forked from mirrors/linux
		
	 7ff57e98fb
			
		
	
	
		7ff57e98fb
		
	
	
	
	
		
			
			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>
		
	
			
		
			
				
	
	
		
			70 lines
		
	
	
	
		
			1.7 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			70 lines
		
	
	
	
		
			1.7 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /* SPDX-License-Identifier: GPL-2.0 */
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| /*
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|  * Shared Memory Communications over RDMA (SMC-R) and RoCE
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|  *
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|  *  PNET table queries
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|  *
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|  *  Copyright IBM Corp. 2016
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|  *
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|  *  Author(s):  Thomas Richter <tmricht@linux.vnet.ibm.com>
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|  */
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| 
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| #ifndef _SMC_PNET_H
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| #define _SMC_PNET_H
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| 
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| #include <net/smc.h>
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| 
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| #if IS_ENABLED(CONFIG_HAVE_PNETID)
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| #include <asm/pnet.h>
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| #endif
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| 
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| struct smc_ib_device;
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| struct smcd_dev;
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| struct smc_init_info;
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| struct smc_link_group;
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| 
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| /**
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|  * struct smc_pnettable - SMC PNET table anchor
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|  * @lock: Lock for list action
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|  * @pnetlist: List of PNETIDs
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|  */
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| struct smc_pnettable {
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| 	struct mutex lock;
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| 	struct list_head pnetlist;
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| };
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| 
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| struct smc_pnetids_ndev {	/* list of pnetids for net devices in UP state*/
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| 	struct list_head	list;
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| 	rwlock_t		lock;
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| };
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| 
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| struct smc_pnetids_ndev_entry {
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| 	struct list_head	list;
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| 	u8			pnetid[SMC_MAX_PNETID_LEN];
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| 	refcount_t		refcnt;
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| };
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| 
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| static inline int smc_pnetid_by_dev_port(struct device *dev,
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| 					 unsigned short port, u8 *pnetid)
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| {
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| #if IS_ENABLED(CONFIG_HAVE_PNETID)
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| 	return pnet_id_by_dev_port(dev, port, pnetid);
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| #else
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| 	return -ENOENT;
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| #endif
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| }
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| 
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| int smc_pnet_init(void) __init;
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| int smc_pnet_net_init(struct net *net);
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| void smc_pnet_exit(void);
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| void smc_pnet_net_exit(struct net *net);
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| void smc_pnet_find_roce_resource(struct sock *sk, struct smc_init_info *ini);
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| void smc_pnet_find_ism_resource(struct sock *sk, struct smc_init_info *ini);
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| int smc_pnetid_by_table_ib(struct smc_ib_device *smcibdev, u8 ib_port);
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| int smc_pnetid_by_table_smcd(struct smcd_dev *smcd);
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| void smc_pnet_find_alt_roce(struct smc_link_group *lgr,
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| 			    struct smc_init_info *ini,
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| 			    struct smc_ib_device *known_dev);
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| bool smc_pnet_is_ndev_pnetid(struct net *net, u8 *pnetid);
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| bool smc_pnet_is_pnetid_set(u8 *pnetid);
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| #endif
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