On 11/24/2016 09:29 AM, Roi Dayan wrote:
Hi,I'm testing this patch with KASAN enabled and got into a new kernel crash I didn't hit before. [ 1860.725065] ================================================================== [ 1860.733893] BUG: KASAN: use-after-free in __netif_receive_skb_core+0x1ebe/0x29a0 at addr ffff880a68b04028 [ 1860.745415] Read of size 8 by task CPU 0/KVM/5334 [ 1860.751368] CPU: 8 PID: 5334 Comm: CPU 0/KVM Tainted: G O 4.9.0-rc3+ #18 [ 1860.760547] Hardware name: HP ProLiant DL380p Gen8, BIOS P70 07/01/2015 [ 1860.768036] Call Trace: [ 1860.771307] [<ffffffffa9b6dc42>] dump_stack+0x63/0x81 [ 1860.777167] [<ffffffffa95fb751>] kasan_object_err+0x21/0x70 [ 1860.783826] [<ffffffffa95fb9dd>] kasan_report_error+0x1ed/0x4e0 [ 1860.790640] [<ffffffffa9b9b841>] ? csum_partial+0x11/0x20 [ 1860.796871] [<ffffffffaa44a6b9>] ? csum_partial_ext+0x9/0x10 [ 1860.803571] [<ffffffffaa453155>] ? __skb_checksum+0x115/0x8d0 [ 1860.810370] [<ffffffffa95fbe81>] __asan_report_load8_noabort+0x61/0x70 [ 1860.818263] [<ffffffffaa49c3fe>] ? __netif_receive_skb_core+0x1ebe/0x29a0 [ 1860.826215] [<ffffffffaa49c3fe>] __netif_receive_skb_core+0x1ebe/0x29a0 [ 1860.833991] [<ffffffffaa49a540>] ? netdev_info+0x100/0x100 [ 1860.840529] [<ffffffffaa671792>] ? udp4_gro_receive+0x802/0x1090 [ 1860.847783] [<ffffffffa9bb9a08>] ? find_next_bit+0x18/0x20 [ 1860.854126] [<ffffffffaa49cf04>] __netif_receive_skb+0x24/0x150 [ 1860.861695] [<ffffffffaa49d0d1>] netif_receive_skb_internal+0xa1/0x1d0 [ 1860.869366] [<ffffffffaa49d030>] ? __netif_receive_skb+0x150/0x150 [ 1860.876464] [<ffffffffaa49f7e9>] ? dev_gro_receive+0x969/0x1660 [ 1860.883924] [<ffffffffaa4a0e1f>] napi_gro_receive+0x1df/0x300 [ 1860.890744] [<ffffffffc02e885d>] mlx5e_handle_rx_cqe_rep+0x83d/0xd30 [mlx5_core] checking with gdb (gdb) l *(__netif_receive_skb_core+0x1ebe) 0xffffffff8249c3fe is in __netif_receive_skb_core (net/core/dev.c:3937). 3932 *pt_prev = NULL; 3933 } 3934 3935 qdisc_skb_cb(skb)->pkt_len = skb->len; 3936 skb->tc_verd = SET_TC_AT(skb->tc_verd, AT_INGRESS); 3937 qdisc_bstats_cpu_update(cl->q, skb); 3938 3939 switch (tc_classify(skb, cl, &cl_res, false)) { 3940 case TC_ACT_OK: 3941 case TC_ACT_RECLASSIFY:
Can you elaborate some more on your test-case? Adding/dropping ingress qdisc with some classifier on it in a loop while traffic goes through? Thanks, Daniel
