# CVE-2021-47302: linux: In the Linux kernel, the following vulnerability has been resolved:  igc: Fix use-after-free error during reset  Clea...

CVE-2021-47302 is fixed in linux on 1 platform, first by DEBIAN-CVE-2021-47302, released May 21, 2024. It is not reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/cve/CVE-2021-47302
- Priority: High
- CVSS: 7.8 (high)
- EPSS: 0.0023
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: May 21, 2024

## Description

In the Linux kernel, the following vulnerability has been resolved:  igc: Fix use-after-free error during reset  Cleans the next descriptor to watch (next_to_watch) when cleaning the TX ring.  Failure to do so can cause invalid memory accesses. If igc_poll() runs while the controller is being reset this can lead to the driver try to free a skb that was already freed.  Log message:   [  101.525242] refcount_t: underflow; use-after-free.  [  101.525251] WARNING: CPU: 1 PID: 646 at lib/refcount.c:28 refcount_warn_saturate+0xab/0xf0  [  101.525259] Modules linked in: sch_etf(E) sch_mqprio(E) rfkill(E) intel_rapl_msr(E) intel_rapl_common(E)  x86_pkg_temp_thermal(E) intel_powerclamp(E) coretemp(E) binfmt_misc(E) kvm_intel(E) kvm(E) irqbypass(E) crc32_pclmul(E)  ghash_clmulni_intel(E) aesni_intel(E) mei_wdt(E) libaes(E) crypto_simd(E) cryptd(E) glue_helper(E) snd_hda_codec_hdmi(E)  rapl(E) intel_cstate(E) snd_hda_intel(E) snd_intel_dspcfg(E) sg(E) soundwire_intel(E) intel_uncore(E) at24(E)  soundwire_generic_allocation(E) iTCO_wdt(E) soundwire_cadence(E) intel_pmc_bxt(E) serio_raw(E) snd_hda_codec(E)  iTCO_vendor_support(E) watchdog(E) snd_hda_core(E) snd_hwdep(E) snd_soc_core(E) snd_compress(E) snd_pcsp(E)  soundwire_bus(E) snd_pcm(E) evdev(E) snd_timer(E) mei_me(E) snd(E) soundcore(E) mei(E) configfs(E) ip_tables(E) x_tables(E)  autofs4(E) ext4(E) crc32c_generic(E) crc16(E) mbcache(E) jbd2(E) sd_mod(E) t10_pi(E) crc_t10dif(E) crct10dif_generic(E)  i915(E) ahci(E) libahci(E) ehci_pci(E) igb(E) xhci_pci(E) ehci_hcd(E)  [  101.525303]  drm_kms_helper(E) dca(E) xhci_hcd(E) libata(E) crct10dif_pclmul(E) cec(E) crct10dif_common(E) tsn(E) igc(E)  e1000e(E) ptp(E) i2c_i801(E) crc32c_intel(E) psmouse(E) i2c_algo_bit(E) i2c_smbus(E) scsi_mod(E) lpc_ich(E) pps_core(E)  usbcore(E) drm(E) button(E) video(E)  [  101.525318] CPU: 1 PID: 646 Comm: irq/37-enp7s0-T Tainted: G            E     5.10.30-rt37-tsn1-rt-ipipe #ipipe  [  101.525320] Hardware name: SIEMENS AG SIMATIC IPC427D/A5E31233588, BIOS V17.02.09 03/31/2017  [  101.525322] RIP: 0010:refcount_warn_saturate+0xab/0xf0  [  101.525325] Code: 05 31 48 44 01 01 e8 f0 c6 42 00 0f 0b c3 80 3d 1f 48 44 01 00 75 90 48 c7 c7 78 a8 f3 a6 c6 05 0f 48  44 01 01 e8 d1 c6 42 00 <0f> 0b c3 80 3d fe 47 44 01 00 0f 85 6d ff ff ff 48 c7 c7 d0 a8 f3  [  101.525327] RSP: 0018:ffffbdedc0917cb8 EFLAGS: 00010286  [  101.525329] RAX: 0000000000000000 RBX: ffff98fd6becbf40 RCX: 0000000000000001  [  101.525330] RDX: 0000000000000001 RSI: ffffffffa6f2700c RDI: 00000000ffffffff  [  101.525332] RBP: ffff98fd6becc14c R08: ffffffffa7463d00 R09: ffffbdedc0917c50  [  101.525333] R10: ffffffffa74c3578 R11: 0000000000000034 R12: 00000000ffffff00  [  101.525335] R13: ffff98fd6b0b1000 R14: 0000000000000039 R15: ffff98fd6be35c40  [  101.525337] FS:  0000000000000000(0000) GS:ffff98fd6e240000(0000) knlGS:0000000000000000  [  101.525339] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033  [  101.525341] CR2: 00007f34135a3a70 CR3: 0000000150210003 CR4: 00000000001706e0  [  101.525343] Call Trace:  [  101.525346]  sock_wfree+0x9c/0xa0  [  101.525353]  unix_destruct_scm+0x7b/0xa0  [  101.525358]  skb_release_head_state+0x40/0x90  [  101.525362]  skb_release_all+0xe/0x30  [  101.525364]  napi_consume_skb+0x57/0x160  [  101.525367]  igc_poll+0xb7/0xc80 [igc]  [  101.525376]  ? sched_clock+0x5/0x10  [  101.525381]  ? sched_clock_cpu+0xe/0x100  [  101.525385]  net_rx_action+0x14c/0x410  [  101.525388]  __do_softirq+0xe9/0x2f4  [  101.525391]  __local_bh_enable_ip+0xe3/0x110  [  101.525395]  ? irq_finalize_oneshot.part.47+0xe0/0xe0  [  101.525398]  irq_forced_thread_fn+0x6a/0x80  [  101.525401]  irq_thread+0xe8/0x180  [  101.525403]  ? wake_threads_waitq+0x30/0x30  [  101.525406]  ? irq_thread_check_affinity+0xd0/0xd0  [  101.525408]  kthread+0x183/0x1a0  [  101.525412]  ? kthread_park+0x80/0x80  [  101.525415]  ret_from_fork+0x22/0x30

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | linux Debian 12.15 (bookworm) | 5.14.6-1 | [DEBIAN-CVE-2021-47302](https://patchblox.com/security/data/fix/linux/debian-cve-2021-47302.md) | May 21, 2024 |
| Linux | linux Debian 13.5 (trixie) | 5.14.6-1 | [DEBIAN-CVE-2021-47302](https://patchblox.com/security/data/fix/linux/debian-cve-2021-47302.md) | May 21, 2024 |
| Linux | linux Debian 14 | 5.14.6-1 | [DEBIAN-CVE-2021-47302](https://patchblox.com/security/data/fix/linux/debian-cve-2021-47302.md) | May 21, 2024 |

---

Data as of 2026-11-08T13:06:02Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

Free to use with attribution: show "Data: Patchblox Patch Radar" with a link to https://patchblox.com/security/patch-radar. Terms, including what needs a written agreement: https://patchblox.com/security/patch-radar/use-the-data

Product names, logos and trademarks shown on Patch Radar belong to their respective owners. They are used only to identify the software each security fix applies to and to help readers find their platform. Their use does not imply any affiliation with, or endorsement by, those owners, and Patchblox is not affiliated with any of them.