Return-Path: Received: from mail-it0-f68.google.com ([209.85.214.68]:33461 "EHLO mail-it0-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932469AbcIAOuq (ORCPT ); Thu, 1 Sep 2016 10:50:46 -0400 Received: by mail-it0-f68.google.com with SMTP id g185so3653361ith.0 for ; Thu, 01 Sep 2016 07:50:46 -0700 (PDT) Subject: [PATCH] svcauth_gss: Revert 64c59a3726f2 ("Remove unnecessary allocation") From: Chuck Lever To: bfields@fieldses.org Cc: linux-nfs@vger.kernel.org Date: Thu, 01 Sep 2016 10:50:38 -0400 Message-ID: <20160901144839.6035.63068.stgit@klimt.1015granger.net> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Sender: linux-nfs-owner@vger.kernel.org List-ID: On occasion I see this on my server: kernel: kernel BUG at /home/cel/src/linux/linux-2.6/mm/slub.c:3851! kernel: invalid opcode: 0000 [#1] SMP kernel: Modules linked in: cts rpcsec_gss_krb5 sb_edac edac_core x86_pkg_temp_thermal intel_powerclamp coretemp kvm_intel kvm irqbypass crct10dif_pclmul crc32_pclmul ghash_clmulni_intel aesni_intel lrw gf128mul glue_helper ablk_helper cryptd btrfs xor iTCO_wdt iTCO_vendor_support raid6_pq pcspkr i2c_i801 i2c_smbus lpc_ich mfd_core mei_me sg mei shpchp wmi ioatdma ipmi_si ipmi_msghandler acpi_pad acpi_power_meter rpcrdma ib_ipoib rdma_ucm ib_ucm ib_uverbs ib_umad rdma_cm ib_cm iw_cm nfsd nfs_acl lockd grace auth_rpcgss sunrpc ip_tables xfs libcrc32c mlx4_ib mlx4_en ib_core sr_mod cdrom sd_mod ast drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops ttm drm crc32c_intel igb mlx4_core ahci libahci libata ptp pps_core dca i2c_algo_bit i2c_core dm_mirror dm_region_hash dm_log dm_mod kernel: CPU: 7 PID: 145 Comm: kworker/7:2 Not tainted 4.8.0-rc4-00006-g9d06b0b #15 kernel: Hardware name: Supermicro Super Server/X10SRL-F, BIOS 1.0c 09/09/2015 kernel: Workqueue: events do_cache_clean [sunrpc] kernel: task: ffff8808541d8000 task.stack: ffff880854344000 kernel: RIP: 0010:[] [] kfree+0x155/0x180 kernel: RSP: 0018:ffff880854347d70 EFLAGS: 00010246 kernel: RAX: ffffea0020fe7660 RBX: ffff88083f9db064 RCX: 146ff0f9d5ec5600 kernel: RDX: 000077ff80000000 RSI: ffff880853f01500 RDI: ffff88083f9db064 kernel: RBP: ffff880854347d88 R08: ffff8808594ee000 R09: ffff88087fdd8780 kernel: R10: 0000000000000000 R11: ffffea0020fe76c0 R12: ffff880853f01500 kernel: R13: ffffffffa013cf76 R14: ffffffffa013cff0 R15: ffffffffa04253a0 kernel: FS: 0000000000000000(0000) GS:ffff88087fdc0000(0000) knlGS:0000000000000000 kernel: CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 kernel: CR2: 00007fed60b020c3 CR3: 0000000001c06000 CR4: 00000000001406e0 kernel: Stack: kernel: ffff8808589f2f00 ffff880853f01500 0000000000000001 ffff880854347da0 kernel: ffffffffa013cf76 ffff8808589f2f00 ffff880854347db8 ffffffffa013d006 kernel: ffff8808589f2f20 ffff880854347e00 ffffffffa0406f60 0000000057c7044f kernel: Call Trace: kernel: [] rsc_free+0x16/0x90 [auth_rpcgss] kernel: [] rsc_put+0x16/0x30 [auth_rpcgss] kernel: [] cache_clean+0x2e0/0x300 [sunrpc] kernel: [] do_cache_clean+0xe/0x70 [sunrpc] kernel: [] process_one_work+0x1ff/0x3b0 kernel: [] worker_thread+0x2bc/0x4a0 kernel: [] ? rescuer_thread+0x3a0/0x3a0 kernel: [] kthread+0xe4/0xf0 kernel: [] ret_from_fork+0x1f/0x40 kernel: [] ? kthread_stop+0x110/0x110 kernel: Code: f7 ff ff eb 3b 65 8b 05 da 30 e2 7e 89 c0 48 0f a3 05 a0 38 b8 00 0f 92 c0 84 c0 0f 85 d1 fe ff ff 0f 1f 44 00 00 e9 f5 fe ff ff <0f> 0b 49 8b 03 31 f6 f6 c4 40 0f 85 62 ff ff ff e9 61 ff ff ff kernel: RIP [] kfree+0x155/0x180 kernel: RSP kernel: ---[ end trace 3fdec044969def26 ]--- It seems to be most common after a server reboot where a client has been using a Kerberos mount, and reconnects to continue its workload. Signed-off-by: Chuck Lever --- Hi Bruce- I've hit this off-and-on oops since 64c59a3726f2 was merged. Reverting it seems to make the problem go away. I haven't dug into why. Thoughts? net/sunrpc/auth_gss/svcauth_gss.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/net/sunrpc/auth_gss/svcauth_gss.c b/net/sunrpc/auth_gss/svcauth_gss.c index 1d28181..d858202 100644 --- a/net/sunrpc/auth_gss/svcauth_gss.c +++ b/net/sunrpc/auth_gss/svcauth_gss.c @@ -569,9 +569,10 @@ gss_svc_searchbyctx(struct cache_detail *cd, struct xdr_netobj *handle) struct rsc *found; memset(&rsci, 0, sizeof(rsci)); - rsci.handle.data = handle->data; - rsci.handle.len = handle->len; + if (dup_to_netobj(&rsci.handle, handle->data, handle->len)) + return NULL; found = rsc_lookup(cd, &rsci); + rsc_free(&rsci); if (!found) return NULL; if (cache_check(cd, &found->h, NULL))