From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
stable@vger.kernel.org, Xiyu Yang <xiyuyang19@fudan.edu.cn>,
Xin Tan <tanxin.ctf@gmail.com>, David Sterba <dsterba@suse.com>
Subject: [PATCH 4.9 05/18] btrfs: fix block group leak when removing fails
Date: Mon, 4 May 2020 19:57:15 +0200 [thread overview]
Message-ID: <20200504165443.251593903@linuxfoundation.org> (raw)
In-Reply-To: <20200504165442.028485341@linuxfoundation.org>
From: Xiyu Yang <xiyuyang19@fudan.edu.cn>
commit f6033c5e333238f299c3ae03fac8cc1365b23b77 upstream.
btrfs_remove_block_group() invokes btrfs_lookup_block_group(), which
returns a local reference of the block group that contains the given
bytenr to "block_group" with increased refcount.
When btrfs_remove_block_group() returns, "block_group" becomes invalid,
so the refcount should be decreased to keep refcount balanced.
The reference counting issue happens in several exception handling paths
of btrfs_remove_block_group(). When those error scenarios occur such as
btrfs_alloc_path() returns NULL, the function forgets to decrease its
refcnt increased by btrfs_lookup_block_group() and will cause a refcnt
leak.
Fix this issue by jumping to "out_put_group" label and calling
btrfs_put_block_group() when those error scenarios occur.
CC: stable@vger.kernel.org # 4.4+
Signed-off-by: Xiyu Yang <xiyuyang19@fudan.edu.cn>
Signed-off-by: Xin Tan <tanxin.ctf@gmail.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
fs/btrfs/extent-tree.c | 16 ++++++++++------
1 file changed, 10 insertions(+), 6 deletions(-)
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -10645,7 +10645,7 @@ int btrfs_remove_block_group(struct btrf
path = btrfs_alloc_path();
if (!path) {
ret = -ENOMEM;
- goto out;
+ goto out_put_group;
}
/*
@@ -10684,7 +10684,7 @@ int btrfs_remove_block_group(struct btrf
ret = btrfs_orphan_add(trans, inode);
if (ret) {
btrfs_add_delayed_iput(inode);
- goto out;
+ goto out_put_group;
}
clear_nlink(inode);
/* One for the block groups ref */
@@ -10707,13 +10707,13 @@ int btrfs_remove_block_group(struct btrf
ret = btrfs_search_slot(trans, tree_root, &key, path, -1, 1);
if (ret < 0)
- goto out;
+ goto out_put_group;
if (ret > 0)
btrfs_release_path(path);
if (ret == 0) {
ret = btrfs_del_item(trans, tree_root, path);
if (ret)
- goto out;
+ goto out_put_group;
btrfs_release_path(path);
}
@@ -10871,9 +10871,9 @@ int btrfs_remove_block_group(struct btrf
ret = remove_block_group_free_space(trans, root->fs_info, block_group);
if (ret)
- goto out;
+ goto out_put_group;
- btrfs_put_block_group(block_group);
+ /* Once for the block groups rbtree */
btrfs_put_block_group(block_group);
ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
@@ -10883,6 +10883,10 @@ int btrfs_remove_block_group(struct btrf
goto out;
ret = btrfs_del_item(trans, root, path);
+
+out_put_group:
+ /* Once for the lookup reference */
+ btrfs_put_block_group(block_group);
out:
btrfs_free_path(path);
return ret;
next prev parent reply other threads:[~2020-05-04 18:15 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-04 17:57 [PATCH 4.9 00/18] 4.9.222-rc1 review Greg Kroah-Hartman
2020-05-04 17:57 ` [PATCH 4.9 01/18] ext4: fix special inode number checks in __ext4_iget() Greg Kroah-Hartman
2020-05-04 17:57 ` [PATCH 4.9 02/18] drm/edid: Fix off-by-one in DispID DTD pixel clock Greg Kroah-Hartman
2020-05-04 17:57 ` [PATCH 4.9 03/18] drm/qxl: qxl_release leak in qxl_draw_dirty_fb() Greg Kroah-Hartman
2020-05-04 17:57 ` [PATCH 4.9 04/18] drm/qxl: qxl_release leak in qxl_hw_surface_alloc() Greg Kroah-Hartman
2020-05-04 17:57 ` Greg Kroah-Hartman [this message]
2020-05-04 17:57 ` [PATCH 4.9 06/18] ALSA: hda/hdmi: fix without unlocked before return Greg Kroah-Hartman
2020-05-04 17:57 ` [PATCH 4.9 07/18] ALSA: pcm: oss: Place the plugin buffer overflow checks correctly Greg Kroah-Hartman
2020-05-04 17:57 ` [PATCH 4.9 08/18] PM: ACPI: Output correct message on target power state Greg Kroah-Hartman
2020-05-04 17:57 ` [PATCH 4.9 09/18] PM: hibernate: Freeze kernel threads in software_resume() Greg Kroah-Hartman
2020-05-04 17:57 ` [PATCH 4.9 10/18] dm verity fec: fix hash block number in verity_fec_decode Greg Kroah-Hartman
2020-05-04 17:57 ` [PATCH 4.9 11/18] RDMA/mlx4: Initialize ib_spec on the stack Greg Kroah-Hartman
2020-05-04 17:57 ` [PATCH 4.9 12/18] vfio/type1: Fix VA->PA translation for PFNMAP VMAs in vaddr_get_pfn() Greg Kroah-Hartman
2020-05-04 17:57 ` [PATCH 4.9 13/18] iommu/amd: Fix legacy interrupt remapping for x2APIC-enabled system Greg Kroah-Hartman
2020-05-04 17:57 ` [PATCH 4.9 14/18] ALSA: opti9xx: shut up gcc-10 range warning Greg Kroah-Hartman
2020-05-04 17:57 ` [PATCH 4.9 15/18] nfs: Fix potential posix_acl refcnt leak in nfs3_set_acl Greg Kroah-Hartman
2020-05-04 17:57 ` [PATCH 4.9 16/18] dmaengine: dmatest: Fix iteration non-stop logic Greg Kroah-Hartman
2020-05-04 17:57 ` [PATCH 4.9 17/18] selinux: properly handle multiple messages in selinux_netlink_send() Greg Kroah-Hartman
2020-05-04 17:57 ` [PATCH 4.9 18/18] drm/qxl: qxl_release use after free Greg Kroah-Hartman
2020-05-05 8:37 ` [PATCH 4.9 00/18] 4.9.222-rc1 review Jon Hunter
2020-05-05 15:44 ` Naresh Kamboju
2020-05-05 15:47 ` Guenter Roeck
2020-05-05 15:56 ` shuah
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