On 03/17/18 19:41, Carlos Carvalho wrote: > I've put 4.14.27 this morning in this machine and in about 2h it started > showing null dereferences identical to the following one. There were several > of > them, with about 1/2h of interval. Strangely it continued to work and I saw no > other anomalies. I've just reverted to 4.14.26. > > It only happened in this machine, which has a net traffic of several Gb/s and > thousands of simultaneous connections. > > Mar 17 13:29:21 sagres kernel: : BUG: unable to handle kernel NULL pointer > dereference at 0000000000000038 > Mar 17 13:29:21 sagres kernel: : IP: tcp_push+0x4e/0xe7 > Mar 17 13:29:21 sagres kernel: : PGD 0 P4D 0 > Mar 17 13:29:21 sagres kernel: : Oops: 0002 [#1] SMP PTI > Mar 17 13:29:21 sagres kernel: : CPU: 55 PID: 2658 Comm: apache2 Not tainted > 4.14.27 #4 > Mar 17 13:29:21 sagres kernel: : task: ffff89791cf7e600 task.stack: > ffffabdd91db8000 > Mar 17 13:29:21 sagres kernel: : RIP: 0010:tcp_push+0x4e/0xe7 > Mar 17 13:29:21 sagres kernel: : RSP: 0018:ffffabdd91dbbc10 EFLAGS: 00010246 > Mar 17 13:29:21 sagres kernel: : RAX: 0000000000000000 RBX: 00000000000004c4 > RCX: 0000000000000001 > Mar 17 13:29:21 sagres kernel: : RDX: 0000000000000001 RSI: 0000000000000040 > RDI: ffff89968330a100 > Mar 17 13:29:21 sagres kernel: : RBP: ffff89968330a250 R08: 0000000000007be8 > R09: ffffe77cbfc4ab00 > Mar 17 13:29:21 sagres kernel: : R10: ffff89968330a250 R11: 0000000000000000 > R12: ffff8987aab3bb80 > Mar 17 13:29:21 sagres kernel: : R13: ffff89968330a100 R14: ffff89791cf7e930 > R15: 00000000ffffffe0 > Mar 17 13:29:21 sagres kernel: : FS: 00007f0bd67d4700(0000) > GS:ffff89993f4c0000(0000) knlGS:0000000000000000 > Mar 17 13:29:21 sagres kernel: : CS: 0010 DS: 0000 ES: 0000 CR0: > 0000000080050033 > Mar 17 13:29:21 sagres kernel: : CR2: 0000000000000038 CR3: 0000003ff4842006 > CR4: 00000000003606e0 > Mar 17 13:29:21 sagres kernel: : DR0: 0000000000000000 DR1: 0000000000000000 > DR2: 0000000000000000 > Mar 17 13:29:21 sagres kernel: : DR3: 0000000000000000 DR6: 00000000fffe0ff0 > DR7: 0000000000000400 > Mar 17 13:29:21 sagres kernel: : Call Trace: > Mar 17 13:29:21 sagres kernel: : tcp_sendmsg_locked+0xac6/0xc1e > Mar 17 13:29:21 sagres kernel: : tcp_sendmsg+0x23/0x35 > Mar 17 13:29:21 sagres kernel: : sock_sendmsg+0x11/0x1b > Mar 17 13:29:21 sagres kernel: : sock_write_iter+0x71/0x87 > Mar 17 13:29:21 sagres kernel: : do_iter_readv_writev+0xf0/0x111 > Mar 17 13:29:21 sagres kernel: : do_iter_write+0x84/0xf0 > Mar 17 13:29:21 sagres kernel: : vfs_writev+0xad/0xfb > Mar 17 13:29:21 sagres kernel: : ? do_writev+0x56/0x92 > Mar 17 13:29:21 sagres kernel: : do_writev+0x56/0x92 > Mar 17 13:29:21 sagres kernel: : do_syscall_64+0x181/0x210 > Mar 17 13:29:21 sagres kernel: : entry_SYSCALL_64_after_hwframe+0x3d/0xa2 > Mar 17 13:29:21 sagres kernel: : RIP: 0033:0x7f13f1264017 > Mar 17 13:29:21 sagres kernel: : RSP: 002b:00007f0bd67d2810 EFLAGS: 00000293 > ORIG_RAX: 0000000000000014 > Mar 17 13:29:21 sagres kernel: : RAX: ffffffffffffffda RBX: 0000000000000079 > RCX: 00007f13f1264017 > Mar 17 13:29:21 sagres kernel: : RDX: 000000000000000a RSI: 00007f0bd67d2970 > RDI: 0000000000000079 > Mar 17 13:29:21 sagres kernel: : RBP: 00007f0bd67d2970 R08: 0000000000000000 > R09: 00007f13680762c8 > Mar 17 13:29:21 sagres kernel: : R10: 0000556029c85dd4 R11: 0000000000000293 > R12: 000000000000000a > Mar 17 13:29:21 sagres kernel: : R13: 00007f0bd67d2970 R14: 00007f0bd67d28d0 > R15: 0000556029ea1440 > Mar 17 13:29:21 sagres kernel: : Code: d0 75 02 31 c0 41 89 f3 41 81 e3 00 80 > 00 00 74 1a 44 8b 8f 58 05 00 00 41 d1 e9 44 2b 8f 5c 06 00 00 44 03 8f 64 06 > 00 00 79 10 <80> 48 38 08 8b 8f 5c 06 00 00 89 8f 64 06 00 00 40 80 e6 01 74 > Mar 17 13:29:21 sagres kernel: : RIP: tcp_push+0x4e/0xe7 RSP: ffffabdd91dbbc10 > Mar 17 13:29:21 sagres kernel: : CR2: 0000000000000038 > Mar 17 13:29:21 sagres kernel: : ---[ end trace f9a8f71d250d2782 ]--- >
Fixed by: https://www.spinics.net/lists/netdev/msg489445.html -h
