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/lockd/xdr.h | 85 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 85 insertions(+) create mode 100644 fs/lockd/xdr.h (limited to 'fs/lockd/xdr.h') diff --git a/fs/lockd/xdr.h b/fs/lockd/xdr.h new file mode 100644 index 000000000..a1126cca9 --- /dev/null +++ b/fs/lockd/xdr.h @@ -0,0 +1,85 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * XDR types for the NLM protocol + * + * Copyright (C) 1996 Olaf Kirch + */ + +#ifndef _LOCKD_XDR_H +#define _LOCKD_XDR_H + +#include +#include +#include +#include + +#define SM_MAXSTRLEN 1024 +#define SM_PRIV_SIZE 16 + +struct nsm_private { + unsigned char data[SM_PRIV_SIZE]; +}; + +#define NLM_MAXCOOKIELEN 32 +#define NLM_MAXSTRLEN 1024 + +#define nlm_granted cpu_to_be32(NLM_LCK_GRANTED) +#define nlm_lck_denied cpu_to_be32(NLM_LCK_DENIED) +#define nlm_lck_denied_nolocks cpu_to_be32(NLM_LCK_DENIED_NOLOCKS) +#define nlm_lck_blocked cpu_to_be32(NLM_LCK_BLOCKED) +#define nlm_lck_denied_grace_period cpu_to_be32(NLM_LCK_DENIED_GRACE_PERIOD) + +/* Lock info passed via NLM */ +struct lockd_lock { + char * caller; + unsigned int len; /* length of "caller" */ + struct nfs_fh fh; + struct xdr_netobj oh; + u32 svid; + u64 lock_start; + u64 lock_len; + struct file_lock fl; +}; + +/* + * NLM cookies. Technically they can be 1K, but Linux only uses 8 bytes. + * FreeBSD uses 16, Apple Mac OS X 10.3 uses 20. Therefore we set it to + * 32 bytes. + */ + +struct lockd_cookie { + unsigned char data[NLM_MAXCOOKIELEN]; + unsigned int len; +}; + +/* + * Generic lockd arguments for all but sm_notify + */ +struct lockd_args { + struct lockd_cookie cookie; + struct lockd_lock lock; + u32 block; + u32 reclaim; + u32 state; +}; + +/* + * Generic lockd result + */ +struct lockd_res { + struct lockd_cookie cookie; + __be32 status; + struct lockd_lock lock; +}; + +/* + * statd callback when client has rebooted + */ +struct lockd_reboot { + char *mon; + unsigned int len; + u32 state; + struct nsm_private priv; +}; + +#endif /* _LOCKD_XDR_H */ -- cgit v1.3.1