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/jffs2/security.c | 73 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 73 insertions(+) create mode 100644 fs/jffs2/security.c (limited to 'fs/jffs2/security.c') diff --git a/fs/jffs2/security.c b/fs/jffs2/security.c new file mode 100644 index 000000000..437f3a2c1 --- /dev/null +++ b/fs/jffs2/security.c @@ -0,0 +1,73 @@ +/* + * JFFS2 -- Journalling Flash File System, Version 2. + * + * Copyright © 2006 NEC Corporation + * + * Created by KaiGai Kohei + * + * For licensing information, see the file 'LICENCE' in this directory. + * + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include "nodelist.h" + +/* ---- Initial Security Label(s) Attachment callback --- */ +static int jffs2_initxattrs(struct inode *inode, + const struct xattr *xattr_array, void *fs_info) +{ + const struct xattr *xattr; + int err = 0; + + for (xattr = xattr_array; xattr->name != NULL; xattr++) { + err = do_jffs2_setxattr(inode, JFFS2_XPREFIX_SECURITY, + xattr->name, xattr->value, + xattr->value_len, 0); + if (err < 0) + break; + } + return err; +} + +/* ---- Initial Security Label(s) Attachment ----------- */ +int jffs2_init_security(struct inode *inode, struct inode *dir, + const struct qstr *qstr) +{ + return security_inode_init_security(inode, dir, qstr, + &jffs2_initxattrs, NULL); +} + +/* ---- XATTR Handler for "security.*" ----------------- */ +static int jffs2_security_getxattr(const struct xattr_handler *handler, + struct dentry *unused, struct inode *inode, + const char *name, void *buffer, size_t size) +{ + return do_jffs2_getxattr(inode, JFFS2_XPREFIX_SECURITY, + name, buffer, size); +} + +static int jffs2_security_setxattr(const struct xattr_handler *handler, + struct mnt_idmap *idmap, + struct dentry *unused, struct inode *inode, + const char *name, const void *buffer, + size_t size, int flags) +{ + return do_jffs2_setxattr(inode, JFFS2_XPREFIX_SECURITY, + name, buffer, size, flags); +} + +const struct xattr_handler jffs2_security_xattr_handler = { + .prefix = XATTR_SECURITY_PREFIX, + .set = jffs2_security_setxattr, + .get = jffs2_security_getxattr +}; -- cgit v1.3.1