Commit 37171e3c authored Aug 20, 2013 by Seth Jennings Committed by Greg Kroah-Hartman Aug 21, 2013

drivers: base: remove improper get/put in add_memory_section()



The path through add_memory_section() when the memory block already
exists uses flawed refcounting logic.  A get_device() is done on a
memory block using a pointer that might not be valid as we dropped
our previous reference and didn't obtain a new reference in the
proper way.

Lets stop pretending and just remove the get/put.  The
mem_sysfs_mutex, which we hold over the entire init loop now, will
prevent the memory blocks from disappearing from under us.

Signed-off-by: Seth Jennings <sjenning@linux.vnet.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent 37a7bd62

drivers/base/memory.c

+2 −4

Original line number	Diff line number	Diff line
		@@ -613,14 +613,12 @@ static int add_memory_section(struct mem_section *section,
		if (scn_nr >= (*mem_p)->start_section_nr &&
		scn_nr <= (*mem_p)->end_section_nr) {
		mem = *mem_p;
		get_device(&mem->dev);
		}
		}

		if (mem) {
		if (mem)
		mem->section_count++;
		put_device(&mem->dev);
		} else {
		else {
		ret = init_memory_block(&mem, section, MEM_ONLINE);
		/* store memory_block pointer for next loop */
		if (!ret && mem_p)