🛡️ UBUNTU-CVE-2021-47256
⚪ Unknown ✅ No Known Exploit OSV
N/A
CVSS Score
0 Low4 Medium7 High9 Critical10

Description

In the Linux kernel, the following vulnerability has been resolved: mm/memory-failure: make sure wait for page writeback in memory_failure Our syzkaller trigger the "BUG_ON(!list_empty(&inode->i_wb_list))" in clear_inode: kernel BUG at fs/inode.c:519! Internal error: Oops - BUG: 0 [#1] SMP Modules linked in: Process syz-executor.0 (pid: 249, stack limit = 0x00000000a12409d7) CPU: 1 PID: 249 Comm: syz-executor.0 Not tainted 4.19.95 Hardware name: linux,dummy-virt (DT) pstate: 80000005 (Nzcv daif -PAN -UAO) pc : clear_inode+0x280/0x2a8 lr : clear_inode+0x280/0x2a8 Call trace: clear_inode+0x280/0x2a8 ext4_clear_inode+0x38/0xe8 ext4_free_inode+0x130/0xc68 ext4_evict_inode+0xb20/0xcb8 evict+0x1a8/0x3c0 iput+0x344/0x460 do_unlinkat+0x260/0x410 __arm64_sys_unlinkat+0x6c/0xc0 el0_svc_common+0xdc/0x3b0 el0_svc_handler+0xf8/0x160 el0_svc+0x10/0x218 Kernel panic - not syncing: Fatal exception A crash dump of this problem show that someone called __munlock_pagevec to clear page LRU without lock_page: do_mmap -> mmap_region -> do_munmap -> munlock_vma_pages_range -> __munlock_pagevec. As a result memory_failure will call identify_page_state without wait_on_page_writeback. And after truncate_error_page clear the mapping of this page. end_page_writeback won't call sb_clear_inode_writeback to clear inode->i_wb_list. That will trigger BUG_ON in clear_inode! Fix it by checking PageWriteback too to help determine should we skip wait_on_page_writeback.

Details

Severity Unknown
CVSS Score N/A
CVSS Vector CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
CWE N/A
Public Exploit ✅ No
Source OSV
Published 2024-05-21
Updated 2026-06-15
Modified 2026-06-04
Fix URL N/A

Affected Packages

Software From version Fixed in
linux 5.4.0-81.91
linux-allwinner-5.19
linux-aws 5.4.0-1055.58
linux-aws-5.0
linux-aws-5.11
linux-aws-5.13
linux-aws-5.19
linux-aws-5.3
linux-aws-5.4 5.4.0-1055.58~18.04.1
linux-aws-5.8
linux-aws-6.2
linux-aws-fips
linux-aws-hwe 4.15.0-1111.118~16.04.1
linux-azure 5.4.0-1056.58
linux-azure-4.15 4.15.0-1123.136
linux-azure-5.11
linux-azure-5.13
linux-azure-5.19
linux-azure-5.3
linux-azure-5.4 5.4.0-1056.58~18.04.1
linux-azure-5.8
linux-azure-6.2
linux-azure-edge
linux-azure-fde
linux-azure-fde-5.19
linux-azure-fde-6.2
linux-azure-fips
linux-bluefield
linux-fips
linux-gcp 5.4.0-1051.55
linux-gcp-4.15 4.15.0-1108.122
linux-gcp-5.11
linux-gcp-5.13
linux-gcp-5.19
linux-gcp-5.3
linux-gcp-5.4 5.4.0-1051.55~18.04.1
linux-gcp-5.8
linux-gcp-6.2
linux-gcp-fips
linux-gke
linux-gke-4.15
linux-gke-5.15
linux-gke-5.4
linux-gkeop 5.4.0-1022.23
linux-gkeop-5.4
linux-hwe
linux-hwe-5.11
linux-hwe-5.13
linux-hwe-5.19
linux-hwe-5.4 5.4.0-81.91~18.04.1
linux-hwe-5.8
linux-hwe-6.2
linux-hwe-edge
linux-intel-5.13
linux-intel-iot-realtime
linux-kvm 5.4.0-1045.47
linux-lowlatency-hwe-5.19
linux-lowlatency-hwe-6.2
linux-lts-xenial
linux-nvidia
linux-nvidia-6.2
linux-oem
linux-oem-5.10
linux-oem-5.13
linux-oem-5.14
linux-oem-5.17
linux-oem-5.6
linux-oem-6.0
linux-oem-6.1
linux-oracle 5.4.0-1053.57
linux-oracle-5.0
linux-oracle-5.11
linux-oracle-5.13
linux-oracle-5.3
linux-oracle-5.4 5.4.0-1053.57~18.04.1
linux-oracle-5.8
linux-raspi 5.4.0-1042.46
linux-raspi-5.4 5.4.0-1042.46~18.04.3
linux-raspi-realtime
linux-raspi2
linux-realtime
linux-riscv
linux-riscv-5.11
linux-riscv-5.19
linux-riscv-5.8
linux-starfive-5.19
linux-starfive-6.2

Similar Threats

Vulnerability Monitoring

Stay informed about vulnerabilities in your stack

BotEraser monitors your WordPress installation and notifies you when software you use appears in our vulnerability database.

Set Up Free Alerts →

No credit card required  ·  Results in minutes

ⓘ Data Notice: The information presented above has been compiled from publicly available internet sources. Boteraser aggregates this data solely for informational purposes and does not independently classify, evaluate, or endorse any findings about the vulnerabilities listed. The accuracy and completeness of this information is the sole responsibility of the original publishers. Boteraser and its operators accept no liability for any decisions made based on this data.