Log in Start free

Vulnerability · Published Sep 16, 2025 · Assigned by Linux

CVE-2022-50344ext4: fix null-ptr-deref in ext4_write_info

Medium 5.5

In plain English

A medium-severity null pointer dereference in Linux from Linux. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 6% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)5.5Medium
Exploit odds (30 days)0.2%top 94.4% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

Official description

In the Linux kernel, the following vulnerability has been resolved: ext4: fix null-ptr-deref in ext4_write_info I caught a null-ptr-deref bug as follows: ================================================================== KASAN: null-ptr-deref in range [0x0000000000000068-0x000000000000006f] CPU: 1 PID: 1589 Comm: umount Not tainted 5.10.0-02219-dirty #339 RIP: 0010:ext4_write_info+0x53/0x1b0 [...] Call Trace: dquot_writeback_dquots+0x341/0x9a0 ext4_sync_fs+0x19e/0x800 __sync_filesystem+0x83/0x100 sync_filesystem+0x89/0xf0 generic_shutdown_super+0x79/0x3e0 kill_block_super+0xa1/0x110 deactivate_locked_super+0xac/0x130 deactivate_super+0xb6/0xd0 cleanup_mnt+0x289/0x400 __cleanup_mnt+0x16/0x20 task_work_run+0x11c/0x1c0 exit_to_user_mode_prepare+0x203/0x210 syscall_exit_to_user_mode+0x5b/0x3a0 do_syscall_64+0x59/0x70 entry_SYSCALL_64_after_hwframe+0x44/0xa9 ================================================================== Above issue may happen as follows: ------------------------------------- exit_to_user_mode_prepare task_work_run __cleanup_mnt cleanup_mnt deactivate_super deactivate_locked_super kill_block_super generic_shutdown_super shrink_dcache_for_umount dentry = sb->s_root sb->s_root = NULL <--- Here set NULL sync_filesystem __sync_filesystem sb->s_op->sync_fs > ext4_sync_fs dquot_writeback_dquots sb->dq_op->write_info > ext4_write_info ext4_journal_start(d_inode(sb->s_root), EXT4_HT_QUOTA, 2) d_inode(sb->s_root) s_root->d_inode <--- Null pointer dereference To solve this problem, we use ext4_journal_start_sb directly to avoid s_root being used.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Debian:12linux6.0.3-1DEBIAN-CVE-2022-50344
Debian:13linux6.0.3-1DEBIAN-CVE-2022-50344
Debian:14linux6.0.3-1DEBIAN-CVE-2022-50344
Rocky Linux:8kernel0:4.18.0-553.123.1.el8_10.cloud.0.1RXSA-2024:3138
Ubuntu:22.04:LTSlinux5.15.0-60.66UBUNTU-CVE-2022-50344
Ubuntu:22.04:LTSlinux-allwinner-5.19no fix listedUBUNTU-CVE-2022-50344
Ubuntu:22.04:LTSlinux-aws5.15.0-1030.34UBUNTU-CVE-2022-50344
Ubuntu:22.04:LTSlinux-aws-5.19no fix listedUBUNTU-CVE-2022-50344
Ubuntu:22.04:LTSlinux-aws-6.2no fix listedUBUNTU-CVE-2022-50344
Ubuntu:22.04:LTSlinux-aws-6.5no fix listedUBUNTU-CVE-2022-50344
Ubuntu:22.04:LTSlinux-azure5.15.0-1033.40UBUNTU-CVE-2022-50344
Ubuntu:22.04:LTSlinux-azure-5.19no fix listedUBUNTU-CVE-2022-50344
Ubuntu:24.04:LTSlinux-azure-6.11no fix listedUBUNTU-CVE-2022-50344
Ubuntu:22.04:LTSlinux-azure-6.2no fix listedUBUNTU-CVE-2022-50344
Ubuntu:22.04:LTSlinux-azure-6.5no fix listedUBUNTU-CVE-2022-50344
Ubuntu:22.04:LTSlinux-azure-fde5.15.0-1033.40.1UBUNTU-CVE-2022-50344
Ubuntu:22.04:LTSlinux-azure-fde-5.19no fix listedUBUNTU-CVE-2022-50344
Ubuntu:22.04:LTSlinux-azure-fde-6.2no fix listedUBUNTU-CVE-2022-50344
Ubuntu:22.04:LTSlinux-gcp5.15.0-1029.36UBUNTU-CVE-2022-50344
Ubuntu:22.04:LTSlinux-gcp-5.19no fix listedUBUNTU-CVE-2022-50344
Ubuntu:24.04:LTSlinux-gcp-6.11no fix listedUBUNTU-CVE-2022-50344
Ubuntu:22.04:LTSlinux-gcp-6.2no fix listedUBUNTU-CVE-2022-50344
Ubuntu:22.04:LTSlinux-gcp-6.5no fix listedUBUNTU-CVE-2022-50344
Ubuntu:22.04:LTSlinux-gke5.15.0-1027.32UBUNTU-CVE-2022-50344
Ubuntu:22.04:LTSlinux-gkeop5.15.0-1015.19UBUNTU-CVE-2022-50344
Ubuntu:22.04:LTSlinux-hwe-5.19no fix listedUBUNTU-CVE-2022-50344
Ubuntu:24.04:LTSlinux-hwe-6.11no fix listedUBUNTU-CVE-2022-50344
Ubuntu:22.04:LTSlinux-hwe-6.2no fix listedUBUNTU-CVE-2022-50344
Ubuntu:22.04:LTSlinux-hwe-6.5no fix listedUBUNTU-CVE-2022-50344
Ubuntu:22.04:LTSlinux-ibm5.15.0-1025.28UBUNTU-CVE-2022-50344
Ubuntu:24.04:LTSlinux-intelno fix listedUBUNTU-CVE-2022-50344
Ubuntu:22.04:LTSlinux-intel-iot-realtimeno fix listedUBUNTU-CVE-2022-50344
Ubuntu:22.04:LTSlinux-intel-iotg5.15.0-1025.30UBUNTU-CVE-2022-50344
Ubuntu:22.04:LTSlinux-kvm5.15.0-1028.33UBUNTU-CVE-2022-50344
Ubuntu:22.04:LTSlinux-lowlatency5.15.0-60.66UBUNTU-CVE-2022-50344
Ubuntu:22.04:LTSlinux-lowlatency-hwe-5.19no fix listedUBUNTU-CVE-2022-50344
Ubuntu:24.04:LTSlinux-lowlatency-hwe-6.11no fix listedUBUNTU-CVE-2022-50344
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.2no fix listedUBUNTU-CVE-2022-50344
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.5no fix listedUBUNTU-CVE-2022-50344
Ubuntu:22.04:LTSlinux-nvidia5.15.0-1017.17UBUNTU-CVE-2022-50344
Ubuntu:22.04:LTSlinux-nvidia-6.2no fix listedUBUNTU-CVE-2022-50344
Ubuntu:22.04:LTSlinux-nvidia-6.5no fix listedUBUNTU-CVE-2022-50344
Ubuntu:22.04:LTSlinux-oem-5.17no fix listedUBUNTU-CVE-2022-50344
Ubuntu:22.04:LTSlinux-oem-6.0no fix listedUBUNTU-CVE-2022-50344
Ubuntu:22.04:LTSlinux-oem-6.1no fix listedUBUNTU-CVE-2022-50344
Ubuntu:24.04:LTSlinux-oem-6.11no fix listedUBUNTU-CVE-2022-50344
Ubuntu:22.04:LTSlinux-oem-6.5no fix listedUBUNTU-CVE-2022-50344
Ubuntu:24.04:LTSlinux-oem-6.8no fix listedUBUNTU-CVE-2022-50344
Ubuntu:22.04:LTSlinux-oracle5.15.0-1029.35UBUNTU-CVE-2022-50344
Ubuntu:22.04:LTSlinux-oracle-6.5no fix listedUBUNTU-CVE-2022-50344
Ubuntu:22.04:LTSlinux-raspi5.15.0-1024.26UBUNTU-CVE-2022-50344
Ubuntu:24.04:LTSlinux-raspi-realtimeno fix listedUBUNTU-CVE-2022-50344
Ubuntu:22.04:LTSlinux-realtimeno fix listedUBUNTU-CVE-2022-50344
Ubuntu:24.04:LTSlinux-realtimeno fix listedUBUNTU-CVE-2022-50344
Ubuntu:22.04:LTSlinux-riscvno fix listedUBUNTU-CVE-2022-50344
Ubuntu:24.04:LTSlinux-riscvno fix listedUBUNTU-CVE-2022-50344
Ubuntu:22.04:LTSlinux-riscv-5.19no fix listedUBUNTU-CVE-2022-50344
Ubuntu:22.04:LTSlinux-riscv-6.5no fix listedUBUNTU-CVE-2022-50344
Ubuntu:22.04:LTSlinux-starfive-5.19no fix listedUBUNTU-CVE-2022-50344
Ubuntu:22.04:LTSlinux-starfive-6.2no fix listedUBUNTU-CVE-2022-50344
Ubuntu:22.04:LTSlinux-starfive-6.5no fix listedUBUNTU-CVE-2022-50344

Affected products (as reported)

VendorProductVersions
Linux Linux a1177825719ccef3f76ef39bbfd5ebb6087d53c7 – before dc451578446afd03c0c21913993c08898a691435a1177825719ccef3f76ef39bbfd5ebb6087d53c7 – before f4b5ff0b794aa94afac7269c494550ca2f66511ba1177825719ccef3f76ef39bbfd5ebb6087d53c7 – before 947264e00c46de19a016fd81218118c708fed2f3a1177825719ccef3f76ef39bbfd5ebb6087d53c7 – before 3638aa1c7d87c0ca0aef23cf58cae2c48e7daca4a1177825719ccef3f76ef39bbfd5ebb6087d53c7 – before f34ab95162763cd7352f46df169296eec28b688da1177825719ccef3f76ef39bbfd5ebb6087d53c7 – before 533c60a0b97cee5daab376933f486207e6680fb7a1177825719ccef3f76ef39bbfd5ebb6087d53c7 – before 4a657319cfabd6199fd0b7b65bbebf6ded7a11c1a1177825719ccef3f76ef39bbfd5ebb6087d53c7 – before bb420e8afc854d2a1caaa23a0c129839acfb7888
Linux Linux 3.6

Weakness: CWE-476 · Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

References