When mb-xdp is set and return is XDP_PASS, packet is converted from
xdp_buff to sk_buff with xdp_update_skb_shared_info() in
bnxt_xdp_build_skb().
bnxt_xdp_build_skb() passes incorrect truesize argument to
xdp_update_skb_shared_info().
The truesize is calculated as BNXT_RX_PAGE_SIZE * sinfo->nr_frags but
the skb_shared_info was wiped by napi_build_skb() before.
So it stores skb_shared_info before bnxt_xdp_build_skb() and use it
instead of getting skb_shared_info from xdp_get_shared_info_from_buff().
Splat looks like:
------------[ cut here ]------------
WARNING: CPU: 2 PID: 0 at net/core/skbuff.c:6072 skb_try_coalesce+0x504/0x590
Modules linked in: xt_nat xt_tcpudp veth af_packet xt_conntrack nft_chain_nat
xt_MASQUERADE nf_conntrack_netlink xfrm_user xt_addrtype nft_coms
CPU: 2 UID: 0 PID: 0 Comm: swapper/2 Not tainted 6.14.0-rc2+ #3
RIP: 0010:skb_try_coalesce+0x504/0x590
Code: 4b fd ff ff 49 8b 34 24 40 80 e6 40 0f 84 3d fd ff ff 49 8b 74 24 48 40
f6 c6 01 0f 84 2e fd ff ff 48 8d 4e ff e9 25 fd ff ff <0f> 0b e99
RSP: 0018:ffffb62c4120caa8 EFLAGS: 00010287
RAX: 0000000000000003 RBX: ffffb62c4120cb14 RCX: 0000000000000ec0
RDX: 0000000000001000 RSI: ffffa06e5d7dc000 RDI: 0000000000000003
RBP: ffffa06e5d7ddec0 R08: ffffa06e6120a800 R09: ffffa06e7a119900
R10: 0000000000002310 R11: ffffa06e5d7dcec0 R12: ffffe4360575f740
R13: ffffe43600000000 R14: 0000000000000002 R15: 0000000000000002
FS: 0000000000000000(0000) GS:ffffa0755f700000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f147b76b0f8 CR3: 00000001615d4000 CR4: 00000000007506f0
PKRU: 55555554
Call Trace:
<IRQ>
? __warn+0x84/0x130
? skb_try_coalesce+0x504/0x590
? report_bug+0x18a/0x1a0
? handle_bug+0x53/0x90
? exc_invalid_op+0x14/0x70
? asm_exc_invalid_op+0x16/0x20
? skb_try_coalesce+0x504/0x590
inet_frag_reasm_finish+0x11f/0x2e0
ip_defrag+0x37a/0x900
ip_local_deliver+0x51/0x120
ip_sublist_rcv_finish+0x64/0x70
ip_sublist_rcv+0x179/0x210
ip_list_rcv+0xf9/0x130
How to reproduce:
<Node A>
ip link set $interface1 xdp obj xdp_pass.o
ip link set $interface1 mtu 9000 up
ip a a 10.0.0.1/24 dev $interface1
<Node B>
ip link set $interfac2 mtu 9000 up
ip a a 10.0.0.2/24 dev $interface2
ping 10.0.0.1 -s 65000
Following ping.py patch adds xdp-mb-pass case. so ping.py is going to be
able to reproduce this issue.
Fixes: 1dc4c557bfed ("bnxt: adding bnxt_xdp_build_skb to build skb from
multibuffer xdp_buff")
Signed-off-by: Taehee Yoo <ap420...@gmail.com>
---
v2:
- Do not use num_frags in the bnxt_xdp_build_skb().
drivers/net/ethernet/broadcom/bnxt/bnxt.c | 30 +++++++++----------
drivers/net/ethernet/broadcom/bnxt/bnxt_xdp.c | 7 ++---
drivers/net/ethernet/broadcom/bnxt/bnxt_xdp.h | 4 +--
3 files changed, 20 insertions(+), 21 deletions(-)
diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.c
b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
index 7b8b5b39c7bb..13c9be49216a 100644
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt.c
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
@@ -2040,6 +2040,7 @@ static int bnxt_rx_pkt(struct bnxt *bp, struct
bnxt_cp_ring_info *cpr,
u16 cons, prod, cp_cons = RING_CMP(tmp_raw_cons);
struct bnxt_sw_rx_bd *rx_buf;
unsigned int len;
+ struct skb_shared_info sinfo = {0};
u8 *data_ptr, agg_bufs, cmp_type;
bool xdp_active = false;
dma_addr_t dma_addr;
@@ -2166,13 +2167,12 @@ static int bnxt_rx_pkt(struct bnxt *bp, struct
bnxt_cp_ring_info *cpr,
goto oom_next_rx;
}
xdp_active = true;
- }
-
- if (xdp_active) {
if (bnxt_rx_xdp(bp, rxr, cons, &xdp, data, &data_ptr, &len,
event)) {
rc = 1;
goto next_rx;
}
+ memcpy(&sinfo, xdp_get_shared_info_from_buff(&xdp),
+ sizeof(struct skb_shared_info));
}
if (len <= bp->rx_copybreak) {
@@ -2204,18 +2204,18 @@ static int bnxt_rx_pkt(struct bnxt *bp, struct
bnxt_cp_ring_info *cpr,
goto oom_next_rx;
}
- if (agg_bufs) {
- if (!xdp_active) {
- skb = bnxt_rx_agg_pages_skb(bp, cpr, skb, cp_cons,
agg_bufs, false);
- if (!skb)
- goto oom_next_rx;
- } else {
- skb = bnxt_xdp_build_skb(bp, skb, agg_bufs,
rxr->page_pool, &xdp, rxcmp1);
- if (!skb) {
- /* we should be able to free the old skb here */
- bnxt_xdp_buff_frags_free(rxr, &xdp);
- goto oom_next_rx;
- }
+ if (!xdp_active && agg_bufs) {
+ skb = bnxt_rx_agg_pages_skb(bp, cpr, skb, cp_cons, agg_bufs,
+ false);
+ if (!skb)
+ goto oom_next_rx;
+ } else if (xdp_active && xdp_buff_has_frags(&xdp)) {
+ skb = bnxt_xdp_build_skb(bp, skb, &sinfo, rxr->page_pool, &xdp,
+ rxcmp1);
+ if (!skb) {
+ /* we should be able to free the old skb here */
+ bnxt_xdp_buff_frags_free(rxr, &xdp);
+ goto oom_next_rx;
}
}
diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt_xdp.c
b/drivers/net/ethernet/broadcom/bnxt/bnxt_xdp.c
index e6c64e4bd66c..77860848e4f9 100644
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt_xdp.c
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt_xdp.c
@@ -459,12 +459,11 @@ int bnxt_xdp(struct net_device *dev, struct netdev_bpf
*xdp)
}
struct sk_buff *
-bnxt_xdp_build_skb(struct bnxt *bp, struct sk_buff *skb, u8 num_frags,
+bnxt_xdp_build_skb(struct bnxt *bp, struct sk_buff *skb,
+ struct skb_shared_info *sinfo,
struct page_pool *pool, struct xdp_buff *xdp,
struct rx_cmp_ext *rxcmp1)
{
- struct skb_shared_info *sinfo = xdp_get_shared_info_from_buff(xdp);
-
if (!skb)
return NULL;
skb_checksum_none_assert(skb);
@@ -474,7 +473,7 @@ bnxt_xdp_build_skb(struct bnxt *bp, struct sk_buff *skb, u8
num_frags,
skb->csum_level = RX_CMP_ENCAP(rxcmp1);
}
}
- xdp_update_skb_shared_info(skb, num_frags,
+ xdp_update_skb_shared_info(skb, sinfo->nr_frags,
sinfo->xdp_frags_size,
BNXT_RX_PAGE_SIZE * sinfo->nr_frags,
xdp_buff_is_frag_pfmemalloc(xdp));
diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt_xdp.h
b/drivers/net/ethernet/broadcom/bnxt/bnxt_xdp.h
index 0122782400b8..c1974bffafe5 100644
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt_xdp.h
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt_xdp.h
@@ -32,7 +32,7 @@ void bnxt_xdp_buff_init(struct bnxt *bp, struct
bnxt_rx_ring_info *rxr,
void bnxt_xdp_buff_frags_free(struct bnxt_rx_ring_info *rxr,
struct xdp_buff *xdp);
struct sk_buff *bnxt_xdp_build_skb(struct bnxt *bp, struct sk_buff *skb,
- u8 num_frags, struct page_pool *pool,
- struct xdp_buff *xdp,
+ struct skb_shared_info *sinfo,
+ struct page_pool *pool, struct xdp_buff *xdp,
struct rx_cmp_ext *rxcmp1);
#endif
--
2.34.1
