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> --- 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
