Vulnerability · Published Feb 26, 2025 · Assigned by Linux

CVE-2022-49707ext4: add reserved GDT blocks check

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 0.3% (higher than 21% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)5.5Medium
Exploit odds (30 days)0.3%top 79.4% 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: add reserved GDT blocks check We capture a NULL pointer issue when resizing a corrupt ext4 image which is freshly clear resize_inode feature (not run e2fsck). It could be simply reproduced by following steps. The problem is because of the resize_inode feature was cleared, and it will convert the filesystem to meta_bg mode in ext4_resize_fs(), but the es->s_reserved_gdt_blocks was not reduced to zero, so could we mistakenly call reserve_backup_gdb() and passing an uninitialized resize_inode to it when adding new group descriptors. mkfs.ext4 /dev/sda 3G tune2fs -O ^resize_inode /dev/sda #forget to run requested e2fsck mount /dev/sda /mnt resize2fs /dev/sda 8G ======== BUG: kernel NULL pointer dereference, address: 0000000000000028 CPU: 19 PID: 3243 Comm: resize2fs Not tainted 5.18.0-rc7-00001-gfde086c5ebfd #748 ... RIP: 0010:ext4_flex_group_add+0xe08/0x2570 ... Call Trace: <TASK> ext4_resize_fs+0xbec/0x1660 __ext4_ioctl+0x1749/0x24e0 ext4_ioctl+0x12/0x20 __x64_sys_ioctl+0xa6/0x110 do_syscall_64+0x3b/0x90 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f2dd739617b ======== The fix is simple, add a check in ext4_resize_begin() to make sure that the es->s_reserved_gdt_blocks is zero when the resize_inode feature is disabled.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Debian:12linux5.18.14-1DEBIAN-CVE-2022-49707
Debian:13linux5.18.14-1DEBIAN-CVE-2022-49707
Debian:14linux5.18.14-1DEBIAN-CVE-2022-49707
Ubuntu:22.04:LTSlinux5.15.0-48.54UBUNTU-CVE-2022-49707
Ubuntu:22.04:LTSlinux-allwinner-5.19no fix listedUBUNTU-CVE-2022-49707
Ubuntu:22.04:LTSlinux-aws5.15.0-1020.24UBUNTU-CVE-2022-49707
Ubuntu:22.04:LTSlinux-aws-5.19no fix listedUBUNTU-CVE-2022-49707
Ubuntu:22.04:LTSlinux-aws-6.2no fix listedUBUNTU-CVE-2022-49707
Ubuntu:22.04:LTSlinux-aws-6.5no fix listedUBUNTU-CVE-2022-49707
Ubuntu:22.04:LTSlinux-azure5.15.0-1020.25UBUNTU-CVE-2022-49707
Ubuntu:22.04:LTSlinux-azure-5.19no fix listedUBUNTU-CVE-2022-49707
Ubuntu:22.04:LTSlinux-azure-6.2no fix listedUBUNTU-CVE-2022-49707
Ubuntu:22.04:LTSlinux-azure-6.5no fix listedUBUNTU-CVE-2022-49707
Ubuntu:22.04:LTSlinux-azure-fde5.15.0-1024.30.1UBUNTU-CVE-2022-49707
Ubuntu:22.04:LTSlinux-azure-fde-5.19no fix listedUBUNTU-CVE-2022-49707
Ubuntu:22.04:LTSlinux-azure-fde-6.2no fix listedUBUNTU-CVE-2022-49707
Ubuntu:22.04:LTSlinux-gcp5.15.0-1018.24UBUNTU-CVE-2022-49707
Ubuntu:22.04:LTSlinux-gcp-5.19no fix listedUBUNTU-CVE-2022-49707
Ubuntu:22.04:LTSlinux-gcp-6.2no fix listedUBUNTU-CVE-2022-49707
Ubuntu:22.04:LTSlinux-gcp-6.5no fix listedUBUNTU-CVE-2022-49707
Ubuntu:22.04:LTSlinux-gke5.15.0-1016.19UBUNTU-CVE-2022-49707
Ubuntu:22.04:LTSlinux-gkeop5.15.0-1003.5UBUNTU-CVE-2022-49707
Ubuntu:22.04:LTSlinux-hwe-5.19no fix listedUBUNTU-CVE-2022-49707
Ubuntu:22.04:LTSlinux-hwe-6.2no fix listedUBUNTU-CVE-2022-49707
Ubuntu:22.04:LTSlinux-hwe-6.5no fix listedUBUNTU-CVE-2022-49707
Ubuntu:22.04:LTSlinux-ibm5.15.0-1015.17UBUNTU-CVE-2022-49707
Ubuntu:22.04:LTSlinux-intel-iot-realtimeno fix listedUBUNTU-CVE-2022-49707
Ubuntu:22.04:LTSlinux-intel-iotg5.15.0-1016.21UBUNTU-CVE-2022-49707
Ubuntu:22.04:LTSlinux-kvm5.15.0-1018.22UBUNTU-CVE-2022-49707
Ubuntu:22.04:LTSlinux-lowlatency5.15.0-48.54UBUNTU-CVE-2022-49707
Ubuntu:22.04:LTSlinux-lowlatency-hwe-5.19no fix listedUBUNTU-CVE-2022-49707
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.2no fix listedUBUNTU-CVE-2022-49707
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.5no fix listedUBUNTU-CVE-2022-49707
Ubuntu:22.04:LTSlinux-nvidia5.15.0-1007.7UBUNTU-CVE-2022-49707
Ubuntu:22.04:LTSlinux-nvidia-6.2no fix listedUBUNTU-CVE-2022-49707
Ubuntu:22.04:LTSlinux-nvidia-6.5no fix listedUBUNTU-CVE-2022-49707
Ubuntu:22.04:LTSlinux-oem-5.17no fix listedUBUNTU-CVE-2022-49707
Ubuntu:22.04:LTSlinux-oem-6.0no fix listedUBUNTU-CVE-2022-49707
Ubuntu:22.04:LTSlinux-oem-6.1no fix listedUBUNTU-CVE-2022-49707
Ubuntu:22.04:LTSlinux-oem-6.5no fix listedUBUNTU-CVE-2022-49707
Ubuntu:22.04:LTSlinux-oracle5.15.0-1018.23UBUNTU-CVE-2022-49707
Ubuntu:22.04:LTSlinux-oracle-6.5no fix listedUBUNTU-CVE-2022-49707
Ubuntu:22.04:LTSlinux-raspi5.15.0-1015.17UBUNTU-CVE-2022-49707
Ubuntu:24.04:LTSlinux-raspi-realtimeno fix listedUBUNTU-CVE-2022-49707
Ubuntu:22.04:LTSlinux-realtimeno fix listedUBUNTU-CVE-2022-49707
Ubuntu:22.04:LTSlinux-riscvno fix listedUBUNTU-CVE-2022-49707
Ubuntu:22.04:LTSlinux-riscv-5.19no fix listedUBUNTU-CVE-2022-49707
Ubuntu:22.04:LTSlinux-riscv-6.5no fix listedUBUNTU-CVE-2022-49707
Ubuntu:22.04:LTSlinux-starfive-5.19no fix listedUBUNTU-CVE-2022-49707
Ubuntu:22.04:LTSlinux-starfive-6.2no fix listedUBUNTU-CVE-2022-49707
Ubuntu:22.04:LTSlinux-starfive-6.5no fix listedUBUNTU-CVE-2022-49707

Affected products (as reported)

VendorProductVersions
Linux Linux 1c6bd7173d66b3dfdefcedb38cabc1fb03997509 – before 0dc2fca8e4f9ac4a40e8424a10163369cca0cc061c6bd7173d66b3dfdefcedb38cabc1fb03997509 – before 7c921328ac760bba780bdace41f4cd045f7f14051c6bd7173d66b3dfdefcedb38cabc1fb03997509 – before b9747263b13e5290ac4d63bec47e38f701303cad1c6bd7173d66b3dfdefcedb38cabc1fb03997509 – before fba54289176702a7caac0b64738406775817f4511c6bd7173d66b3dfdefcedb38cabc1fb03997509 – before bfd004a1d3a062aac300523d406ac1f3e5f1a82c1c6bd7173d66b3dfdefcedb38cabc1fb03997509 – before 33b1bba31f4c784d33d2c2517964bdccdc9204cd1c6bd7173d66b3dfdefcedb38cabc1fb03997509 – before af75c481a2e45e70f62f5942c93695e95bf7bd211c6bd7173d66b3dfdefcedb38cabc1fb03997509 – before b55c3cd102a6f48b90e61c44f7f3dda8c290c694
Linux Linux 3.7

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

References