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/smb/client/smb1debug.c | 25 +++++++++++++++++++++++++ 1 file changed, 25 insertions(+) create mode 100644 fs/smb/client/smb1debug.c (limited to 'fs/smb/client/smb1debug.c') diff --git a/fs/smb/client/smb1debug.c b/fs/smb/client/smb1debug.c new file mode 100644 index 000000000..e2d013e75 --- /dev/null +++ b/fs/smb/client/smb1debug.c @@ -0,0 +1,25 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * + * Copyright (C) International Business Machines Corp., 2000,2005 + * + * Modified by Steve French (sfrench@us.ibm.com) + */ +#include "cifsproto.h" +#include "smb1proto.h" +#include "cifs_debug.h" + +void cifs_dump_detail(void *buf, size_t buf_len, struct TCP_Server_Info *server) +{ +#ifdef CONFIG_CIFS_DEBUG2 + struct smb_hdr *smb = buf; + + cifs_dbg(VFS, "Cmd: %d Err: 0x%x Flags: 0x%x Flgs2: 0x%x Mid: %d Pid: %d Wct: %d\n", + smb->Command, smb->Status.CifsError, smb->Flags, + smb->Flags2, smb->Mid, smb->Pid, smb->WordCount); + if (!server->ops->check_message(buf, buf_len, server->total_read, server)) { + cifs_dbg(VFS, "smb buf %p len %u\n", smb, + server->ops->calc_smb_size(smb)); + } +#endif /* CONFIG_CIFS_DEBUG2 */ +} -- cgit v1.3.1