diff options
| author | Sebastian Andrzej Siewior <bigeasy@linutronix.de> | 2024-07-04 16:48:15 +0200 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2024-07-05 16:59:37 -0700 |
| commit | fecef4cd42c689a200bdd39e6fffa71475904bc1 (patch) | |
| tree | 77e6bcb7cb0d8cb5b656646e071fc92d1b13bf7a | |
| parent | 3b2aef99221d395ce37efa426d7b50e7dcd621d6 (diff) | |
tun: Assign missing bpf_net_context.
During the introduction of struct bpf_net_context handling for
XDP-redirect, the tun driver has been missed.
Jakub also pointed out that there is another call chain to
do_xdp_generic() originating from netif_receive_skb() and drivers may
use it outside from the NAPI context.
Set the bpf_net_context before invoking BPF XDP program within the TUN
driver. Set the bpf_net_context also in do_xdp_generic() if a xdp
program is available.
Reported-by: syzbot+0b5c75599f1d872bea6f@syzkaller.appspotmail.com
Reported-by: syzbot+5ae46b237278e2369cac@syzkaller.appspotmail.com
Reported-by: syzbot+c1e04a422bbc0f0f2921@syzkaller.appspotmail.com
Fixes: 401cb7dae8130 ("net: Reference bpf_redirect_info via task_struct on PREEMPT_RT.")
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Link: https://patch.msgid.link/20240704144815.j8xQda5r@linutronix.de
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
| -rw-r--r-- | drivers/net/tun.c | 7 | ||||
| -rw-r--r-- | net/core/dev.c | 5 |
2 files changed, 12 insertions, 0 deletions
diff --git a/drivers/net/tun.c b/drivers/net/tun.c index 9254bca2813d..9b24861464bc 100644 --- a/drivers/net/tun.c +++ b/drivers/net/tun.c @@ -1661,6 +1661,7 @@ static struct sk_buff *tun_build_skb(struct tun_struct *tun, int len, int *skb_xdp) { struct page_frag *alloc_frag = ¤t->task_frag; + struct bpf_net_context __bpf_net_ctx, *bpf_net_ctx; struct bpf_prog *xdp_prog; int buflen = SKB_DATA_ALIGN(sizeof(struct skb_shared_info)); char *buf; @@ -1700,6 +1701,7 @@ static struct sk_buff *tun_build_skb(struct tun_struct *tun, local_bh_disable(); rcu_read_lock(); + bpf_net_ctx = bpf_net_ctx_set(&__bpf_net_ctx); xdp_prog = rcu_dereference(tun->xdp_prog); if (xdp_prog) { struct xdp_buff xdp; @@ -1728,12 +1730,14 @@ static struct sk_buff *tun_build_skb(struct tun_struct *tun, pad = xdp.data - xdp.data_hard_start; len = xdp.data_end - xdp.data; } + bpf_net_ctx_clear(bpf_net_ctx); rcu_read_unlock(); local_bh_enable(); return __tun_build_skb(tfile, alloc_frag, buf, buflen, len, pad); out: + bpf_net_ctx_clear(bpf_net_ctx); rcu_read_unlock(); local_bh_enable(); return NULL; @@ -2566,6 +2570,7 @@ static int tun_sendmsg(struct socket *sock, struct msghdr *m, size_t total_len) if (m->msg_controllen == sizeof(struct tun_msg_ctl) && ctl && ctl->type == TUN_MSG_PTR) { + struct bpf_net_context __bpf_net_ctx, *bpf_net_ctx; struct tun_page tpage; int n = ctl->num; int flush = 0, queued = 0; @@ -2574,6 +2579,7 @@ static int tun_sendmsg(struct socket *sock, struct msghdr *m, size_t total_len) local_bh_disable(); rcu_read_lock(); + bpf_net_ctx = bpf_net_ctx_set(&__bpf_net_ctx); for (i = 0; i < n; i++) { xdp = &((struct xdp_buff *)ctl->ptr)[i]; @@ -2588,6 +2594,7 @@ static int tun_sendmsg(struct socket *sock, struct msghdr *m, size_t total_len) if (tfile->napi_enabled && queued > 0) napi_schedule(&tfile->napi); + bpf_net_ctx_clear(bpf_net_ctx); rcu_read_unlock(); local_bh_enable(); diff --git a/net/core/dev.c b/net/core/dev.c index 385c4091aa77..73e5af6943c3 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -5126,11 +5126,14 @@ static DEFINE_STATIC_KEY_FALSE(generic_xdp_needed_key); int do_xdp_generic(struct bpf_prog *xdp_prog, struct sk_buff **pskb) { + struct bpf_net_context __bpf_net_ctx, *bpf_net_ctx; + if (xdp_prog) { struct xdp_buff xdp; u32 act; int err; + bpf_net_ctx = bpf_net_ctx_set(&__bpf_net_ctx); act = netif_receive_generic_xdp(pskb, &xdp, xdp_prog); if (act != XDP_PASS) { switch (act) { @@ -5144,11 +5147,13 @@ int do_xdp_generic(struct bpf_prog *xdp_prog, struct sk_buff **pskb) generic_xdp_tx(*pskb, xdp_prog); break; } + bpf_net_ctx_clear(bpf_net_ctx); return XDP_DROP; } } return XDP_PASS; out_redir: + bpf_net_ctx_clear(bpf_net_ctx); kfree_skb_reason(*pskb, SKB_DROP_REASON_XDP); return XDP_DROP; } |