5.4-stable review patch. If anyone has any objections, please let me know.
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From: Liequan Che cheliequan@inspur.com
commit b2e382ae12a63560fca35050498e19e760adf8c0 upstream.
Commit 028ddcac477b ("bcache: Remove unnecessary NULL point check in node allocations") leads a NULL pointer deference in cache_set_flush().
1721 if (!IS_ERR_OR_NULL(c->root)) 1722 list_add(&c->root->list, &c->btree_cache);
From the above code in cache_set_flush(), if previous registration code
fails before allocating c->root, it is possible c->root is NULL as what it is initialized. __bch_btree_node_alloc() never returns NULL but c->root is possible to be NULL at above line 1721.
This patch replaces IS_ERR() by IS_ERR_OR_NULL() to fix this.
Fixes: 028ddcac477b ("bcache: Remove unnecessary NULL point check in node allocations") Signed-off-by: Liequan Che cheliequan@inspur.com Cc: stable@vger.kernel.org Cc: Zheng Wang zyytlz.wz@163.com Reviewed-by: Mingzhe Zou mingzhe.zou@easystack.cn Signed-off-by: Coly Li colyli@suse.de Link: https://lore.kernel.org/r/20241202115638.28957-1-colyli@suse.de Signed-off-by: Jens Axboe axboe@kernel.dk Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/md/bcache/super.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/drivers/md/bcache/super.c +++ b/drivers/md/bcache/super.c @@ -1635,7 +1635,7 @@ static void cache_set_flush(struct closu if (!IS_ERR_OR_NULL(c->gc_thread)) kthread_stop(c->gc_thread);
- if (!IS_ERR(c->root)) + if (!IS_ERR_OR_NULL(c->root)) list_add(&c->root->list, &c->btree_cache);
/*