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 --- include/sound/seq_oss.h | 83 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 83 insertions(+) create mode 100644 include/sound/seq_oss.h (limited to 'include/sound/seq_oss.h') diff --git a/include/sound/seq_oss.h b/include/sound/seq_oss.h new file mode 100644 index 000000000..7bf10a0fa --- /dev/null +++ b/include/sound/seq_oss.h @@ -0,0 +1,83 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +#ifndef __SOUND_SEQ_OSS_H +#define __SOUND_SEQ_OSS_H + +/* + * OSS compatible sequencer driver + * + * Copyright (C) 1998,99 Takashi Iwai + */ + +#include +#include + +/* + * argument structure for synthesizer operations + */ +struct snd_seq_oss_arg { + /* given by OSS sequencer */ + int app_index; /* application unique index */ + int file_mode; /* file mode - see below */ + int seq_mode; /* sequencer mode - see below */ + + /* following must be initialized in open callback */ + struct snd_seq_addr addr; /* opened port address */ + void *private_data; /* private data for lowlevel drivers */ + + /* note-on event passing mode: initially given by OSS seq, + * but configurable by drivers - see below + */ + int event_passing; +}; + + +/* + * synthesizer operation callbacks + */ +struct snd_seq_oss_callback { + struct module *owner; + int (*open)(struct snd_seq_oss_arg *p, void *closure); + int (*close)(struct snd_seq_oss_arg *p); + int (*ioctl)(struct snd_seq_oss_arg *p, unsigned int cmd, unsigned long arg); + int (*load_patch)(struct snd_seq_oss_arg *p, int format, const char __user *buf, int offs, int count); + int (*reset)(struct snd_seq_oss_arg *p); + int (*raw_event)(struct snd_seq_oss_arg *p, unsigned char *data); +}; + +/* flag: file_mode */ +#define SNDRV_SEQ_OSS_FILE_ACMODE 3 +#define SNDRV_SEQ_OSS_FILE_READ 1 +#define SNDRV_SEQ_OSS_FILE_WRITE 2 +#define SNDRV_SEQ_OSS_FILE_NONBLOCK 4 + +/* flag: seq_mode */ +#define SNDRV_SEQ_OSS_MODE_SYNTH 0 +#define SNDRV_SEQ_OSS_MODE_MUSIC 1 + +/* flag: event_passing */ +#define SNDRV_SEQ_OSS_PROCESS_EVENTS 0 /* key == 255 is processed as velocity change */ +#define SNDRV_SEQ_OSS_PASS_EVENTS 1 /* pass all events to callback */ +#define SNDRV_SEQ_OSS_PROCESS_KEYPRESS 2 /* key >= 128 will be processed as key-pressure */ + +/* default control rate: fixed */ +#define SNDRV_SEQ_OSS_CTRLRATE 100 + +/* default max queue length: configurable by module option */ +#define SNDRV_SEQ_OSS_MAX_QLEN 1024 + + +/* + * data pointer to snd_seq_register_device + */ +struct snd_seq_oss_reg { + int type; + int subtype; + int nvoices; + struct snd_seq_oss_callback oper; + void *private_data; +}; + +/* device id */ +#define SNDRV_SEQ_DEV_ID_OSS "seq-oss" + +#endif /* __SOUND_SEQ_OSS_H */ -- cgit v1.3.1