* [Cluster-devel] [PATCH 1/1] gfs2: incorrect check for debugfs returns
@ 2015-03-24 2:36 Chengyu Song
2015-03-24 10:21 ` Steven Whitehouse
2015-03-30 14:16 ` Bob Peterson
0 siblings, 2 replies; 3+ messages in thread
From: Chengyu Song @ 2015-03-24 2:36 UTC (permalink / raw)
To: cluster-devel.redhat.com
debugfs_create_dir and debugfs_create_file may return -ENODEV when debugfs
is not configured, so the return value should be checked against ERROR_VALUE
as well, otherwise the later dereference of the dentry pointer would crash
the kernel.
Signed-off-by: Chengyu Song <csong84@gatech.edu>
---
fs/gfs2/glock.c | 47 ++++++++++++++++++++++++++++-------------------
1 file changed, 28 insertions(+), 19 deletions(-)
diff --git a/fs/gfs2/glock.c b/fs/gfs2/glock.c
index f42dffb..0fa8062 100644
--- a/fs/gfs2/glock.c
+++ b/fs/gfs2/glock.c
@@ -2047,34 +2047,41 @@ static const struct file_operations gfs2_sbstats_fops = {
int gfs2_create_debugfs_file(struct gfs2_sbd *sdp)
{
- sdp->debugfs_dir = debugfs_create_dir(sdp->sd_table_name, gfs2_root);
- if (!sdp->debugfs_dir)
- return -ENOMEM;
- sdp->debugfs_dentry_glocks = debugfs_create_file("glocks",
- S_IFREG | S_IRUGO,
- sdp->debugfs_dir, sdp,
- &gfs2_glocks_fops);
- if (!sdp->debugfs_dentry_glocks)
+ struct dentry *dent;
+
+ dent = debugfs_create_dir(sdp->sd_table_name, gfs2_root);
+ if (IS_ERR_OR_NULL(dent))
+ goto fail;
+ sdp->debugfs_dir = dent;
+
+ dent = debugfs_create_file("glocks",
+ S_IFREG | S_IRUGO,
+ sdp->debugfs_dir, sdp,
+ &gfs2_glocks_fops);
+ if (IS_ERR_OR_NULL(dent))
goto fail;
+ sdp->debugfs_dentry_glocks = dent;
- sdp->debugfs_dentry_glstats = debugfs_create_file("glstats",
- S_IFREG | S_IRUGO,
- sdp->debugfs_dir, sdp,
- &gfs2_glstats_fops);
- if (!sdp->debugfs_dentry_glstats)
+ dent = debugfs_create_file("glstats",
+ S_IFREG | S_IRUGO,
+ sdp->debugfs_dir, sdp,
+ &gfs2_glstats_fops);
+ if (IS_ERR_OR_NULL(dent))
goto fail;
+ sdp->debugfs_dentry_glstats = dent;
- sdp->debugfs_dentry_sbstats = debugfs_create_file("sbstats",
- S_IFREG | S_IRUGO,
- sdp->debugfs_dir, sdp,
- &gfs2_sbstats_fops);
- if (!sdp->debugfs_dentry_sbstats)
+ dent = debugfs_create_file("sbstats",
+ S_IFREG | S_IRUGO,
+ sdp->debugfs_dir, sdp,
+ &gfs2_sbstats_fops);
+ if (IS_ERR_OR_NULL(dent))
goto fail;
+ sdp->debugfs_dentry_sbstats = dent;
return 0;
fail:
gfs2_delete_debugfs_file(sdp);
- return -ENOMEM;
+ return dent ? PTR_ERR(dent) : -ENOMEM;
}
void gfs2_delete_debugfs_file(struct gfs2_sbd *sdp)
@@ -2100,6 +2107,8 @@ void gfs2_delete_debugfs_file(struct gfs2_sbd *sdp)
int gfs2_register_debugfs(void)
{
gfs2_root = debugfs_create_dir("gfs2", NULL);
+ if (IS_ERR(gfs2_root))
+ return PTR_ERR(gfs2_root);
return gfs2_root ? 0 : -ENOMEM;
}
--
2.1.0
^ permalink raw reply related [flat|nested] 3+ messages in thread* [Cluster-devel] [PATCH 1/1] gfs2: incorrect check for debugfs returns
2015-03-24 2:36 [Cluster-devel] [PATCH 1/1] gfs2: incorrect check for debugfs returns Chengyu Song
@ 2015-03-24 10:21 ` Steven Whitehouse
2015-03-30 14:16 ` Bob Peterson
1 sibling, 0 replies; 3+ messages in thread
From: Steven Whitehouse @ 2015-03-24 10:21 UTC (permalink / raw)
To: cluster-devel.redhat.com
Hi,
On 24/03/15 02:36, Chengyu Song wrote:
> debugfs_create_dir and debugfs_create_file may return -ENODEV when debugfs
> is not configured, so the return value should be checked against ERROR_VALUE
> as well, otherwise the later dereference of the dentry pointer would crash
> the kernel.
Looks reasonable to me:
Acked-by: Steven Whitehouse <swhiteho@redhat.com>
Steve.
> Signed-off-by: Chengyu Song <csong84@gatech.edu>
> ---
> fs/gfs2/glock.c | 47 ++++++++++++++++++++++++++++-------------------
> 1 file changed, 28 insertions(+), 19 deletions(-)
>
> diff --git a/fs/gfs2/glock.c b/fs/gfs2/glock.c
> index f42dffb..0fa8062 100644
> --- a/fs/gfs2/glock.c
> +++ b/fs/gfs2/glock.c
> @@ -2047,34 +2047,41 @@ static const struct file_operations gfs2_sbstats_fops = {
>
> int gfs2_create_debugfs_file(struct gfs2_sbd *sdp)
> {
> - sdp->debugfs_dir = debugfs_create_dir(sdp->sd_table_name, gfs2_root);
> - if (!sdp->debugfs_dir)
> - return -ENOMEM;
> - sdp->debugfs_dentry_glocks = debugfs_create_file("glocks",
> - S_IFREG | S_IRUGO,
> - sdp->debugfs_dir, sdp,
> - &gfs2_glocks_fops);
> - if (!sdp->debugfs_dentry_glocks)
> + struct dentry *dent;
> +
> + dent = debugfs_create_dir(sdp->sd_table_name, gfs2_root);
> + if (IS_ERR_OR_NULL(dent))
> + goto fail;
> + sdp->debugfs_dir = dent;
> +
> + dent = debugfs_create_file("glocks",
> + S_IFREG | S_IRUGO,
> + sdp->debugfs_dir, sdp,
> + &gfs2_glocks_fops);
> + if (IS_ERR_OR_NULL(dent))
> goto fail;
> + sdp->debugfs_dentry_glocks = dent;
>
> - sdp->debugfs_dentry_glstats = debugfs_create_file("glstats",
> - S_IFREG | S_IRUGO,
> - sdp->debugfs_dir, sdp,
> - &gfs2_glstats_fops);
> - if (!sdp->debugfs_dentry_glstats)
> + dent = debugfs_create_file("glstats",
> + S_IFREG | S_IRUGO,
> + sdp->debugfs_dir, sdp,
> + &gfs2_glstats_fops);
> + if (IS_ERR_OR_NULL(dent))
> goto fail;
> + sdp->debugfs_dentry_glstats = dent;
>
> - sdp->debugfs_dentry_sbstats = debugfs_create_file("sbstats",
> - S_IFREG | S_IRUGO,
> - sdp->debugfs_dir, sdp,
> - &gfs2_sbstats_fops);
> - if (!sdp->debugfs_dentry_sbstats)
> + dent = debugfs_create_file("sbstats",
> + S_IFREG | S_IRUGO,
> + sdp->debugfs_dir, sdp,
> + &gfs2_sbstats_fops);
> + if (IS_ERR_OR_NULL(dent))
> goto fail;
> + sdp->debugfs_dentry_sbstats = dent;
>
> return 0;
> fail:
> gfs2_delete_debugfs_file(sdp);
> - return -ENOMEM;
> + return dent ? PTR_ERR(dent) : -ENOMEM;
> }
>
> void gfs2_delete_debugfs_file(struct gfs2_sbd *sdp)
> @@ -2100,6 +2107,8 @@ void gfs2_delete_debugfs_file(struct gfs2_sbd *sdp)
> int gfs2_register_debugfs(void)
> {
> gfs2_root = debugfs_create_dir("gfs2", NULL);
> + if (IS_ERR(gfs2_root))
> + return PTR_ERR(gfs2_root);
> return gfs2_root ? 0 : -ENOMEM;
> }
>
^ permalink raw reply [flat|nested] 3+ messages in thread* [Cluster-devel] [PATCH 1/1] gfs2: incorrect check for debugfs returns
2015-03-24 2:36 [Cluster-devel] [PATCH 1/1] gfs2: incorrect check for debugfs returns Chengyu Song
2015-03-24 10:21 ` Steven Whitehouse
@ 2015-03-30 14:16 ` Bob Peterson
1 sibling, 0 replies; 3+ messages in thread
From: Bob Peterson @ 2015-03-30 14:16 UTC (permalink / raw)
To: cluster-devel.redhat.com
----- Original Message -----
> debugfs_create_dir and debugfs_create_file may return -ENODEV when debugfs
> is not configured, so the return value should be checked against ERROR_VALUE
> as well, otherwise the later dereference of the dentry pointer would crash
> the kernel.
>
> Signed-off-by: Chengyu Song <csong84@gatech.edu>
> ---
> fs/gfs2/glock.c | 47 ++++++++++++++++++++++++++++-------------------
> 1 file changed, 28 insertions(+), 19 deletions(-)
Hi,
I've now added this patch to the for-next branch of the linux-gfs2.git
tree. Thanks.
Regards,
Bob Peterson
Red Hat File Systems
^ permalink raw reply [flat|nested] 3+ messages in thread
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2015-03-24 2:36 [Cluster-devel] [PATCH 1/1] gfs2: incorrect check for debugfs returns Chengyu Song
2015-03-24 10:21 ` Steven Whitehouse
2015-03-30 14:16 ` Bob Peterson
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