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/acl.h | 73 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 73 insertions(+) create mode 100644 fs/ext2/acl.h (limited to 'fs/ext2/acl.h') diff --git a/fs/ext2/acl.h b/fs/ext2/acl.h new file mode 100644 index 000000000..4a8443a2b --- /dev/null +++ b/fs/ext2/acl.h @@ -0,0 +1,73 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + File: fs/ext2/acl.h + + (C) 2001 Andreas Gruenbacher, +*/ + +#include + +#define EXT2_ACL_VERSION 0x0001 + +typedef struct { + __le16 e_tag; + __le16 e_perm; + __le32 e_id; +} ext2_acl_entry; + +typedef struct { + __le16 e_tag; + __le16 e_perm; +} ext2_acl_entry_short; + +typedef struct { + __le32 a_version; +} ext2_acl_header; + +static inline size_t ext2_acl_size(int count) +{ + if (count <= 4) { + return sizeof(ext2_acl_header) + + count * sizeof(ext2_acl_entry_short); + } else { + return sizeof(ext2_acl_header) + + 4 * sizeof(ext2_acl_entry_short) + + (count - 4) * sizeof(ext2_acl_entry); + } +} + +static inline int ext2_acl_count(size_t size) +{ + ssize_t s; + size -= sizeof(ext2_acl_header); + s = size - 4 * sizeof(ext2_acl_entry_short); + if (s < 0) { + if (size % sizeof(ext2_acl_entry_short)) + return -1; + return size / sizeof(ext2_acl_entry_short); + } else { + if (s % sizeof(ext2_acl_entry)) + return -1; + return s / sizeof(ext2_acl_entry) + 4; + } +} + +#ifdef CONFIG_EXT2_FS_POSIX_ACL + +/* acl.c */ +extern struct posix_acl *ext2_get_acl(struct inode *inode, int type, bool rcu); +extern int ext2_set_acl(struct mnt_idmap *idmap, struct dentry *dentry, + struct posix_acl *acl, int type); +extern int ext2_init_acl (struct inode *, struct inode *); + +#else +#include +#define ext2_get_acl NULL +#define ext2_set_acl NULL + +static inline int ext2_init_acl (struct inode *inode, struct inode *dir) +{ + return 0; +} +#endif + -- cgit v1.3.1