On Tue, 05 Oct 2010, Miklos Szeredi wrote: > From: Miklos Szeredi <mszeredi@xxxxxxx> > > If clone_mnt() happens while mnt_make_readonly() is running, the > cloned mount might have MNT_WRITE_HOLD flag set, which results in > mnt_want_write() spinning forever on this mount. > > Needs CAP_SYS_ADMIN to trigger deliberately and unlikely to happen > accidentally. But if it does happen it can hang the machine. > > Signed-off-by: Miklos Szeredi <mszeredi@xxxxxxx> Forgot to add CC: stable@xxxxxxxxxx > --- > fs/namespace.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > Index: linux-2.6/fs/namespace.c > =================================================================== > --- linux-2.6.orig/fs/namespace.c 2010-10-01 21:54:17.000000000 +0200 > +++ linux-2.6/fs/namespace.c 2010-10-01 21:54:30.000000000 +0200 > @@ -595,7 +595,7 @@ static struct vfsmount *clone_mnt(struct > goto out_free; > } > > - mnt->mnt_flags = old->mnt_flags; > + mnt->mnt_flags = old->mnt_flags & ~MNT_WRITE_HOLD; > atomic_inc(&sb->s_active); > mnt->mnt_sb = sb; > mnt->mnt_root = dget(root); > > -- > -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
