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 --- fs/ext2/Kconfig | 50 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 50 insertions(+) create mode 100644 fs/ext2/Kconfig (limited to 'fs/ext2/Kconfig') diff --git a/fs/ext2/Kconfig b/fs/ext2/Kconfig new file mode 100644 index 000000000..d5bce83ad --- /dev/null +++ b/fs/ext2/Kconfig @@ -0,0 +1,50 @@ +# SPDX-License-Identifier: GPL-2.0-only +config EXT2_FS + tristate "Second extended fs support (DEPRECATED)" + select BUFFER_HEAD + select FS_IOMAP + help + Ext2 is a standard Linux file system for hard disks. + + This filesystem driver is deprecated because it does not properly + support inode time stamps beyond 03:14:07 UTC on 19 January 2038. + + Ext2 users are advised to use ext4 driver to access their filesystem. + The driver is fully compatible, supports filesystems without journal + or extents, and also supports larger time stamps if the filesystem + is created with at least 256 byte inodes. + + This code is kept as a simple reference for filesystem developers. + + If unsure, say N. + +config EXT2_FS_XATTR + bool "Ext2 extended attributes" + depends on EXT2_FS + help + Extended attributes are name:value pairs associated with inodes by + the kernel or by users (see the attr(5) manual page for details). + + If unsure, say N. + +config EXT2_FS_POSIX_ACL + bool "Ext2 POSIX Access Control Lists" + depends on EXT2_FS_XATTR + select FS_POSIX_ACL + help + Posix Access Control Lists (ACLs) support permissions for users and + groups beyond the owner/group/world scheme. + + If you don't know what Access Control Lists are, say N + +config EXT2_FS_SECURITY + bool "Ext2 Security Labels" + depends on EXT2_FS_XATTR + help + Security labels support alternative access control models + implemented by security modules like SELinux. This option + enables an extended attribute handler for file security + labels in the ext2 filesystem. + + If you are not using a security module that requires using + extended attributes for file security labels, say N. -- cgit v1.3.1