Hi- This WARN popped up on an NFS server I was testing via TCP (IP over IB on a CX-5 VPI NIC) There did not seem to be any other ill effects, but since this appears to indicate an unexpected memory overwrite, I am reporting it. memcpy: detected field-spanning write (size 56) of single field "eseg->inline_hdr.start" at drivers/infiniband/hw/mlx5/wr.c:81 (size 2) WARNING: CPU: 2 PID: 1217 at drivers/infiniband/hw/mlx5/wr.c:81 mlx5_ib_post_send+0x59d/0x867 [mlx5_ib] Modules linked in: rpcsec_gss_krb5 nfsv4 dns_resolver nfs rfkill rpcrdma rdma_ucm ib_srpt ib_isert ib_umad iscsi_target_mod ib_iser ib_ipoib li> CPU: 2 PID: 1217 Comm: nfsd Not tainted 6.4.0-rc4-00025-gf900df712a57 #1 Hardware name: Supermicro Super Server/X10SRL-F, BIOS 3.3 10/28/2020 RIP: 0010:mlx5_ib_post_send+0x59d/0x867 [mlx5_ib] Code: 32 b9 02 00 00 00 48 c7 c2 9e e8 a2 c0 48 89 c6 48 c7 c7 e3 e8 a2 c0 4c 89 8d 70 ff ff ff c6 05 b8 f5 00 00 01 e8 19 3a 6f e5 <0f> 0b 4c 8b 8d 70 ff ff ff 48 8b 7d 90 48 8b b5 78 ff ff ff 4c 89 RSP: 0018:ffffa7444d88b6f8 EFLAGS: 00010086 RAX: 0000000000000087 RBX: ffff92f446dd8000 RCX: 0000000000000027 RDX: 0000000000000027 RSI: ffffa7444d88b5d0 RDI: ffff93037fd1c6c0 RBP: ffffa7444d88b788 R08: 0000000000000000 R09: ffffa744418e0020 R10: 0000000000000001 R11: 0000000000aaaaaa R12: ffff92f44a488748 R13: 0000000000000038 R14: ffffa7444d88b7c0 R15: 0000000000000003 FS: 0000000000000000(0000) GS:ffff93037fd00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005555556bf640 CR3: 000000010b968005 CR4: 00000000001706e0 Call Trace: <TASK> ? show_regs+0x5d/0x64 ? mlx5_ib_post_send+0x59d/0x867 [mlx5_ib] ? __warn+0xbf/0x13c ? report_bug+0xfc/0x16b ? mlx5_ib_post_send+0x59d/0x867 [mlx5_ib] ? handle_bug+0x45/0x74 ? exc_invalid_op+0x18/0x6b ? asm_exc_invalid_op+0x1b/0x20 ? mlx5_ib_post_send+0x59d/0x867 [mlx5_ib] ? mlx5_ib_post_send+0x59d/0x867 [mlx5_ib] mlx5_ib_post_send_nodrain+0xb/0x11 [mlx5_ib] ipoib_send+0x424/0x4e0 [ib_ipoib] ipoib_start_xmit+0x4c3/0x57d [ib_ipoib] ? netif_skb_features+0x1a1/0x1f2 netdev_start_xmit+0x1f/0x41 dev_hard_start_xmit+0xb7/0x14c sch_direct_xmit+0xd5/0x219 __dev_queue_xmit+0x59a/0x7b8 ? xfs_vn_update_time+0x156/0x167 [xfs] ? push_pseudo_header+0x17/0x2b [ib_ipoib] ? ipoib_hard_header+0x37/0x46 [ib_ipoib] neigh_connected_output+0x9b/0xb7 ip_finish_output2+0x39e/0x3f5 __ip_finish_output+0x125/0x139 ip_finish_output+0x98/0xb8 ip_output+0x5b/0x91 dst_output+0x2c/0x39 ip_local_out+0x34/0x3a .... -- Chuck Lever
