Linux-bcachefs Archive mirror
 help / color / mirror / Atom feed
From: Su Yue <glass.su@suse.com>
To: linux-bcachefs@vger.kernel.org
Cc: l@damenly.org, Su Yue <glass.su@suse.com>
Subject: [PATCH] bcachefs: fix kmemleak in __bch2_read_super error handling path
Date: Fri,  9 Feb 2024 21:41:31 +0800	[thread overview]
Message-ID: <20240209134131.50597-1-l@damenly.org> (raw)

From: Su Yue <glass.su@suse.com>

During xfstest tests, there are some kmemleak reports e.g. generic/051 with
if USE_KMEMLEAK=yes:

====================================================================
EXPERIMENTAL kmemleak reported some memory leaks!  Due to the way kmemleak
works, the leak might be from an earlier test, or something totally unrelated.
unreferenced object 0xffff9ef905aaf778 (size 8):
  comm "mount.bcachefs", pid 169844, jiffies 4295281209 (age 87.040s)
  hex dump (first 8 bytes):
    a5 cc cc cc cc cc cc cc                          ........
  backtrace:
    [<ffffffff87fd9a43>] __kmem_cache_alloc_node+0x1f3/0x2c0
    [<ffffffff87f49b66>] kmalloc_trace+0x26/0xb0
    [<ffffffffc0a3fefe>] __bch2_read_super+0xfe/0x4e0 [bcachefs]
    [<ffffffffc0a3ad22>] bch2_fs_open+0x262/0x1710 [bcachefs]
    [<ffffffffc09c9e24>] bch2_mount+0x4c4/0x640 [bcachefs]
    [<ffffffff88080c90>] legacy_get_tree+0x30/0x60
    [<ffffffff8802c748>] vfs_get_tree+0x28/0xf0
    [<ffffffff88061fe5>] path_mount+0x475/0xb60
    [<ffffffff880627e5>] __x64_sys_mount+0x105/0x140
    [<ffffffff88932642>] do_syscall_64+0x42/0xf0
    [<ffffffff88a000e6>] entry_SYSCALL_64_after_hwframe+0x6e/0x76
unreferenced object 0xffff9ef96cdc4fc0 (size 32):
  comm "mount.bcachefs", pid 169844, jiffies 4295281209 (age 87.040s)
  hex dump (first 32 bytes):
    2f 64 65 76 2f 6d 61 70 70 65 72 2f 74 65 73 74  /dev/mapper/test
    2d 31 00 cc cc cc cc cc cc cc cc cc cc cc cc cc  -1..............
  backtrace:
    [<ffffffff87fd9a43>] __kmem_cache_alloc_node+0x1f3/0x2c0
    [<ffffffff87f4a081>] __kmalloc_node_track_caller+0x51/0x150
    [<ffffffff87f3adc2>] kstrdup+0x32/0x60
    [<ffffffffc0a3ff1a>] __bch2_read_super+0x11a/0x4e0 [bcachefs]
    [<ffffffffc0a3ad22>] bch2_fs_open+0x262/0x1710 [bcachefs]
    [<ffffffffc09c9e24>] bch2_mount+0x4c4/0x640 [bcachefs]
    [<ffffffff88080c90>] legacy_get_tree+0x30/0x60
    [<ffffffff8802c748>] vfs_get_tree+0x28/0xf0
    [<ffffffff88061fe5>] path_mount+0x475/0xb60
    [<ffffffff880627e5>] __x64_sys_mount+0x105/0x140
    [<ffffffff88932642>] do_syscall_64+0x42/0xf0
    [<ffffffff88a000e6>] entry_SYSCALL_64_after_hwframe+0x6e/0x76
====================================================================

The leak happens if bdev_open_by_path() failed to open a block device
then it goes label 'out' directly without call of bch2_free_super().

Fix it by going to label 'err' instead of 'out' if bdev_open_by_path()
fails.

Signed-off-by: Su Yue <glass.su@suse.com>
---
 fs/bcachefs/super-io.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/bcachefs/super-io.c b/fs/bcachefs/super-io.c
index d60c7d27a047..36988add581f 100644
--- a/fs/bcachefs/super-io.c
+++ b/fs/bcachefs/super-io.c
@@ -717,7 +717,7 @@ static int __bch2_read_super(const char *path, struct bch_opts *opts,
 
 	if (IS_ERR(sb->bdev_handle)) {
 		ret = PTR_ERR(sb->bdev_handle);
-		goto out;
+		goto err;
 	}
 	sb->bdev = sb->bdev_handle->bdev;
 
-- 
2.43.0


                 reply	other threads:[~2024-02-09 13:41 UTC|newest]

Thread overview: [no followups] expand[flat|nested]  mbox.gz  Atom feed

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20240209134131.50597-1-l@damenly.org \
    --to=glass.su@suse.com \
    --cc=l@damenly.org \
    --cc=linux-bcachefs@vger.kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).