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/fuse/Kconfig | 78 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 78 insertions(+) create mode 100644 fs/fuse/Kconfig (limited to 'fs/fuse/Kconfig') diff --git a/fs/fuse/Kconfig b/fs/fuse/Kconfig new file mode 100644 index 000000000..3a4ae632c --- /dev/null +++ b/fs/fuse/Kconfig @@ -0,0 +1,78 @@ +# SPDX-License-Identifier: GPL-2.0-only +config FUSE_FS + tristate "FUSE (Filesystem in Userspace) support" + select FS_POSIX_ACL + select FS_IOMAP + help + With FUSE it is possible to implement a fully functional filesystem + in a userspace program. + + There's also a companion library: libfuse2. This library is available + from the FUSE homepage: + + although chances are your distribution already has that library + installed if you've installed the "fuse" package itself. + + See for more information. + See for needed library/utility version. + + If you want to develop a userspace FS, or if you want to use + a filesystem based on FUSE, answer Y or M. + +config CUSE + tristate "Character device in Userspace support" + depends on FUSE_FS + help + This FUSE extension allows character devices to be + implemented in userspace. + + If you want to develop or use a userspace character device + based on CUSE, answer Y or M. + +config VIRTIO_FS + tristate "Virtio Filesystem" + depends on FUSE_FS + select VIRTIO + help + The Virtio Filesystem allows guests to mount file systems from the + host. + + If you want to share files between guests or with the host, answer Y + or M. + +config FUSE_DAX + bool "Virtio Filesystem Direct Host Memory Access support" + default y + select INTERVAL_TREE + depends on VIRTIO_FS + depends on FS_DAX + depends on DAX + help + This allows bypassing guest page cache and allows mapping host page + cache directly in guest address space. + + If you want to allow mounting a Virtio Filesystem with the "dax" + option, answer Y. + +config FUSE_PASSTHROUGH + bool "FUSE passthrough operations support" + default y + depends on FUSE_FS + select FS_STACK + help + This allows bypassing FUSE server by mapping specific FUSE operations + to be performed directly on a backing file. + + If you want to allow passthrough operations, answer Y. + +config FUSE_IO_URING + bool "FUSE communication over io-uring" + default y + depends on FUSE_FS + depends on IO_URING + help + This allows sending FUSE requests over the io-uring interface and + also adds request core affinity. + + If you want to allow fuse server/client communication through io-uring, + answer Y -- cgit v1.3.1