bcache: check return value from btree_node_alloc_replacement()

stable inclusion
from stable-v6.6.4
commit 30ed07af096eb32eb4a62e542933b086457bd616
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I8N1WC

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=30ed07af096eb32eb4a62e542933b086457bd616



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commit 777967e7e9f6f5f3e153abffb562bffaf4430d26 upstream.

In btree_gc_rewrite_node(), pointer 'n' is not checked after it returns
from btree_gc_rewrite_node(). There is potential possibility that 'n' is
a non NULL ERR_PTR(), referencing such error code is not permitted in
following code. Therefore a return value checking is necessary after 'n'
is back from btree_node_alloc_replacement().

Signed-off-by: Coly Li <colyli@suse.de>
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Cc:  <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20231120052503.6122-3-colyli@suse.de


Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>