From: Shaomin Chen iptfs_clone_state() clones the IPTFS mode data with kmemdup(). This copies runtime objects which must not be shared with the original SA, including the embedded sk_buff_head, hrtimers, spinlock, and in-flight reassembly/reorder state. If xfrm_state_migrate() fails after clone_state() but before the later init_state() call has reinitialized those fields, the cloned state can be destroyed by xfrm_state_gc_task() with list and timer state copied from the original SA. With queued packets this lets the clone splice and free skbs owned by the original IPTFS queue, leading to use-after-free and double-free reports in iptfs_destroy_state() and skb release paths. Reinitialize the clone's runtime state before publishing it through x->mode_data. Because clone_state() now publishes a destroyable mode_data object before init_state(), take the mode callback module reference there. Avoid taking it again from __iptfs_init_state() for the same object. Fixes: 0e4fbf013fa5 ("xfrm: iptfs: add user packet (tunnel ingress) handling") Cc: stable@vger.kernel.org Signed-off-by: Shaomin Chen Signed-off-by: Steffen Klassert --- net/xfrm/xfrm_iptfs.c | 28 +++++++++++++++++++++++----- 1 file changed, 23 insertions(+), 5 deletions(-) diff --git a/net/xfrm/xfrm_iptfs.c b/net/xfrm/xfrm_iptfs.c index 97bc979e55ba..6c6bbc040517 100644 --- a/net/xfrm/xfrm_iptfs.c +++ b/net/xfrm/xfrm_iptfs.c @@ -2650,7 +2650,8 @@ static void __iptfs_init_state(struct xfrm_state *x, x->props.enc_hdr_len = sizeof(struct ip_iptfs_hdr); /* Always keep a module reference when x->mode_data is set */ - __module_get(x->mode_cbs->owner); + if (x->mode_data != xtfs) + __module_get(x->mode_cbs->owner); x->mode_data = xtfs; xtfs->x = x; @@ -2658,22 +2659,39 @@ static void __iptfs_init_state(struct xfrm_state *x, static int iptfs_clone_state(struct xfrm_state *x, struct xfrm_state *orig) { + struct skb_wseq *w_saved = NULL; struct xfrm_iptfs_data *xtfs; xtfs = kmemdup(orig->mode_data, sizeof(*xtfs), GFP_KERNEL); if (!xtfs) return -ENOMEM; - xtfs->ra_newskb = NULL; if (xtfs->cfg.reorder_win_size) { - xtfs->w_saved = kzalloc_objs(*xtfs->w_saved, - xtfs->cfg.reorder_win_size); - if (!xtfs->w_saved) { + w_saved = kzalloc_objs(*w_saved, xtfs->cfg.reorder_win_size); + if (!w_saved) { kfree_sensitive(xtfs); return -ENOMEM; } } + xtfs->w_saved = w_saved; + + __skb_queue_head_init(&xtfs->queue); + xtfs->queue_size = 0; + hrtimer_setup(&xtfs->iptfs_timer, iptfs_delay_timer, CLOCK_MONOTONIC, + IPTFS_HRTIMER_MODE); + + spin_lock_init(&xtfs->drop_lock); + hrtimer_setup(&xtfs->drop_timer, iptfs_drop_timer, CLOCK_MONOTONIC, + IPTFS_HRTIMER_MODE); + xtfs->w_seq_set = false; + xtfs->w_wantseq = 0; + xtfs->w_savedlen = 0; + xtfs->ra_newskb = NULL; + xtfs->ra_wantseq = 0; + xtfs->ra_runtlen = 0; + + __module_get(x->mode_cbs->owner); x->mode_data = xtfs; xtfs->x = x; -- 2.43.0