Revision 7ff57e98fb78ad94edafbdc7435f2d745e9e6bb5 authored by Fabio M. De Francesco on 23 February 2022, 10:02:52 UTC, committed by Jakub Kicinski on 24 February 2022, 17:09:33 UTC
smc_pnetid_by_table_ib() uses read_lock() and then it calls smc_pnet_apply_ib()
which, in turn, calls mutex_lock(&smc_ib_devices.mutex).

read_lock() disables preemption. Therefore, the code acquires a mutex while in
atomic context and it leads to a SAC bug.

Fix this bug by replacing the rwlock with a mutex.

Reported-and-tested-by: syzbot+4f322a6d84e991c38775@syzkaller.appspotmail.com
Fixes: 64e28b52c7a6 ("net/smc: add pnet table namespace support")
Confirmed-by: Tony Lu <tonylu@linux.alibaba.com>
Signed-off-by: Fabio M. De Francesco <fmdefrancesco@gmail.com>
Acked-by: Karsten Graul <kgraul@linux.ibm.com>
Link: https://lore.kernel.org/r/20220223100252.22562-1-fmdefrancesco@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
1 parent e13ad14
Raw File
notifier-error-inject.h
/* SPDX-License-Identifier: GPL-2.0 */
#include <linux/atomic.h>
#include <linux/debugfs.h>
#include <linux/notifier.h>

struct notifier_err_inject_action {
	unsigned long val;
	int error;
	const char *name;
};

#define NOTIFIER_ERR_INJECT_ACTION(action)	\
	.name = #action, .val = (action),

struct notifier_err_inject {
	struct notifier_block nb;
	struct notifier_err_inject_action actions[];
	/* The last slot must be terminated with zero sentinel */
};

extern struct dentry *notifier_err_inject_dir;

extern struct dentry *notifier_err_inject_init(const char *name,
		struct dentry *parent, struct notifier_err_inject *err_inject,
		int priority);
back to top