linux-stable/net/smc/smc_pnet.h
Fabio M. De Francesco 7ff57e98fb net/smc: Use a mutex for locking "struct smc_pnettable"
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: 64e28b52c7 ("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>
2022-02-24 09:09:33 -08:00

70 lines
1.7 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
/*
* Shared Memory Communications over RDMA (SMC-R) and RoCE
*
* PNET table queries
*
* Copyright IBM Corp. 2016
*
* Author(s): Thomas Richter <tmricht@linux.vnet.ibm.com>
*/
#ifndef _SMC_PNET_H
#define _SMC_PNET_H
#include <net/smc.h>
#if IS_ENABLED(CONFIG_HAVE_PNETID)
#include <asm/pnet.h>
#endif
struct smc_ib_device;
struct smcd_dev;
struct smc_init_info;
struct smc_link_group;
/**
* struct smc_pnettable - SMC PNET table anchor
* @lock: Lock for list action
* @pnetlist: List of PNETIDs
*/
struct smc_pnettable {
struct mutex lock;
struct list_head pnetlist;
};
struct smc_pnetids_ndev { /* list of pnetids for net devices in UP state*/
struct list_head list;
rwlock_t lock;
};
struct smc_pnetids_ndev_entry {
struct list_head list;
u8 pnetid[SMC_MAX_PNETID_LEN];
refcount_t refcnt;
};
static inline int smc_pnetid_by_dev_port(struct device *dev,
unsigned short port, u8 *pnetid)
{
#if IS_ENABLED(CONFIG_HAVE_PNETID)
return pnet_id_by_dev_port(dev, port, pnetid);
#else
return -ENOENT;
#endif
}
int smc_pnet_init(void) __init;
int smc_pnet_net_init(struct net *net);
void smc_pnet_exit(void);
void smc_pnet_net_exit(struct net *net);
void smc_pnet_find_roce_resource(struct sock *sk, struct smc_init_info *ini);
void smc_pnet_find_ism_resource(struct sock *sk, struct smc_init_info *ini);
int smc_pnetid_by_table_ib(struct smc_ib_device *smcibdev, u8 ib_port);
int smc_pnetid_by_table_smcd(struct smcd_dev *smcd);
void smc_pnet_find_alt_roce(struct smc_link_group *lgr,
struct smc_init_info *ini,
struct smc_ib_device *known_dev);
bool smc_pnet_is_ndev_pnetid(struct net *net, u8 *pnetid);
bool smc_pnet_is_pnetid_set(u8 *pnetid);
#endif