFIG_CRYPTO_CAMELLIA) += camellia_generic.o
+obj-$(CONFIG_CRYPTO_CAST_COMMON) += cast_common.o
+obj-$(CONFIG_CRYPTO_CAST5) += cast5_generic.o
+obj-$(CONFIG_CRYPTO_CAST6) += cast6_generic.o
+obj-$(CONFIG_CRYPTO_ARC4) += arc4.o
+obj-$(CONFIG_CRYPTO_TEA) += tea.o
+obj-$(CONFIG_CRYPTO_KHAZAD) += khazad.o
+obj-$(CONFIG_CRYPTO_ANUBIS) += anubis.o
+obj-$(CONFIG_CRYPTO_SEED) += seed.o
+obj-$(CONFIG_CRYPTO_ARIA) += aria_generic.o
+obj-$(CONFIG_CRYPTO_CHACHA20) += chacha.o
+CFLAGS_chacha.o += -DARCH=$(ARCH)
+obj-$(CONFIG_CRYPTO_DEFLATE) += deflate.o
+obj-$(CONFIG_CRYPTO_CRC32C) += crc32c-cryptoapi.o
+crc32c-cryptoapi-y := crc32c.o
+obj-$(CONFIG_CRYPTO_CRC32) += crc32-cryptoapi.o
+crc32-cryptoapi-y := crc32.o
+obj-$(CONFIG_CRYPTO_AUTHENC) += authenc.o authencesn.o
+obj-$(CONFIG_CRYPTO_KRB5ENC) += krb5enc.o
+obj-$(CONFIG_CRYPTO_LZO) += lzo.o lzo-rle.o
+obj-$(CONFIG_CRYPTO_LZ4) += lz4.o
+obj-$(CONFIG_CRYPTO_LZ4HC) += lz4hc.o
+obj-$(CONFIG_CRYPTO_XXHASH) += xxhash_generic.o
+obj-$(CONFIG_CRYPTO_842) += 842.o
+obj-$(CONFIG_CRYPTO_RNG2) += rng.o
+obj-$(CONFIG_CRYPTO_DRBG) += drbg.o
+obj-$(CONFIG_CRYPTO_JITTERENTROPY) += jitterentropy_rng.o
+CFLAGS_jitterentropy.o = -O0
+KASAN_SANITIZE_jitterentropy.o = n
+UBSAN_SANITIZE_jitterentropy.o = n
+jitterentropy_rng-y := jitterentropy.o jitterentropy-kcapi.o
+obj-$(CONFIG_CRYPTO_JITTERENTROPY_TESTINTERFACE) += jitterentropy-testing.o
+obj-$(CONFIG_CRYPTO_BENCHMARK) += tcrypt.o
+obj-$(CONFIG_CRYPTO_USER_API) += af_alg.o
+obj-$(CONFIG_CRYPTO_USER_API_HASH) += algif_hash.o
+obj-$(CONFIG_CRYPTO_USER_API_SKCIPHER) += algif_skcipher.o
+obj-$(CONFIG_CRYPTO_USER_API_RNG) += algif_rng.o
+obj-$(CONFIG_CRYPTO_USER_API_AEAD) += algif_aead.o
+obj-$(CONFIG_CRYPTO_ZSTD) += zstd.o
+obj-$(CONFIG_CRYPTO_ECC) += ecc.o
+obj-$(CONFIG_CRYPTO_ESSIV) += essiv.o
+
+# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=124949
+ifeq ($(CONFIG_ARM)$(CONFIG_KASAN_STACK)$(CONFIG_CC_IS_GCC),yyy)
+CFLAGS_ecc.o += $(call cc-option,-Wframe-larger-than=1536)
+endif
+
+ecdh_generic-y += ecdh.o
+ecdh_generic-y += ecdh_helper.o
+obj-$(CONFIG_CRYPTO_ECDH) += ecdh_generic.o
+
+$(obj)/ecrdsa_params.asn1.o: $(obj)/ecrdsa_params.asn1.c $(obj)/ecrdsa_params.asn1.h
+$(obj)/ecrdsa_pub_key.asn1.o: $(obj)/ecrdsa_pub_key.asn1.c $(obj)/ecrdsa_pub_key.asn1.h
+$(obj)/ecrdsa.o: $(obj)/ecrdsa_params.asn1.h $(obj)/ecrdsa_pub_key.asn1.h
+ecrdsa_generic-y += ecrdsa.o
+ecrdsa_generic-y += ecrdsa_params.asn1.o
+ecrdsa_generic-y += ecrdsa_pub_key.asn1.o
+obj-$(CONFIG_CRYPTO_ECRDSA) += ecrdsa_generic.o
+
+#
+# generic algorithms and the async_tx api
+#
+obj-$(CONFIG_ASYNC_CORE) += async_tx/
+obj-$(CONFIG_ASYMMETRIC_KEY_TYPE) += asymmetric_keys/
+crypto_simd-y := simd.o
+obj-$(CONFIG_CRYPTO_SIMD) += crypto_simd.o
+
+#
+# Key derivation function
+#
+obj-$(CONFIG_CRYPTO_KDF800108_CTR) += kdf_sp800108.o
+
+obj-$(CONFIG_CRYPTO_KRB5) += krb5/