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/nilfs2/export.h | 26 ++++++++++++++++++++++++++ 1 file changed, 26 insertions(+) create mode 100644 fs/nilfs2/export.h (limited to 'fs/nilfs2/export.h') diff --git a/fs/nilfs2/export.h b/fs/nilfs2/export.h new file mode 100644 index 000000000..d29fd837c --- /dev/null +++ b/fs/nilfs2/export.h @@ -0,0 +1,26 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef NILFS_EXPORT_H +#define NILFS_EXPORT_H + +#include + +extern const struct export_operations nilfs_export_ops; + +/** + * struct nilfs_fid - NILFS file id type + * @cno: checkpoint number + * @ino: inode number + * @gen: file generation (version) for NFS + * @parent_gen: parent generation (version) for NFS + * @parent_ino: parent inode number + */ +struct nilfs_fid { + u64 cno; + u64 ino; + u32 gen; + + u32 parent_gen; + u64 parent_ino; +} __packed; + +#endif -- cgit v1.3.1