Messages in this thread | | | From | "Yan, Zheng" <> | Date | Fri, 14 Oct 2016 10:47:51 +0800 | Subject | Re: [PATCH] ceph: Fix uninitialized dentry pointer in ceph_real_mount() |
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On Thu, Oct 13, 2016 at 11:15 PM, Geert Uytterhoeven <geert@linux-m68k.org> wrote: > fs/ceph/super.c: In function ‘ceph_real_mount’: > fs/ceph/super.c:818: warning: ‘root’ may be used uninitialized in this function > > If s_root is already valid, dentry pointer root is never initialized, > and returned by ceph_real_mount(). This will cause a crash later when > the caller dereferences the pointer. > > Fix this by initializing root early. > > Fixes: ce2728aaa82bbeba ("ceph: avoid accessing / when mounting a subpath") > Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> > --- > Compile-tested only. > --- > fs/ceph/super.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/fs/ceph/super.c b/fs/ceph/super.c > index a29ffce981879d5f..794c5fd0e0cf5e45 100644 > --- a/fs/ceph/super.c > +++ b/fs/ceph/super.c > @@ -821,7 +821,8 @@ static struct dentry *ceph_real_mount(struct ceph_fs_client *fsc) > dout("mount start %p\n", fsc); > mutex_lock(&fsc->client->mount_mutex); > > - if (!fsc->sb->s_root) { > + root = fsc->sb->s_root; > + if (!root) { > const char *path; > err = __ceph_open_session(fsc->client, started); > if (err < 0)
For sb->s_root is not NULL case, we also need to increase sb->s_root's reference count. I applied this patch and fixed it.
Regards Yan, Zheng
> -- > 1.9.1 >
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