From: colyli@suse.de
To: axboe@kernel.dk
Cc: linux-bcache@vger.kernel.org, linux-block@vger.kernel.org,
Coly Li <colyli@suse.de>
Subject: [PATCH 04/17] bcache: properly initialize 'path' and 'err' in register_bcache()
Date: Fri, 24 Jan 2020 01:01:29 +0800 [thread overview]
Message-ID: <20200123170142.98974-5-colyli@suse.de> (raw)
In-Reply-To: <20200123170142.98974-1-colyli@suse.de>
From: Coly Li <colyli@suse.de>
Patch "bcache: rework error unwinding in register_bcache" from
Christoph Hellwig changes the local variables 'path' and 'err'
in undefined initial state. If the code in register_bcache() jumps
to label 'out:' or 'out_module_put:' by goto, these two variables
might be reference with undefined value by the following line,
out_module_put:
module_put(THIS_MODULE);
out:
pr_info("error %s: %s", path, err);
return ret;
Therefore this patch initializes these two local variables properly
in register_bcache() to avoid such issue.
Signed-off-by: Coly Li <colyli@suse.de>
---
drivers/md/bcache/super.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/md/bcache/super.c b/drivers/md/bcache/super.c
index e8013e1b0a14..ee7c87f38d0d 100644
--- a/drivers/md/bcache/super.c
+++ b/drivers/md/bcache/super.c
@@ -2376,18 +2376,20 @@ static ssize_t register_bcache(struct kobject *k, struct kobj_attribute *attr,
const char *buffer, size_t size)
{
const char *err;
- char *path;
+ char *path = NULL;
struct cache_sb *sb;
struct block_device *bdev = NULL;
struct page *sb_page;
ssize_t ret;
ret = -EBUSY;
+ err = "failed to reference bcache module";
if (!try_module_get(THIS_MODULE))
goto out;
/* For latest state of bcache_is_reboot */
smp_mb();
+ err = "bcache is in reboot";
if (bcache_is_reboot)
goto out_module_put;
--
2.16.4
next prev parent reply other threads:[~2020-01-23 17:02 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-01-23 17:01 [PATCH 00/17] bcache patches for Linux v5.6 colyli
2020-01-23 17:01 ` [PATCH 01/17] bcache: cached_dev_free needs to put the sb page colyli
2020-01-23 17:01 ` [PATCH 02/17] bcache: use a separate data structure for the on-disk super block colyli
2020-01-23 17:01 ` [PATCH 03/17] bcache: rework error unwinding in register_bcache colyli
2020-01-23 17:01 ` colyli [this message]
2020-01-23 17:01 ` [PATCH 05/17] bcache: fix use-after-free in register_bcache() colyli
2020-01-23 17:01 ` [PATCH 06/17] bcache: transfer the sb_page reference to register_{bdev,cache} colyli
2020-01-23 17:01 ` [PATCH 07/17] bcache: return a pointer to the on-disk sb from read_super colyli
2020-01-23 17:01 ` [PATCH 08/17] bcache: store a pointer to the on-disk sb in the cache and cached_dev structures colyli
2020-01-23 17:01 ` [PATCH 09/17] bcache: use read_cache_page_gfp to read the superblock colyli
2020-01-23 17:01 ` [PATCH 10/17] lib: crc64: include <linux/crc64.h> for 'crc64_be' colyli
2020-01-23 17:01 ` [PATCH 11/17] bcache: add code comments for state->pool in __btree_sort() colyli
2020-01-23 17:01 ` [PATCH 12/17] bcache: avoid unnecessary btree nodes flushing in btree_flush_write() colyli
2020-01-23 17:01 ` [PATCH 13/17] bcache: print written and keys in trace_bcache_btree_write colyli
2020-01-23 17:01 ` [PATCH 14/17] bcache: back to cache all readahead I/Os colyli
2020-01-23 17:19 ` Michael Lyle
2020-01-23 17:27 ` Coly Li
2020-01-23 18:31 ` Jens Axboe
2020-01-24 0:49 ` Coly Li
2020-01-24 1:14 ` Jens Axboe
2020-01-24 16:48 ` Michael Lyle
2020-01-23 17:01 ` [PATCH 15/17] bcache: remove member accessed from struct btree colyli
2020-01-23 17:01 ` [PATCH 16/17] bcache: reap c->btree_cache_freeable from the tail in bch_mca_scan() colyli
2020-01-23 17:01 ` [PATCH 17/17] bcache: reap from tail of c->btree_cache " colyli
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