fs/orangefs/orangefs-debugfs.c | 11 +++++------ 1 file changed, 5 insertions(+), 6 deletions(-)
Replace kzalloc() followed by copy_from_user() with memdup_user_nul() to
simplify and improve orangefs_debug_write(). Allocate only 'count' bytes
instead of the maximum size ORANGEFS_MAX_DEBUG_STRING_LEN, and set 'buf'
to NULL to ensure kfree(buf) still works.
No functional changes intended.
Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
---
fs/orangefs/orangefs-debugfs.c | 11 +++++------
1 file changed, 5 insertions(+), 6 deletions(-)
diff --git a/fs/orangefs/orangefs-debugfs.c b/fs/orangefs/orangefs-debugfs.c
index 1c375fb65018..79267b3419f2 100644
--- a/fs/orangefs/orangefs-debugfs.c
+++ b/fs/orangefs/orangefs-debugfs.c
@@ -440,14 +440,13 @@ static ssize_t orangefs_debug_write(struct file *file,
count = ORANGEFS_MAX_DEBUG_STRING_LEN;
}
- buf = kzalloc(ORANGEFS_MAX_DEBUG_STRING_LEN, GFP_KERNEL);
- if (!buf)
- goto out;
-
- if (copy_from_user(buf, ubuf, count - 1)) {
+ buf = memdup_user_nul(ubuf, count - 1);
+ if (IS_ERR(buf)) {
gossip_debug(GOSSIP_DEBUGFS_DEBUG,
- "%s: copy_from_user failed!\n",
+ "%s: memdup_user_nul failed!\n",
__func__);
+ rc = PTR_ERR(buf);
+ buf = NULL;
goto out;
}
--
2.51.0
Thanks, that looks better in several ways. I ran it through xfstests, and have added it to my linux-next tree... -Mike On Thu, Sep 18, 2025 at 11:08 AM Thorsten Blum <thorsten.blum@linux.dev> wrote: > > Replace kzalloc() followed by copy_from_user() with memdup_user_nul() to > simplify and improve orangefs_debug_write(). Allocate only 'count' bytes > instead of the maximum size ORANGEFS_MAX_DEBUG_STRING_LEN, and set 'buf' > to NULL to ensure kfree(buf) still works. > > No functional changes intended. > > Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev> > --- > fs/orangefs/orangefs-debugfs.c | 11 +++++------ > 1 file changed, 5 insertions(+), 6 deletions(-) > > diff --git a/fs/orangefs/orangefs-debugfs.c b/fs/orangefs/orangefs-debugfs.c > index 1c375fb65018..79267b3419f2 100644 > --- a/fs/orangefs/orangefs-debugfs.c > +++ b/fs/orangefs/orangefs-debugfs.c > @@ -440,14 +440,13 @@ static ssize_t orangefs_debug_write(struct file *file, > count = ORANGEFS_MAX_DEBUG_STRING_LEN; > } > > - buf = kzalloc(ORANGEFS_MAX_DEBUG_STRING_LEN, GFP_KERNEL); > - if (!buf) > - goto out; > - > - if (copy_from_user(buf, ubuf, count - 1)) { > + buf = memdup_user_nul(ubuf, count - 1); > + if (IS_ERR(buf)) { > gossip_debug(GOSSIP_DEBUGFS_DEBUG, > - "%s: copy_from_user failed!\n", > + "%s: memdup_user_nul failed!\n", > __func__); > + rc = PTR_ERR(buf); > + buf = NULL; > goto out; > } > > -- > 2.51.0 >
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