From: Christophe JAILLET <christophe.jaillet@wanadoo.fr> stable inclusion from stable-v5.10.121 commit 49a5b1735cd9c26da29dd8cad79202421e62faba category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I5L6CQ Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- [ Upstream commit f47f758cff59c68015d6b9b9c077110df7c2c828 ] __add_memory_block() calls both put_device() and device_unregister() when storing the memory block into the xarray. This is incorrect because xarray doesn't take an additional reference and device_unregister() already calls put_device(). Triggering the issue looks really unlikely and its only effect should be to log a spurious warning about a ref counted issue. Link: https://lkml.kernel.org/r/d44c63d78affe844f020dc02ad6af29abc448fc4.165061170... Fixes: 4fb6eabf1037 ("drivers/base/memory.c: cache memory blocks in xarray to accelerate lookup") Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr> Acked-by: Michal Hocko <mhocko@suse.com> Reviewed-by: David Hildenbrand <david@redhat.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: "Rafael J. Wysocki" <rafael@kernel.org> Cc: Scott Cheloha <cheloha@linux.vnet.ibm.com> Cc: Nathan Lynch <nathanl@linux.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com> Acked-by: Xie XiuQi <xiexiuqi@huawei.com> --- drivers/base/memory.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/drivers/base/memory.c b/drivers/base/memory.c index de058d15b33e..49eb14271f28 100644 --- a/drivers/base/memory.c +++ b/drivers/base/memory.c @@ -560,10 +560,9 @@ int register_memory(struct memory_block *memory) } ret = xa_err(xa_store(&memory_blocks, memory->dev.id, memory, GFP_KERNEL)); - if (ret) { - put_device(&memory->dev); + if (ret) device_unregister(&memory->dev); - } + return ret; } -- 2.20.1