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/hfsplus/xattr_security.c | 79 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 79 insertions(+) create mode 100644 fs/hfsplus/xattr_security.c (limited to 'fs/hfsplus/xattr_security.c') diff --git a/fs/hfsplus/xattr_security.c b/fs/hfsplus/xattr_security.c new file mode 100644 index 000000000..90f68ec11 --- /dev/null +++ b/fs/hfsplus/xattr_security.c @@ -0,0 +1,79 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * linux/fs/hfsplus/xattr_trusted.c + * + * Vyacheslav Dubeyko + * + * Handler for storing security labels as extended attributes. + */ + +#include +#include + +#include "hfsplus_fs.h" +#include "xattr.h" + +static int hfsplus_security_getxattr(const struct xattr_handler *handler, + struct dentry *unused, struct inode *inode, + const char *name, void *buffer, size_t size) +{ + return hfsplus_getxattr(inode, name, buffer, size, + XATTR_SECURITY_PREFIX, + XATTR_SECURITY_PREFIX_LEN); +} + +static int hfsplus_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 hfsplus_setxattr(inode, name, buffer, size, flags, + XATTR_SECURITY_PREFIX, + XATTR_SECURITY_PREFIX_LEN); +} + +static int hfsplus_initxattrs(struct inode *inode, + const struct xattr *xattr_array, + void *fs_info) +{ + const struct xattr *xattr; + char *xattr_name; + int err = 0; + + xattr_name = kmalloc(NLS_MAX_CHARSET_SIZE * HFSPLUS_ATTR_MAX_STRLEN + 1, + GFP_KERNEL); + if (!xattr_name) + return -ENOMEM; + for (xattr = xattr_array; xattr->name != NULL; xattr++) { + + if (!strcmp(xattr->name, "")) + continue; + + strcpy(xattr_name, XATTR_SECURITY_PREFIX); + strcpy(xattr_name + + XATTR_SECURITY_PREFIX_LEN, xattr->name); + memset(xattr_name + + XATTR_SECURITY_PREFIX_LEN + strlen(xattr->name), 0, 1); + + err = __hfsplus_setxattr(inode, xattr_name, + xattr->value, xattr->value_len, 0); + if (err) + break; + } + kfree(xattr_name); + return err; +} + +int hfsplus_init_security(struct inode *inode, struct inode *dir, + const struct qstr *qstr) +{ + return security_inode_init_security(inode, dir, qstr, + &hfsplus_initxattrs, NULL); +} + +const struct xattr_handler hfsplus_xattr_security_handler = { + .prefix = XATTR_SECURITY_PREFIX, + .get = hfsplus_security_getxattr, + .set = hfsplus_security_setxattr, +}; -- cgit v1.3.1