The patch below does not apply to the 4.14-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable@xxxxxxxxxxxxxxx>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-4.14.y git checkout FETCH_HEAD git cherry-pick -x 80fca8a10b604afad6c14213fdfd816c4eda3ee4 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable@xxxxxxxxxxxxxxx>' --in-reply-to '2023071622-crablike-glaucoma-f28c@gregkh' --subject-prefix 'PATCH 4.14.y' HEAD^.. Possible dependencies: 80fca8a10b60 ("bcache: Fix __bch_btree_node_alloc to make the failure behavior consistent") 17e4aed8309f ("bcache: remove 'int n' from parameter list of bch_bucket_alloc_set()") 8792099f9ad4 ("bcache: use MAX_CACHES_PER_SET instead of magic number 8 in __bch_bucket_alloc_set") fc2d5988b597 ("bcache: add identifier names to arguments of function definitions") 6f10f7d1b02b ("bcache: style fix to replace 'unsigned' by 'unsigned int'") ea8c5356d390 ("bcache: set max writeback rate when I/O request is idle") b467a6ac0b4b ("bcache: add code comments for bset.c") b4cb6efc1af7 ("bcache: display rate debug parameters to 0 when writeback is not running") 94f71c16062e ("bcache: fix I/O significant decline while backend devices registering") 99a27d59bd7b ("bcache: simplify the calculation of the total amount of flash dirty data") ddcf35d39797 ("block: Add and use op_stat_group() for indexing disk_stat fields.") 3f289dcb4b26 ("block: make bdev_ops->rw_page() take a REQ_OP instead of bool") 0f0709e6bfc3 ("bcache: stop bcache device when backing device is offline") 522a777566f5 ("block: consolidate struct request timestamp fields") 4bc6339a583c ("block: move blk_stat_add() to __blk_mq_end_request()") 84c7afcebed9 ("block: use ktime_get_ns() instead of sched_clock() for cfq and bfq") 544ccc8dc904 ("block: get rid of struct blk_issue_stat") a8a45941706b ("block: pass struct request instead of struct blk_issue_stat to wbt") 934031a12980 ("block: move some wbt helpers to blk-wbt.c") 782f569774d7 ("blk-wbt: throttle discards like background writes") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 80fca8a10b604afad6c14213fdfd816c4eda3ee4 Mon Sep 17 00:00:00 2001 From: Zheng Wang <zyytlz.wz@xxxxxxx> Date: Thu, 15 Jun 2023 20:12:22 +0800 Subject: [PATCH] bcache: Fix __bch_btree_node_alloc to make the failure behavior consistent In some specific situations, the return value of __bch_btree_node_alloc may be NULL. This may lead to a potential NULL pointer dereference in caller function like a calling chain : btree_split->bch_btree_node_alloc->__bch_btree_node_alloc. Fix it by initializing the return value in __bch_btree_node_alloc. Fixes: cafe56359144 ("bcache: A block layer cache") Cc: stable@xxxxxxxxxxxxxxx Signed-off-by: Zheng Wang <zyytlz.wz@xxxxxxx> Signed-off-by: Coly Li <colyli@xxxxxxx> Link: https://lore.kernel.org/r/20230615121223.22502-6-colyli@xxxxxxx Signed-off-by: Jens Axboe <axboe@xxxxxxxxx> diff --git a/drivers/md/bcache/btree.c b/drivers/md/bcache/btree.c index 7c21e54468bf..0ddf91204782 100644 --- a/drivers/md/bcache/btree.c +++ b/drivers/md/bcache/btree.c @@ -1090,10 +1090,12 @@ struct btree *__bch_btree_node_alloc(struct cache_set *c, struct btree_op *op, struct btree *parent) { BKEY_PADDED(key) k; - struct btree *b = ERR_PTR(-EAGAIN); + struct btree *b; mutex_lock(&c->bucket_lock); retry: + /* return ERR_PTR(-EAGAIN) when it fails */ + b = ERR_PTR(-EAGAIN); if (__bch_bucket_alloc_set(c, RESERVE_BTREE, &k.key, wait)) goto err;
