Re: [PATCH] hfsplus: fix uninit-value in copy_name

[Edward Adam Davis <eadavis@qq.com>]

On Thu, 4 Jul 2024 15:36:37 +0200, Dmitry Vyukov wrote:
> > [syzbot reported]
> > BUG: KMSAN: uninit-value in sized_strscpy+0xc4/0x160
> >  sized_strscpy+0xc4/0x160
> >  copy_name+0x2af/0x320 fs/hfsplus/xattr.c:411
> >  hfsplus_listxattr+0x11e9/0x1a50 fs/hfsplus/xattr.c:750
> >  vfs_listxattr fs/xattr.c:493 [inline]
> >  listxattr+0x1f3/0x6b0 fs/xattr.c:840
> >  path_listxattr fs/xattr.c:864 [inline]
> >  __do_sys_listxattr fs/xattr.c:876 [inline]
> >  __se_sys_listxattr fs/xattr.c:873 [inline]
> >  __x64_sys_listxattr+0x16b/0x2f0 fs/xattr.c:873
> >  x64_sys_call+0x2ba0/0x3b50 arch/x86/include/generated/asm/syscalls_64.h:195
> >  do_syscall_x64 arch/x86/entry/common.c:52 [inline]
> >  do_syscall_64+0xcf/0x1e0 arch/x86/entry/common.c:83
> >  entry_SYSCALL_64_after_hwframe+0x77/0x7f
> >
> > Uninit was created at:
> >  slab_post_alloc_hook mm/slub.c:3877 [inline]
> >  slab_alloc_node mm/slub.c:3918 [inline]
> >  kmalloc_trace+0x57b/0xbe0 mm/slub.c:4065
> >  kmalloc include/linux/slab.h:628 [inline]
> >  hfsplus_listxattr+0x4cc/0x1a50 fs/hfsplus/xattr.c:699
> >  vfs_listxattr fs/xattr.c:493 [inline]
> >  listxattr+0x1f3/0x6b0 fs/xattr.c:840
> >  path_listxattr fs/xattr.c:864 [inline]
> >  __do_sys_listxattr fs/xattr.c:876 [inline]
> >  __se_sys_listxattr fs/xattr.c:873 [inline]
> >  __x64_sys_listxattr+0x16b/0x2f0 fs/xattr.c:873
> >  x64_sys_call+0x2ba0/0x3b50 arch/x86/include/generated/asm/syscalls_64.h:195
> >  do_syscall_x64 arch/x86/entry/common.c:52 [inline]
> >  do_syscall_64+0xcf/0x1e0 arch/x86/entry/common.c:83
> >  entry_SYSCALL_64_after_hwframe+0x77/0x7f
> > [Fix]
> > When allocating memory to strbuf, initialize memory to 0.
> >
> > Reported-and-tested-by: syzbot+efde959319469ff8d4d7@syzkaller.appspotmail.com
> > Signed-off-by: Edward Adam Davis <eadavis@qq.com>
> > ---
> >  fs/hfsplus/xattr.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/fs/hfsplus/xattr.c b/fs/hfsplus/xattr.c
> > index 9c9ff6b8c6f7..858029b1c173 100644
> > --- a/fs/hfsplus/xattr.c
> > +++ b/fs/hfsplus/xattr.c
> > @@ -698,7 +698,7 @@ ssize_t hfsplus_listxattr(struct dentry *dentry, char *buffer, size_t size)
> >                 return err;
> >         }
> >
> > -       strbuf = kmalloc(NLS_MAX_CHARSET_SIZE * HFSPLUS_ATTR_MAX_STRLEN +
> > +       strbuf = kzalloc(NLS_MAX_CHARSET_SIZE * HFSPLUS_ATTR_MAX_STRLEN +
> >                         XATTR_MAC_OSX_PREFIX_LEN + 1, GFP_KERNEL);
> >         if (!strbuf) {
> >                 res = -ENOMEM;
> 
> Hi Edward,
> 
> Was this ever merged anywhere? I still don't see it upstream.
Yes, me too.

--
Edward