Commit fcf88917 authored Apr 06, 2019 by Qian Cai Committed by Linus Torvalds Apr 07, 2019

slab: fix a crash by reading /proc/slab_allocators



The commit 510ded33 ("slab: implement slab_root_caches list")
changes the name of the list node within "struct kmem_cache" from "list"
to "root_caches_node", but leaks_show() still use the "list" which
causes a crash when reading /proc/slab_allocators.

You need to have CONFIG_SLAB=y and CONFIG_MEMCG=y to see the problem,
because without MEMCG all slab caches are root caches, and the "list"
node happens to be the right one.

Fixes: 510ded33 ("slab: implement slab_root_caches list")
Signed-off-by: Qian Cai <cai@lca.pw>
Reviewed-by: Tobin C. Harding <tobin@kernel.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent 15ade5d2

mm/slab.c

+2 −1

Original line number	Diff line number	Diff line
		@@ -4308,7 +4308,8 @@ static void show_symbol(struct seq_file *m, unsigned long address)

		static int leaks_show(struct seq_file m, void p)
		{
		struct kmem_cache *cachep = list_entry(p, struct kmem_cache, list);
		struct kmem_cache *cachep = list_entry(p, struct kmem_cache,
		root_caches_node);
		struct page *page;
		struct kmem_cache_node *n;
		const char *name;

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