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Commit adb00ae2 authored by Stephen Hemminger's avatar Stephen Hemminger Committed by Patrick McHardy
Browse files

netfilter: x_tables: misuse of try_then_request_module 



Since xt_find_match() returns ERR_PTR(xx) on error not NULL,
the macro try_then_request_module won't work correctly here.
The macro expects its first argument will be zero if condition
fails. But ERR_PTR(-ENOENT) is not zero.

The correct solution is to propagate the error value
back.

Found by inspection, and compile tested only.

Signed-off-by: default avatarStephen Hemminger <shemminger@vyatta.com>
Signed-off-by: default avatarPatrick McHardy <kaber@trash.net>
parent 9846ada1

net/netfilter/x_tables.c

+15 −7
Original line number Diff line number Diff line
@@ -183,7 +183,7 @@ EXPORT_SYMBOL(xt_unregister_matches); 
/*

 * These are weird, but module loading must not be done with mutex

 * held (since they will register), and we have to have a single

 * function to use try_then_request_module().

 * function to use.

 */



/* Find match, grabs ref.  Returns ERR_PTR() on error. */
@@ -221,9 +221,13 @@ xt_request_find_match(uint8_t nfproto, const char *name, uint8_t revision) 
{

	struct xt_match *match;



	match = try_then_request_module(xt_find_match(nfproto, name, revision),

					"%st_%s", xt_prefix[nfproto], name);

	return (match != NULL) ? match : ERR_PTR(-ENOENT);

	match = xt_find_match(nfproto, name, revision);

	if (IS_ERR(match)) {

		request_module("%st_%s", xt_prefix[nfproto], name);

		match = xt_find_match(nfproto, name, revision);

	}



	return match;

}

EXPORT_SYMBOL_GPL(xt_request_find_match);
@@ -261,9 +265,13 @@ struct xt_target *xt_request_find_target(u8 af, const char *name, u8 revision) 
{

	struct xt_target *target;



	target = try_then_request_module(xt_find_target(af, name, revision),

					 "%st_%s", xt_prefix[af], name);

	return (target != NULL) ? target : ERR_PTR(-ENOENT);

	target = xt_find_target(af, name, revision);

	if (IS_ERR(target)) {

		request_module("%st_%s", xt_prefix[af], name);

		target = xt_find_target(af, name, revision);

	}



	return target;

}

EXPORT_SYMBOL_GPL(xt_request_find_target);