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High · 7.8 CVE-2023-53692 EUVD-2023-60036GHSA-f427-wg66-92gr

ext4: fix use-after-free read in ext4_find_extent for bigalloc + inline

Published Oct 22, 2025 · Updated Aug 5, 2026 · Assigned by Linux

Vendor: Linux Product: Linux Package: linux Package: linux Package: linux-allwinner-5.19 Package: linux-aws Package: linux-aws-5.0 Package: linux-aws-5.11 Package: linux-aws-5.13 Package: linux-aws-5.15 Package: linux-aws-5.19 Package: linux-aws-5.3 Package: linux-aws-5.4 Package: linux-aws-5.8 Package: linux-aws-6.2 Package: linux-aws-6.5 Package: linux-aws-fips Package: linux-azure Package: linux-azure-5.11 Package: linux-azure-5.13 Package: linux-azure-5.15 Package: linux-azure-5.19 Package: linux-azure-5.3 Package: linux-azure-5.4 Package: linux-azure-5.8 Package: linux-azure-6.11 Package: linux-azure-6.2 Package: linux-azure-6.5 Package: linux-azure-edge Package: linux-azure-fde Package: linux-azure-fde-5.19 Package: linux-azure-fde-6.2 Package: linux-azure-fips Package: linux-bluefield Package: linux-fips Package: linux-gcp Package: linux-gcp-5.11 Package: linux-gcp-5.13 Package: linux-gcp-5.15 Package: linux-gcp-5.19 Package: linux-gcp-5.3 Package: linux-gcp-5.4 Package: linux-gcp-5.8 Package: linux-gcp-6.11 Package: linux-gcp-6.2 Package: linux-gcp-6.5 Package: linux-gcp-fips Package: linux-gke Package: linux-gke-4.15 Package: linux-gke-5.15 Package: linux-gke-5.4 Package: linux-gkeop Package: linux-gkeop-5.15 Package: linux-gkeop-5.4 Package: linux-hwe Package: linux-hwe-5.11 Package: linux-hwe-5.13 Package: linux-hwe-5.15 Package: linux-hwe-5.19 Package: linux-hwe-5.4 Package: linux-hwe-5.8 Package: linux-hwe-6.11 Package: linux-hwe-6.2 Package: linux-hwe-6.5 Package: linux-hwe-edge Package: linux-ibm Package: linux-ibm-5.15 Package: linux-ibm-5.4 Package: linux-intel-5.13 Package: linux-intel-iot-realtime Package: linux-intel-iotg Package: linux-intel-iotg-5.15 Package: linux-iot Package: linux-kvm Package: linux-lowlatency Package: linux-lowlatency-hwe-5.15 Package: linux-lowlatency-hwe-5.19 Package: linux-lowlatency-hwe-6.11 Package: linux-lowlatency-hwe-6.2 Package: linux-lowlatency-hwe-6.5 Package: linux-nvidia Package: linux-nvidia-6.2 Package: linux-nvidia-6.5 Package: linux-nvidia-tegra Package: linux-nvidia-tegra-5.15 Package: linux-nvidia-tegra-igx Package: linux-oem Package: linux-oem-5.10 Package: linux-oem-5.13 Package: linux-oem-5.14 Package: linux-oem-5.17 Package: linux-oem-5.6 Package: linux-oem-6.0 Package: linux-oem-6.1 Package: linux-oem-6.11 Package: linux-oem-6.5 Package: linux-oem-6.8 Package: linux-oracle Package: linux-oracle-5.0 Package: linux-oracle-5.11 Package: linux-oracle-5.13 Package: linux-oracle-5.15 Package: linux-oracle-5.3 Package: linux-oracle-5.4 Package: linux-oracle-5.8 Package: linux-oracle-6.5 Package: linux-raspi Package: linux-raspi-5.4 Package: linux-raspi-realtime Package: linux-raspi2 Package: linux-realtime Package: linux-riscv Package: linux-riscv-5.11 Package: linux-riscv-5.15 Package: linux-riscv-5.19 Package: linux-riscv-5.8 Package: linux-riscv-6.5 Package: linux-starfive-5.19 Package: linux-starfive-6.2 Package: linux-starfive-6.5 Package: linux-vmware Package: linux-xilinx-zynqmp Platform: Linux Ecosystem: Debian Ecosystem: Ubuntu

Description

In the Linux kernel, the following vulnerability has been resolved:

ext4: fix use-after-free read in ext4_find_extent for bigalloc + inline

Syzbot found the following issue:
loop0: detected capacity change from 0 to 2048
EXT4-fs (loop0): mounted filesystem 00000000-0000-0000-0000-000000000000 without journal. Quota mode: none.
==================================================================
BUG: KASAN: use-after-free in ext4_ext_binsearch_idx fs/ext4/extents.c:768 [inline]
BUG: KASAN: use-after-free in ext4_find_extent+0x76e/0xd90 fs/ext4/extents.c:931
Read of size 4 at addr ffff888073644750 by task syz-executor420/5067

CPU: 0 PID: 5067 Comm: syz-executor420 Not tainted 6.2.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x1b1/0x290 lib/dump_stack.c:106
print_address_description+0x74/0x340 mm/kasan/report.c:306
print_report+0x107/0x1f0 mm/kasan/report.c:417
kasan_report+0xcd/0x100 mm/kasan/report.c:517
ext4_ext_binsearch_idx fs/ext4/extents.c:768 [inline]
ext4_find_extent+0x76e/0xd90 fs/ext4/extents.c:931
ext4_clu_mapped+0x117/0x970 fs/ext4/extents.c:5809
ext4_insert_delayed_block fs/ext4/inode.c:1696 [inline]
ext4_da_map_blocks fs/ext4/inode.c:1806 [inline]
ext4_da_get_block_prep+0x9e8/0x13c0 fs/ext4/inode.c:1870
ext4_block_write_begin+0x6a8/0x2290 fs/ext4/inode.c:1098
ext4_da_write_begin+0x539/0x760 fs/ext4/inode.c:3082
generic_perform_write+0x2e4/0x5e0 mm/filemap.c:3772
ext4_buffered_write_iter+0x122/0x3a0 fs/ext4/file.c:285
ext4_file_write_iter+0x1d0/0x18f0
call_write_iter include/linux/fs.h:2186 [inline]
new_sync_write fs/read_write.c:491 [inline]
vfs_write+0x7dc/0xc50 fs/read_write.c:584
ksys_write+0x177/0x2a0 fs/read_write.c:637
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f4b7a9737b9
RSP: 002b:00007ffc5cac3668 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f4b7a9737b9
RDX: 00000000175d9003 RSI: 0000000020000200 RDI: 0000000000000004
RBP: 00007f4b7a933050 R08: 0000000000000000 R09: 0000000000000000
R10: 000000000000079f R11: 0000000000000246 R12: 00007f4b7a9330e0
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
</TASK>

Above issue is happens when enable bigalloc and inline data feature. As
commit 131294c35ed6 fixed delayed allocation bug in ext4_clu_mapped for
bigalloc + inline. But it only resolved issue when has inline data, if
inline data has been converted to extent(ext4_da_convert_inline_data_to_extent)
before writepages, there is no EXT4_STATE_MAY_INLINE_DATA flag. However
i_data is still store inline data in this scene. Then will trigger UAF
when find extent.
To resolve above issue, there is need to add judge "ext4_has_inline_data(inode)"
in ext4_clu_mapped().

Affected products

VendorProductAffectedFixed
Linux Linux 4.19.270 – < 4.19.271, 5.4.229 – < 5.4.243, 5.10.163 – < 5.10.180, 5.15.87 – < 5.15.111, 6.1.4 – < 6.1.28, 6.0.18 – < 6.1, 6.2 4.19.271

Fixed in Linux distributions

Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.

ReleasePackageFixed inAdvisory
Debian 14 linux 6.3.7-1 —
Debian 13 linux 6.3.7-1 —
Debian 12 linux 6.1.37-1 —
ReleasePackageFixed inAdvisory
Ubuntu Nvidia-BlueField 22.04 LTS linux-bluefield 5.15.0-1022.24 —
Ubuntu 24.04 LTS linux-riscv +8 No fix yet —
Ubuntu 22.04 LTS linux 5.15.0-79.86 —
Ubuntu 22.04 LTS linux-aws 5.15.0-1042.47 —
Ubuntu 22.04 LTS linux-azure 5.15.0-1045.52 —
Ubuntu 22.04 LTS linux-azure-fde 5.15.0-1045.52.1 —
Ubuntu 22.04 LTS linux-gcp 5.15.0-1039.47 —
Ubuntu 22.04 LTS linux-gke +1 5.15.0-1039.44 —
Ubuntu 22.04 LTS linux-gkeop 5.15.0-1025.30 —
Ubuntu 22.04 LTS linux-ibm +1 5.15.0-1035.38 —
Ubuntu 22.04 LTS linux-intel-iotg 5.15.0-1037.42 —
Ubuntu 22.04 LTS linux-lowlatency 5.15.0-79.88 —
Ubuntu 22.04 LTS linux-nvidia 5.15.0-1030.30 —
Ubuntu 22.04 LTS linux-nvidia-tegra 5.15.0-1016.16 —
Ubuntu 22.04 LTS linux-nvidia-tegra-igx 5.15.0-1002.2 —
Ubuntu 22.04 LTS linux-oracle 5.15.0-1040.46 —
Ubuntu 22.04 LTS linux-riscv +32 No fix yet —
Ubuntu 22.04 LTS linux-xilinx-zynqmp 5.15.0-1025.29 —
Ubuntu 20.04 LTS linux 5.4.0-162.179 —
Ubuntu 20.04 LTS linux-aws 5.4.0-1109.118 —
Ubuntu 20.04 LTS linux-aws-5.15 5.15.0-1041.46~20.04.1 —
Ubuntu 20.04 LTS linux-azure 5.4.0-1115.122 —
Ubuntu 20.04 LTS linux-azure-5.15 5.15.0-1045.52~20.04.1 —
Ubuntu 20.04 LTS linux-bluefield 5.4.0-1070.76 —
Ubuntu 20.04 LTS linux-gcp 5.4.0-1112.121 —
Ubuntu 20.04 LTS linux-gcp-5.15 5.15.0-1039.47~20.04.1 —
Ubuntu 20.04 LTS linux-gke +28 No fix yet —
Ubuntu 20.04 LTS linux-hwe-5.15 5.15.0-79.86~20.04.2 —
Ubuntu 20.04 LTS linux-ibm 5.4.0-1056.61 —
Ubuntu 20.04 LTS linux-ibm-5.15 5.15.0-1036.39~20.04.1 —
Ubuntu 20.04 LTS linux-intel-iotg-5.15 5.15.0-1037.42~20.04.1 —
Ubuntu 20.04 LTS linux-iot 5.4.0-1021.22 —
Ubuntu 20.04 LTS linux-kvm 5.4.0-1098.104 —
Ubuntu 20.04 LTS linux-lowlatency-hwe-5.15 5.15.0-79.88~20.04.1 —
Ubuntu 20.04 LTS linux-nvidia-tegra-5.15 5.15.0-1016.16~20.04.1 —
Ubuntu 20.04 LTS linux-oracle 5.4.0-1108.117 —
Ubuntu 20.04 LTS linux-oracle-5.15 5.15.0-1040.46~20.04.1 —
Ubuntu 20.04 LTS linux-raspi 5.4.0-1093.104 —
Ubuntu 20.04 LTS linux-riscv-5.15 5.15.0-1038.42~20.04.2 —
Ubuntu 20.04 LTS linux-xilinx-zynqmp 5.4.0-1029.33 —
Ubuntu 18.04 LTS linux-gcp +14 No fix yet —
Show 5 more (older releases, extended support, other products)
ReleasePackageFixed inAdvisory
Ubuntu 16.04 LTS linux-hwe-edge No fix yet —
Ubuntu Pro Realtime 22.04 LTS linux-intel-iot-realtime 5.15.0-1036.38 —
Ubuntu Pro Realtime 22.04 LTS linux-realtime 5.15.0-1043.48 —
Ubuntu Pro FIPS-updates 20.04 LTS linux-aws-fips 5.4.0-1109.118+fips1 —
Ubuntu Pro FIPS-updates 20.04 LTS linux-azure-fips 5.4.0-1115.122+fips1 —
Ubuntu Pro FIPS-updates 20.04 LTS linux-fips 5.4.0-1084.93 —
Ubuntu Pro FIPS-updates 20.04 LTS linux-gcp-fips 5.4.0-1112.121+fips1 —
Ubuntu Pro FIPS-preview 22.04 LTS linux-fips No fix yet —
Ubuntu Pro 18.04 LTS linux-aws-5.4 5.4.0-1109.118~18.04.1 —
Ubuntu Pro 18.04 LTS linux-azure-5.4 5.4.0-1115.122~18.04.1 —
Ubuntu Pro 18.04 LTS linux-gcp-5.4 5.4.0-1112.121~18.04.1 —
Ubuntu Pro 18.04 LTS linux-hwe-5.4 5.4.0-162.179~18.04.1 —
Ubuntu Pro 18.04 LTS linux-ibm-5.4 5.4.0-1056.61~18.04.1 —
Ubuntu Pro 18.04 LTS linux-oracle-5.4 5.4.0-1108.117~18.04.1 —
Ubuntu Pro 18.04 LTS linux-raspi-5.4 5.4.0-1093.104~18.04.1 —
ReleasePackageFixed inAdvisory
SLES 15 SP5 kernel-64kb +6 5.14.21-150500.55.127.1 SUSE-SU-2025:4320-1
SLES 15 SP5 kernel-default-base 5.14.21-150500.55.127.1.150500.6.61.1 SUSE-SU-2025:4320-1
SLES 15 SP4 kernel-64kb +6 5.14.21-150400.24.184.1 SUSE-SU-2025:4111-1
SLES 15 SP4 kernel-default-base 5.14.21-150400.24.184.1.150400.24.94.2 SUSE-SU-2025:4111-1
Show 11 more (older releases, extended support, other products)
ReleasePackageFixed inAdvisory
SLES for SAP 15 SP5 kernel-default-base 5.14.21-150500.55.127.1.150500.6.61.1 SUSE-SU-2025:4320-1
SLES for SAP 15 SP5 kernel-docs +4 5.14.21-150500.55.127.1 SUSE-SU-2025:4320-1
SLES for SAP 15 SP4 kernel-default-base 5.14.21-150400.24.184.1.150400.24.94.2 SUSE-SU-2025:4111-1
SLES for SAP 15 SP4 kernel-docs +4 5.14.21-150400.24.184.1 SUSE-SU-2025:4111-1
SLE Micro 5.5 kernel-default-base 5.14.21-150500.55.127.1.150500.6.61.1 SUSE-SU-2025:4320-1
SLE Micro 5.5 kernel-rt +1 5.14.21-150500.13.112.1 SUSE-SU-2025:4149-1
SLE Micro 5.5 kernel-source +1 5.14.21-150500.55.127.1 SUSE-SU-2025:4320-1
SLE Micro 5.4 kernel-default 5.14.21-150400.24.184.1 SUSE-SU-2025:4111-1
SLE Micro 5.4 kernel-default-base 5.14.21-150400.24.184.1.150400.24.94.2 SUSE-SU-2025:4111-1
SLE Micro 5.4 kernel-rt +1 5.14.21-150400.15.136.1 SUSE-SU-2025:4139-1
SLE Micro 5.3 kernel-default 5.14.21-150400.24.184.1 SUSE-SU-2025:4111-1
SLE Micro 5.3 kernel-default-base 5.14.21-150400.24.184.1.150400.24.94.2 SUSE-SU-2025:4111-1
SLE Micro 5.3 kernel-rt +1 5.14.21-150400.15.136.1 SUSE-SU-2025:4139-1
SLE Live Patching 15 SP5 kernel-default 5.14.21-150500.55.127.1 SUSE-SU-2025:4320-1
SLE Live Patching 15 SP5 kernel-livepatch-SLE15-SP5_Update_32 1-150500.11.3.1 SUSE-SU-2025:4320-1
SLE Live Patching 15 SP4 kernel-default 5.14.21-150400.24.184.1 SUSE-SU-2025:4111-1
SLE Live Patching 15 SP4 kernel-livepatch-SLE15-SP4_Update_46 1-150400.9.5.1 SUSE-SU-2025:4111-1
SLE HPC 15 SP5 kernel-64kb +5 5.14.21-150500.55.127.1 SUSE-SU-2025:4320-1
SLE HPC 15 SP5 kernel-default-base 5.14.21-150500.55.127.1.150500.6.61.1 SUSE-SU-2025:4320-1
SLE HPC 15 SP4 kernel-64kb +5 5.14.21-150400.24.184.1 SUSE-SU-2025:4111-1
SLE HPC 15 SP4 kernel-default-base 5.14.21-150400.24.184.1.150400.24.94.2 SUSE-SU-2025:4111-1
SUSE Manager Server LTS 4.3 kernel-default-base 5.14.21-150400.24.184.1.150400.24.94.2 SUSE-SU-2025:4111-1
SUSE Manager Server LTS 4.3 kernel-syms +3 5.14.21-150400.24.184.1 SUSE-SU-2025:4111-1
SUSE Manager Proxy LTS 4.3 kernel-default-base 5.14.21-150400.24.184.1.150400.24.94.2 SUSE-SU-2025:4111-1
SUSE Manager Proxy LTS 4.3 kernel-syms +2 5.14.21-150400.24.184.1 SUSE-SU-2025:4111-1

Amazon Linux

ReleasePackageFixed inAdvisory
Amazon Linux 2023 kernel-livepatch-6.1.29-47.49 1.0-0.amzn2023 ALAS2023-2023-184
Amazon Linux 2023 perf +12 6.1.29-47.49.amzn2023 ALAS2023-2023-184

Advisories 6

References