From 78004e9a87f240df03e2f73120d291763c32e0a7 Mon Sep 17 00:00:00 2001 From: Ali Ahmet Memis Date: Fri, 21 Aug 2026 01:45:27 +0000 Subject: openrisc: fix arbitrary kernel memory access via or1k_atomic syscall sys_or1k_atomic() (syscall 244 in the "or1k" ABI) takes two user pointers, v1 and v2, and swaps the words they point to in hand-written assembly. l.lwz r29,0(r4) l.lwz r27,0(r5) l.sw 0(r4),r27 l.sw 0(r5),r29 The pointers are not checked with access_ok(). The four memory accesses also have no exception table entries. A caller passes a kernel address as either pointer, and the syscall reads from and writes to it directly. This gives an unprivileged process a kernel read/write primitive. It overwrites kernel data such as the sys_call_table, gaining code execution in kernel context. Check both pointers before entering the critical section. Add fixups for the four memory accesses so faults on valid but unmapped user addresses return -EFAULT. [shorne@gmail.com: fix comment style] Fixes: 9d02a4283e9c ("OpenRISC: Boot code") Cc: stable@vger.kernel.org Signed-off-by: Ali Ahmet Memis Signed-off-by: Stafford Horne --- security/integrity/evm/Kconfig | 76 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 76 insertions(+) create mode 100644 security/integrity/evm/Kconfig (limited to 'security/integrity/evm/Kconfig') diff --git a/security/integrity/evm/Kconfig b/security/integrity/evm/Kconfig new file mode 100644 index 000000000..861b3baca --- /dev/null +++ b/security/integrity/evm/Kconfig @@ -0,0 +1,76 @@ +# SPDX-License-Identifier: GPL-2.0-only +config EVM + bool "EVM support" + select KEYS + select ENCRYPTED_KEYS + select CRYPTO_HMAC + select CRYPTO_SHA1 + select CRYPTO_HASH_INFO + select SECURITY_PATH + default n + help + EVM protects a file's security extended attributes against + integrity attacks. + + If you are unsure how to answer this question, answer N. + +config EVM_ATTR_FSUUID + bool "FSUUID (version 2)" + default y + depends on EVM + help + Include filesystem UUID for HMAC calculation. + + Default value is 'selected', which is former version 2. + if 'not selected', it is former version 1 + + WARNING: changing the HMAC calculation method or adding + additional info to the calculation, requires existing EVM + labeled file systems to be relabeled. + +config EVM_EXTRA_SMACK_XATTRS + bool "Additional SMACK xattrs" + depends on EVM && SECURITY_SMACK + default n + help + Include additional SMACK xattrs for HMAC calculation. + + In addition to the original security xattrs (eg. security.selinux, + security.SMACK64, security.capability, and security.ima) included + in the HMAC calculation, enabling this option includes newly defined + Smack xattrs: security.SMACK64EXEC, security.SMACK64TRANSMUTE and + security.SMACK64MMAP. + + WARNING: changing the HMAC calculation method or adding + additional info to the calculation, requires existing EVM + labeled file systems to be relabeled. + +config EVM_ADD_XATTRS + bool "Add additional EVM extended attributes at runtime" + depends on EVM + default n + help + Allow userland to provide additional xattrs for HMAC calculation. + + When this option is enabled, root can add additional xattrs to the + list used by EVM by writing them into + /sys/kernel/security/integrity/evm/evm_xattrs. + +config EVM_LOAD_X509 + bool "Load an X509 certificate onto the '.evm' trusted keyring" + depends on EVM && INTEGRITY_TRUSTED_KEYRING + default n + help + Load an X509 certificate onto the '.evm' trusted keyring. + + This option enables X509 certificate loading from the kernel + onto the '.evm' trusted keyring. A public key can be used to + verify EVM integrity starting from the 'init' process. The + key must have digitalSignature usage set. + +config EVM_X509_PATH + string "EVM X509 certificate path" + depends on EVM_LOAD_X509 + default "/etc/keys/x509_evm.der" + help + This option defines X509 certificate path. -- cgit v1.3.1