[dm-devel] [PATCH] libmultipath: fix a memory leak in set_ble_device

lixiaokeng lixiaokeng at huawei.com
Tue Aug 11 07:18:39 UTC 2020


Hello Martin:
  Thanks for your reviews. I will modify this patch with your advice
and send it again.

On 2020/8/10 21:22, Martin Wilck wrote:
> Hello Lixiaokeng,
> 
> On Thu, 2020-07-30 at 21:27 +0800, lixiaokeng wrote:
>> Hi.
>>   I'm very sorry for subject mistake in first mail.
>>
>> In set_ble_device func, if blist is NULL or ble is NULL,
>> the vendor and product isn't free. We think it is not
>> reasonable that strdup(XXX) is used as set_ble_device
>> and store_ble functions' parameter.
>>
>> Here we call strdup() in store_ble and set_ble_device
>> functions and the string will be free if functions fail.
>> Because constant string like "sdb" will be their parameter,
>> char * is changed to const char *. This is base on
>> upstream-queue branch in openSUSE/multipath-tools.
>>
>> Here we have another question. We want to know which branch
>> is mainline in https://github.com/openSUSE/multipath-tools.
>> The master is not changed since two years ago. And we find
>> the ups/submit-2007 branch in mwilck/multipath-tools have
>> a great changes. Do you have a plan to merge it to openSUSE.
>>
>> Signed-off-by: Lixiaokeng <lixiaokeng at huawei.com>
>> Signed-off-by: Zhiqiang Liu <liuzhiqiang26 at huawei.com>
> 
> Thanks for the patch, it looks good. I have some minor formal issues
> below.
> 
> Regards,
> Martin
> 
> 
>>
>> ---
>>  libmultipath/blacklist.c | 74 +++++++++++++++++++++++---------------
>> --
>>  libmultipath/blacklist.h |  4 +--
>>  tests/blacklist.c        | 31 +++++++----------
>>  3 files changed, 58 insertions(+), 51 deletions(-)
>>
>> diff --git a/libmultipath/blacklist.c b/libmultipath/blacklist.c
>> index db58ccca..04aeb426 100644
>> --- a/libmultipath/blacklist.c
>> +++ b/libmultipath/blacklist.c
>> @@ -29,14 +29,19 @@ char *check_invert(char *str, bool *invert)
>>  	return str;
>>  }
>>
>> -int store_ble(vector blist, char * str, int origin)
>> +int store_ble(vector blist, const char * str, int origin)
> 
> Please use kernel formatting conventions for added code, i.e.
> "const char *str".
> 
>>  {
>>  	struct blentry * ble;
>>  	char *regex_str;
>> +	char *strdup_str = NULL;
>>
>>  	if (!str)
>>  		return 0;
>>
>> +	strdup_str = strdup(str);
>> +	if (!strdup_str)
>> +		return 1;
>> +
>>  	if (!blist)
>>  		goto out;
>>
>> @@ -45,21 +50,21 @@ int store_ble(vector blist, char * str, int
>> origin)
>>  	if (!ble)
>>  		goto out;
>>
>> -	regex_str = check_invert(str, &ble->invert);
>> +	regex_str = check_invert(strdup_str, &ble->invert);
>>  	if (regcomp(&ble->regex, regex_str, REG_EXTENDED|REG_NOSUB))
>>  		goto out1;
>>
>>  	if (!vector_alloc_slot(blist))
>>  		goto out1;
>>
>> -	ble->str = str;
>> +	ble->str = strdup_str;
>>  	ble->origin = origin;
>>  	vector_set_slot(blist, ble);
>>  	return 0;
>>  out1:
>>  	FREE(ble);
>>  out:
>> -	FREE(str);
>> +	FREE(strdup_str);
>>  	return 1;
>>  }
>>
>> @@ -79,10 +84,12 @@ int alloc_ble_device(vector blist)
>>  	return 0;
>>  }
>>
>> -int set_ble_device(vector blist, char * vendor, char * product, int
>> origin)
>> +int set_ble_device(vector blist, const char * vendor, const char *
>> product, int origin)
>>  {
>>  	struct blentry_device * ble;
>>  	char *regex_str;
>> +	char *vendor_str = NULL;
>> +	char *product_str = NULL;
>>
>>  	if (!blist)
>>  		return 1;
>> @@ -93,31 +100,42 @@ int set_ble_device(vector blist, char * vendor,
>> char * product, int origin)
>>  		return 1;
>>
>>  	if (vendor) {
>> -		regex_str = check_invert(vendor, &ble->vendor_invert);
>> +		vendor_str = STRDUP(vendor);
>> +		if (!vendor_str)
>> +			goto out;
>> +
>> +		regex_str = check_invert(vendor_str, &ble-
>>> vendor_invert);
>>  		if (regcomp(&ble->vendor_reg, regex_str,
>>  			    REG_EXTENDED|REG_NOSUB)) {
>> -			FREE(vendor);
>> -			if (product)
>> -				FREE(product);
>> -			return 1;
>> +			goto out;
>>  		}
>> -		ble->vendor = vendor;
>> +		ble->vendor = vendor_str;
>>  	}
>>  	if (product) {
>> -		regex_str = check_invert(product, &ble-
>>> product_invert);
>> +		product_str = STRDUP(product);
>> +		if (!product_str)
>> +			goto out1;
>> +
>> +		regex_str = check_invert(product_str, &ble-
>>> product_invert);
>>  		if (regcomp(&ble->product_reg, regex_str,
>>  			    REG_EXTENDED|REG_NOSUB)) {
>> -			FREE(product);
>> -			if (vendor) {
>> -				ble->vendor = NULL;
>> -				FREE(vendor);
>> -			}
>> -			return 1;
>> +			goto out1;
>>  		}
>> -		ble->product = product;
>> +		ble->product = product_str;
>>  	}
>>  	ble->origin = origin;
>>  	return 0;
>> +out1:
>> +	if (vendor_str)
>> +		ble->vendor = NULL;
>> +out:
>> +	if (vendor_str)
>> +		FREE(vendor_str);
>> +
>> +	if (product_str)
>> +		FREE(product_str);
> 
> These if's are superfluous; free() ignores NULL pointers. 
> Btw, while using FREE() here isn't wrong, I tend to not use it any
> more. IMO it's better to simply call free(), and set the pointer to
> NULL explicitly when necessary. multipath-tools builtin memory
> allocation debugging facility (dbg_free() etc) facility is obsolete, as
> valgrind etc. are far more powerful.
> 
>> +
>> +	return 1;
>>  }
>>
>>  static int
>> @@ -178,20 +196,16 @@ setup_default_blist (struct config * conf)
>>  {
>>  	struct blentry * ble;
>>  	struct hwentry *hwe;
>> -	char * str;
>>  	int i;
>>
>> -	str = STRDUP("!^(sd[a-z]|dasd[a-z]|nvme[0-9])");
>> -	if (!str)
>> -		return 1;
>> -	if (store_ble(conf->blist_devnode, str, ORIGIN_DEFAULT))
>> +	if (store_ble(conf->blist_devnode, "!^(sd[a-z]|dasd[a-
>> z]|nvme[0-9])"
>> +		, ORIGIN_DEFAULT)) {
>>  		return 1;
>> +	}
>>
>> -	str = STRDUP("(SCSI_IDENT_|ID_WWN)");
>> -	if (!str)
>> -		return 1;
>> -	if (store_ble(conf->elist_property, str, ORIGIN_DEFAULT))
>> +	if (store_ble(conf->elist_property, "(SCSI_IDENT_|ID_WWN)",
>> ORIGIN_DEFAULT)) {
>>  		return 1;
>> +	}
>>
>>  	vector_foreach_slot (conf->hwtable, hwe, i) {
>>  		if (hwe->bl_product) {
>> @@ -202,9 +216,7 @@ setup_default_blist (struct config * conf)
>>  				return 1;
>>  			ble = VECTOR_SLOT(conf->blist_device,
>>  					  VECTOR_SIZE(conf-
>>> blist_device) - 1);
>> -			if (set_ble_device(conf->blist_device,
>> -					   STRDUP(hwe->vendor),
>> -					   STRDUP(hwe->bl_product),
>> +			if (set_ble_device(conf->blist_device,hwe-
>>> vendor,hwe->bl_product,
>>  					   ORIGIN_DEFAULT)) {
>>  				FREE(ble);
>>  				vector_del_slot(conf->blist_device,
>> VECTOR_SIZE(conf->blist_device) - 1);
>> diff --git a/libmultipath/blacklist.h b/libmultipath/blacklist.h
>> index 4305857d..b08e0978 100644
>> --- a/libmultipath/blacklist.h
>> +++ b/libmultipath/blacklist.h
>> @@ -42,8 +42,8 @@ int filter_device (vector, vector, char *, char *,
>> char *);
>>  int filter_path (struct config *, struct path *);
>>  int filter_property(struct config *, struct udev_device *, int,
>> const char*);
>>  int filter_protocol(vector, vector, struct path *);
>> -int store_ble (vector, char *, int);
>> -int set_ble_device (vector, char *, char *, int);
>> +int store_ble (vector, const char *, int);
>> +int set_ble_device (vector, const char *, const char *, int);
>>  void free_blacklist (vector);
>>  void free_blacklist_device (vector);
>>  void merge_blacklist(vector);
>> diff --git a/tests/blacklist.c b/tests/blacklist.c
>> index d5c40898..84a3ba2f 100644
>> --- a/tests/blacklist.c
>> +++ b/tests/blacklist.c
>> @@ -94,67 +94,62 @@ static int setup(void **state)
>>
>>  	blist_devnode_sdb = vector_alloc();
>>  	if (!blist_devnode_sdb ||
>> -	    store_ble(blist_devnode_sdb, strdup("sdb"), ORIGIN_CONFIG))
>> +	    store_ble(blist_devnode_sdb, "sdb", ORIGIN_CONFIG))
>>  		return -1;
>>  	blist_devnode_sdb_inv = vector_alloc();
>>  	if (!blist_devnode_sdb_inv ||
>> -	    store_ble(blist_devnode_sdb_inv, strdup("!sdb"),
>> ORIGIN_CONFIG))
>> +	    store_ble(blist_devnode_sdb_inv, "!sdb", ORIGIN_CONFIG))
>>  		return -1;
>>
>>  	blist_all = vector_alloc();
>> -	if (!blist_all || store_ble(blist_all, strdup(".*"),
>> ORIGIN_CONFIG))
>> +	if (!blist_all || store_ble(blist_all, ".*", ORIGIN_CONFIG))
>>  		return -1;
>>
>>  	blist_device_foo_bar = vector_alloc();
>>  	if (!blist_device_foo_bar ||
>> alloc_ble_device(blist_device_foo_bar) ||
>> -	    set_ble_device(blist_device_foo_bar, strdup("foo"),
>> strdup("bar"),
>> -			   ORIGIN_CONFIG))
>> +	    set_ble_device(blist_device_foo_bar, "foo", "bar",
>> ORIGIN_CONFIG))
>>  		return -1;
>>  	blist_device_foo_inv_bar = vector_alloc();
>>  	if (!blist_device_foo_inv_bar ||
>>  	    alloc_ble_device(blist_device_foo_inv_bar) ||
>> -	    set_ble_device(blist_device_foo_inv_bar, strdup("!foo"),
>> -			   strdup("bar"), ORIGIN_CONFIG))
>> +	    set_ble_device(blist_device_foo_inv_bar, "!foo", "bar",
>> ORIGIN_CONFIG))
>>  		return -1;
>>  	blist_device_foo_bar_inv = vector_alloc();
>>  	if (!blist_device_foo_bar_inv ||
>>  	    alloc_ble_device(blist_device_foo_bar_inv) ||
>> -	    set_ble_device(blist_device_foo_bar_inv, strdup("foo"),
>> -			   strdup("!bar"), ORIGIN_CONFIG))
>> +	    set_ble_device(blist_device_foo_bar_inv, "foo", "!bar",
>> ORIGIN_CONFIG))
>>  		return -1;
>>
>>  	blist_device_all = vector_alloc();
>>  	if (!blist_device_all || alloc_ble_device(blist_device_all) ||
>> -	    set_ble_device(blist_device_all, strdup(".*"),
>> strdup(".*"),
>> -			   ORIGIN_CONFIG))
>> +	    set_ble_device(blist_device_all, ".*", ".*",
>> ORIGIN_CONFIG))
>>  		return -1;
>>
>>  	blist_wwid_xyzzy = vector_alloc();
>>  	if (!blist_wwid_xyzzy ||
>> -	    store_ble(blist_wwid_xyzzy, strdup("xyzzy"),
>> ORIGIN_CONFIG))
>> +	    store_ble(blist_wwid_xyzzy, "xyzzy", ORIGIN_CONFIG))
>>  		return -1;
>>  	blist_wwid_xyzzy_inv = vector_alloc();
>>  	if (!blist_wwid_xyzzy_inv ||
>> -	    store_ble(blist_wwid_xyzzy_inv, strdup("!xyzzy"),
>> ORIGIN_CONFIG))
>> +	    store_ble(blist_wwid_xyzzy_inv, "!xyzzy", ORIGIN_CONFIG))
>>  		return -1;
>>
>>  	blist_protocol_fcp = vector_alloc();
>>  	if (!blist_protocol_fcp ||
>> -	    store_ble(blist_protocol_fcp, strdup("scsi:fcp"),
>> ORIGIN_CONFIG))
>> +	    store_ble(blist_protocol_fcp, "scsi:fcp", ORIGIN_CONFIG))
>>  		return -1;
>>  	blist_protocol_fcp_inv = vector_alloc();
>>  	if (!blist_protocol_fcp_inv ||
>> -	    store_ble(blist_protocol_fcp_inv, strdup("!scsi:fcp"),
>> -		      ORIGIN_CONFIG))
>> +	    store_ble(blist_protocol_fcp_inv, "!scsi:fcp",
>> ORIGIN_CONFIG))
>>  		return -1;
>>
>>  	blist_property_wwn = vector_alloc();
>>  	if (!blist_property_wwn ||
>> -	    store_ble(blist_property_wwn, strdup("ID_WWN"),
>> ORIGIN_CONFIG))
>> +	    store_ble(blist_property_wwn, "ID_WWN", ORIGIN_CONFIG))
>>  		return -1;
>>  	blist_property_wwn_inv = vector_alloc();
>>  	if (!blist_property_wwn_inv ||
>> -	    store_ble(blist_property_wwn_inv, strdup("!ID_WWN"),
>> ORIGIN_CONFIG))
>> +	    store_ble(blist_property_wwn_inv, "!ID_WWN",
>> ORIGIN_CONFIG))
>>  		return -1;
>>
>>  	return 0;
> 
> 
> 
> .
> 




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