After updating to Fedora 42 kernel 6.16.3-200.fc42.x86_64, the system triggers a kernel BUG at mm/slub.c:546 during Wi-Fi initialization (iwlwifi). The crash happens shortly after boot, I am able to use wifi for sometime before it happens. Booting into an older kernel (6.14 / 6.15) avoids the issue. Hardware: Lenovo ThinkPad T430 (Model 2349UTY) BIOS: G1ET93WW (2.53), 03/08/2013 CPU: Intel (Sandy/Ivy Bridge) Wireless: Intel WiFi (handled by iwlwifi) Here is the crash.log Sep 01 23:59:12 fedora kernel: kernel BUG at mm/slub.c:546! Sep 01 23:59:12 fedora kernel: Oops: invalid opcode: 0000 [#1] SMP PTI Sep 01 23:59:12 fedora kernel: CPU: 0 UID: 0 PID: 11 Comm: kworker/0:1 Tainted: G W 6.16.3-200.fc42.x86_64 #1 PREEMPT(lazy) Sep 01 23:59:12 fedora kernel: Tainted: [W]=WARN Sep 01 23:59:12 fedora kernel: Hardware name: LENOVO 2349UTY/2349UTY, BIOS G1ET93WW (2.53 ) 03/08/2013 Sep 01 23:59:12 fedora kernel: Workqueue: events iwl_trans_reprobe_wk [iwlwifi] Sep 01 23:59:12 fedora kernel: RIP: 0010:__slab_free+0x111/0x2a0 Sep 01 23:59:12 fedora kernel: Code: 85 9e 00 00 00 4d 85 ff 0f 84 62 ff ff ff 48 8b 74 24 08 4c 89 ff e8 9e 27 e0 00 4c 8b 73 20 4c 3b 74 24 20 0f 85 55 ff ff ff <0f> 0b 66 90 45 31 ff 4d 85 f6 74 ad 48 8b 03 48 89 0c 24 48 c1 e8 Sep 01 23:59:12 fedora kernel: RSP: 0000:ffffcec100097c60 EFLAGS: 00010246 Sep 01 23:59:12 fedora kernel: RAX: 0000000000000000 RBX: fffff51c44258000 RCX: 0000000000000000 Sep 01 23:59:12 fedora kernel: RDX: ffff8de549600980 RSI: ffff8de549600980 RDI: ffffcec100097cd0 Sep 01 23:59:12 fedora kernel: RBP: ffffcec100097d00 R08: 0000000000000001 R09: ffffffffc0f97a04 Sep 01 23:59:12 fedora kernel: R10: ffff8de549600980 R11: fffff51c44258000 R12: ffff8de541ebbe00 Sep 01 23:59:12 fedora kernel: R13: ffff8de549600980 R14: ffff8de549600980 R15: ffff8de587e34608 Sep 01 23:59:12 fedora kernel: FS: 0000000000000000(0000) GS:ffff8de6b9e5f000(0000) knlGS:0000000000000000 Sep 01 23:59:12 fedora kernel: CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 Sep 01 23:59:12 fedora kernel: CR2: 00007fd4152444c0 CR3: 000000010985c006 CR4: 00000000001726f0 Sep 01 23:59:12 fedora kernel: Call Trace: Sep 01 23:59:12 fedora kernel: <TASK> Sep 01 23:59:12 fedora kernel: kfree+0x334/0x3b0 Sep 01 23:59:12 fedora kernel: ? __synchronize_hardirq+0x7f/0xc0 Sep 01 23:59:12 fedora kernel: iwl_pcie_txq_free+0x124/0x170 [iwlwifi] Sep 01 23:59:12 fedora kernel: iwl_pcie_tx_free+0x65/0xf0 [iwlwifi] Sep 01 23:59:12 fedora kernel: iwl_trans_pcie_free+0x1d5/0x260 [iwlwifi] Sep 01 23:59:12 fedora kernel: pci_device_remove+0x4a/0xc0 Sep 01 23:59:12 fedora kernel: device_release_driver_internal+0x19e/0x200 Sep 01 23:59:12 fedora kernel: device_reprobe+0x1d/0x90 Sep 01 23:59:12 fedora kernel: iwl_trans_reprobe_wk+0x1b/0x50 [iwlwifi] Sep 01 23:59:12 fedora kernel: process_one_work+0x192/0x350 Sep 01 23:59:12 fedora kernel: worker_thread+0x25a/0x3a0 Sep 01 23:59:12 fedora kernel: ? __pfx_worker_thread+0x10/0x10 Sep 01 23:59:12 fedora kernel: kthread+0xfc/0x240 Sep 01 23:59:12 fedora kernel: ? __pfx_kthread+0x10/0x10 Sep 01 23:59:12 fedora kernel: ? __pfx_kthread+0x10/0x10 Sep 01 23:59:12 fedora kernel: ret_from_fork+0x152/0x180 Sep 01 23:59:12 fedora kernel: ? __pfx_kthread+0x10/0x10 Sep 01 23:59:12 fedora kernel: ret_from_fork_asm+0x1a/0x30 Sep 01 23:59:12 fedora kernel: </TASK> Sep 01 23:59:12 fedora kernel: Modules linked in: uinput rfcomm snd_seq_dummy snd_hrtimer nf_conntrack_netbios_ns nf_conntrack_broadcast nft_fib_inet nft_fib_ipv4 nft_fib_ipv6 nft_fib nft_reject_inet nf_reject_ipv4 nf_reject_ipv6 nft_reject nft_ct nft_chain_nat nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 nf_tables qrtr bnep intel_rapl_msr intel_rapl_common snd_hda_codec_hdmi snd_hda_codec_realtek x86_pkg_temp_thermal snd_hda_codec_generic intel_powerclamp snd_hda_scodec_component coretemp snd_hda_intel iwldvm snd_intel_dspcfg kvm_intel snd_intel_sdw_acpi mac80211 snd_hda_codec kvm libarc4 btusb uvcvideo btrtl iwlwifi snd_hda_core btintel btbcm irqbypass snd_hwdep uvc videobuf2_vmalloc videobuf2_memops videobuf2_v4l2 snd_ctl_led videobuf2_common thinkpad_acpi btmtk videodev snd_seq iTCO_wdt snd_seq_device sparse_keymap snd_pcm intel_pmc_bxt cfg80211 platform_profile rapl iTCO_vendor_support snd_timer mc bluetooth mei_wdt at24 snd mei_hdcp intel_cstate think_lmi mei_pxp i2c_i801 cdc_acm pcspkr rfkill i2c_smbus mei_me Sep 01 23:59:12 fedora kernel: firmware_attributes_class soundcore wmi_bmof intel_uncore joydev lpc_ich mei pktcdvd loop zram lz4hc_compress lz4_compress i915 i2c_algo_bit sdhci_pci drm_buddy sdhci_uhs2 cdc_mbim ttm polyval_clmulni cdc_ncm drm_display_helper sdhci ghash_clmulni_intel cdc_ether sha512_ssse3 usbnet sha1_ssse3 cqhci e1000e mii cdc_wdm mmc_core cec video wmi serio_raw sunrpc iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi i2c_dev fuse nfnetlink Sep 01 23:59:12 fedora kernel: ---[ end trace 0000000000000000 ]---
I'm running Fedora 42 on a Thinkpad T420, and I'm getting this same error with kernel 6.16.3-200.fc42.x86_64 and 6.16.4-200.fc42.x86_64. The problem doesn't happen when I use kernel 6.15.10-200.fc42.x86_64. Once it happened after I logged in to Gnome. At other times, it mostly occurred after the system woke up from sleep and tried to reconnect to the wifi network, or sometime after it reconnected to the wifi network. The problem reporting tool, abrt, did detect/catch the issue once. According to it, the problematic package is kernel-core-6.16.4-200.fc42. The Report button is disabled for this System Failure. It does provide a URL - https://retrace.fedoraproject.org/faf/reports/1306123/. # System Details Report --- ## Report details - **Date generated:** 2025-09-05 20:57:41 ## Hardware Information: - **Hardware Model:** Lenovo ThinkPad T420 - **Memory:** 12.0 GiB - **Processor:** Intel® Core™ i5-2520M × 4 - **Graphics:** Intel® HD Graphics 3000 (SNB GT2) - **Disk Capacity:** 500.1 GB ## Software Information: - **Firmware Version:** 83ET82WW (1.52 ) - **OS Name:** Fedora Linux 42 (Workstation Edition) - **OS Build:** (null) - **OS Type:** 64-bit - **GNOME Version:** 48 - **Windowing System:** Wayland - **Kernel Version:** Linux 6.15.10-200.fc42.x86_64 Partial output of the command lspci -kv 03:00.0 Network controller: Intel Corporation Centrino Ultimate-N 6300 (rev 35) Subsystem: Intel Corporation Centrino Ultimate-N 6300 3x3 AGN Flags: bus master, fast devsel, latency 0, IRQ 27 Memory at f1400000 (64-bit, non-prefetchable) [size=8K] Capabilities: <access denied> Kernel driver in use: iwlwifi Kernel modules: iwlwifi I'm attaching the output of command 'journalctl --no-hostname -b'
Created attachment 2105769 [details] Ouput of command journalctl --no-hostname -b -3
Updated to kernel 6.16.5-200.fc42.x86_64 and the issue is still reproducible. The difference being that a new call trace is present along with the original call trace. Output of command 'journalctl --no-hostname -b' is attached.
Created attachment 2106189 [details] log from kernel version 6.15.10-200.fc42.x86_64
The attachment description above is incorrect. The log is from kernel 6.16.5-200.fc42.x86_64 and not 6.15.10-200.fc42.x86_64.
I'm unable to reproduce this issue with kernel 6.16.10. The issue persists up until 6.16.9. With 6.16.10, wifi connects to the network just fine. There is no kernel crash or call trace in the logs.