Messages in this thread | | | Subject | Re: [PATCH] ubifs: Free memory for tmpfile name | From | Zhihao Cheng <> | Date | Thu, 30 Mar 2023 10:25:59 +0800 |
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Hi Mårten, > When opening a ubifs tmpfile on an encrypted directory, function > fscrypt_setup_filename allocates memory for the name that is to be > stored in the directory entry, but after the name has been copied to the > directory entry inode, the memory is not freed. > > When running kmemleak on it we see that it is registered as a leak. The > report below is triggered by a simple program 'tmpfile' just opening a > tmpfile: > > unreferenced object 0xffff88810178f380 (size 32): > comm "tmpfile", pid 509, jiffies 4294934744 (age 1524.742s) > backtrace: > __kmem_cache_alloc_node > __kmalloc > fscrypt_setup_filename > ubifs_tmpfile > vfs_tmpfile > path_openat > > Free this memory after it has been copied to the inode. > > Signed-off-by: Mårten Lindahl <marten.lindahl@axis.com> > --- > fs/ubifs/dir.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/fs/ubifs/dir.c b/fs/ubifs/dir.c > index 0f29cf201136..089ca6910124 100644 > --- a/fs/ubifs/dir.c > +++ b/fs/ubifs/dir.c > @@ -491,6 +491,7 @@ static int ubifs_tmpfile(struct user_namespace *mnt_userns, struct inode *dir, > goto out_cancel; > unlock_2_inodes(dir, inode); > > + fscrypt_free_filename(&nm); > ubifs_release_budget(c, &req); > > return finish_open_simple(file, 0);
Looks good, just one small nit. I'd prefer to add fscrypt_free_filename() after ubifs_release_budget() just like ubifs_create/link does, so that ubifs can get unused budget earlier.
After looking through the code, I found another place create_whiteout has the same problem(Imported in 278d9a243635f26c05("ubifs: Rename whiteout atomically") by me). Would you mind fixing this point just by removing unused 'nm' in create_whiteout()?
> > --- > base-commit: c9c3395d5e3dcc6daee66c6908354d47bf98cb0c > change-id: 20230329-memleak-fix-87a01daf469e > > Best regards, >
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