Received-SPF: pass (google.com: domain of linux-wireless-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Sender: Larry Finger <larry.finger@gmail.com>
Message-ID: <cdd2ebad-cae6-70e2-87a6-84f75f227150@lwfinger.net>
Date:   Tue, 16 May 2023 22:07:05 -0500
MIME-Version: 1.0
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101
 Thunderbird/102.11.0
Content-Language: en-US
To:     Kalle Valo <kvalo@kernel.org>
Cc:     linux-wireless <linux-wireless@vger.kernel.org>,
        Pkshih <pkshih@realtek.com>
From:   Larry Finger <Larry.Finger@lwfinger.net>
Subject: Bug in commit b2cbac9b9b28
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 7bit
Precedence: bulk

Kalle,

Commit b2cbac9b9b28 ("net: Remove low_thresh in ip defrag") results in warnings 
like the following:

[11278.308851] ------------[ cut here ]------------
[11278.308854] sysctl net/ipv4/ipfrag_low_thresh: data points to kernel global 
data: ipfrag_low_thresh_unused
[11278.308896] WARNING: CPU: 2 PID: 2603 at net/sysctl_net.c:155 
register_net_sysctl+0xab/0x150
[11278.308902] Modules linked in: vboxnetadp(OE) vboxnetflt(OE) vboxdrv(OE) 
rfcomm(E) ccm(E) rpcsec_gss_krb5(E) auth_rpcgss(E) nfsv4(E) dns_resolver(E) 
nfs(E) lockd(E) grace(E) sunrpc(E) fscache(E) netfs(E) af_packet(E) cmac(E) 
algif_hash(E) algif_skcipher(E) af_alg(E) qrtr(E) bnep(E) btusb(E) btrtl(E) 
btbcm(E) btintel(E) btmtk(E) bluetooth(E) ecdh_generic(E) binfmt_misc(E) 
nls_iso8859_1(E) nls_cp437(E) vfat(E) iwlmvm(E) rtw89_8851be(E) fat(E) 
rtw89_8851b(E) rtw89_pci(E) intel_rapl_msr(E) rtw89_core(E) intel_rapl_common(E) 
x86_pkg_temp_thermal(E) intel_powerclamp(E) coretemp(E) snd_hda_codec_realtek(E) 
snd_hda_codec_generic(E) mac80211(E) ledtrig_audio(E) kvm_intel(E) iTCO_wdt(E) 
spi_intel_platform(E) intel_pmc_bxt(E) spi_intel(E) iTCO_vendor_support(E) 
snd_hda_codec_hdmi(E) iwlwifi(E) mei_pxp(E) mei_hdcp(E) snd_hda_intel(E) kvm(E) 
snd_intel_dspcfg(E) libarc4(E) snd_hda_codec(E) irqbypass(E) snd_hwdep(E) 
pcspkr(E) snd_hda_core(E) cfg80211(E) wmi_bmof(E) snd_pcm(E) lpc_ich(E) 
mei_me(E) snd_timer(E) snd(E) toshiba_acpi(E)
[11278.308958]  thermal(E) mei(E) e1000e(E) tiny_power_button(E) soundcore(E) 
sparse_keymap(E) toshiba_bluetooth(E) industrialio(E) battery(E) tpm_infineon(E) 
ac(E) button(E) joydev(E) fuse(E) configfs(E) dmi_sysfs(E) ext4(E) mbcache(E) 
jbd2(E) crct10dif_pclmul(E) crc32_pclmul(E) crc32c_intel(E) polyval_clmulni(E) 
polyval_generic(E) ghash_clmulni_intel(E) sha512_ssse3(E) i915(E) 
i2c_algo_bit(E) drm_buddy(E) rtsx_pci_sdmmc(E) mmc_core(E) drm_display_helper(E) 
drm_kms_helper(E) syscopyarea(E) sysfillrect(E) sysimgblt(E) aesni_intel(E) 
crypto_simd(E) ehci_pci(E) sr_mod(E) cec(E) xhci_pci(E) xhci_pci_renesas(E) 
ttm(E) cryptd(E) xhci_hcd(E) cdrom(E) ehci_hcd(E) rtsx_pci(E) drm(E) usbcore(E) 
video(E) wmi(E) serio_raw(E) sg(E) dm_multipath(E) dm_mod(E) scsi_dh_rdac(E) 
scsi_dh_emc(E) scsi_dh_alua(E) msr(E)
[11278.309005] Unloaded tainted modules: acpi_cpufreq(E):1 ie31200_edac(E):1
[11278.309009] CPU: 2 PID: 2603 Comm: chrome Tainted: G        W  OE 
6.4.0-rc1-wireless_next-g082489a6b7fd #12 5a2b2d499aad74f4cae3c5aa9f2f676e9892c87c
[11278.309013] Hardware name: TOSHIBA TECRA A50-A/TECRA A50-A, BIOS Version 4.50 
   09/29/2014
[11278.309014] RIP: 0010:register_net_sysctl+0xab/0x150
[11278.309018] Code: c0 b1 72 b9 48 81 fd 00 00 00 b3 73 b0 48 c7 c1 5a 40 ea b0 
48 8b 13 4c 8b 43 08 4c 89 ee 48 c7 c7 08 ba fa b0 e8 a5 5f 62 ff <0f> 0b 66 81 
63 14 6d ff 48 8b 53 40 48 83 c3 40 48 85 d2 75 8b 5b
[11278.309019] RSP: 0018:ffffb93ac8937c30 EFLAGS: 00010282
[11278.309022] RAX: 0000000000000000 RBX: ffff9953b8ee7e40 RCX: 0000000000000027
[11278.309024] RDX: ffff9953e32a24c8 RSI: 0000000000000001 RDI: ffff9953e32a24c0
[11278.309025] RBP: ffffffffb2d0f2e8 R08: 0000000000000000 R09: ffffb93ac8937ad8
[11278.309026] R10: 0000000000000003 R11: ffff9953ef546fa8 R12: ffff9951fe649400
[11278.309028] R13: ffffffffb0fa0c46 R14: ffff9953b8ee7e00 R15: 0000000070000000
[11278.309029] FS:  00007fe6c4030040(0000) GS:ffff9953e3280000(0000) 
knlGS:0000000000000000
[11278.309031] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[11278.309032] CR2: 00007fff7a7b0000 CR3: 00000002c4acc001 CR4: 00000000001706e0
[11278.309034] Call Trace:
[11278.309036]  <TASK>
[11278.309038]  ipv4_frags_init_net+0xdd/0x170
[11278.309041]  ops_init+0x37/0x120
[11278.309045]  setup_net+0x12a/0x290
[11278.309047]  copy_net_ns+0x106/0x260
[11278.309050]  create_new_namespaces+0x113/0x2e0
[11278.309053]  copy_namespaces+0x8d/0x100
[11278.309056]  copy_process+0xee5/0x1c20
[11278.309060]  kernel_clone+0x98/0x3a0
[11278.309063]  __do_sys_clone+0x66/0x90
[11278.309066]  do_syscall_64+0x56/0x80
[11278.309069]  ? exc_page_fault+0x6d/0x150
[11278.309073]  entry_SYSCALL_64_after_hwframe+0x46/0xb0
[11278.309078] RIP: 0033:0x7fe6c5272a66
[11278.309080] Code: 85 ff 74 3e 48 83 e6 f0 74 38 48 89 4e f8 48 83 ee 10 48 89 
3e 48 89 d7 4c 89 c2 4d 89 c8 4c 8b 54 24 08 b8 38 00 00 00 0f 05 <48> 85 c0 7c 
13 74 01 c3 31 ed 58 5f ff d0 48 89 c7 b8 3c 00 00 00
[11278.309082] RSP: 002b:00007fff7a7af158 EFLAGS: 00000206 ORIG_RAX: 
0000000000000038
[11278.309085] RAX: ffffffffffffffda RBX: 00007fff7a7b31b0 RCX: 00007fe6c5272a66
[11278.309086] RDX: 0000000000000000 RSI: 00007fff7a7b3160 RDI: 0000000070000011
[11278.309088] RBP: 00007fff7a7b31a0 R08: 0000000000000000 R09: 0000000000000000
[11278.309089] R10: 0000000000000000 R11: 0000000000000206 R12: 0000000070000011
[11278.309091] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
[11278.309093]  </TASK>
[11278.309094] ---[ end trace 0000000000000000 ]---

I ran across this because I needed to run the most recent copy of wireless-next 
to test a new driver in the rtw89 family. After a scare about the new driver 
causing this problem, I tested wireless-next tip and found this problem on a 
machine with no wifi. I bisected the problem and found the bad commit.

This problem has been reported [1] to the author of the bad commit. I think the 
bad patch should be reverted; however, my main reason for this report is to 
alert other users of wireless-next to the problem.

Larry

[1] 
https://lore.kernel.org/lkml/168413702530.26935.9409301901790238640.git-patchwork-notify@kernel.org/T/#mb006308491b7d83517e02c916b6f3de0e33697c7