{"id":"CVE-2022-49707","summary":"ext4: add reserved GDT blocks check","details":"In the Linux kernel, the following vulnerability has been resolved:\n\next4: add reserved GDT blocks check\n\nWe capture a NULL pointer issue when resizing a corrupt ext4 image which\nis freshly clear resize_inode feature (not run e2fsck). It could be\nsimply reproduced by following steps. The problem is because of the\nresize_inode feature was cleared, and it will convert the filesystem to\nmeta_bg mode in ext4_resize_fs(), but the es-\u003es_reserved_gdt_blocks was\nnot reduced to zero, so could we mistakenly call reserve_backup_gdb()\nand passing an uninitialized resize_inode to it when adding new group\ndescriptors.\n\n mkfs.ext4 /dev/sda 3G\n tune2fs -O ^resize_inode /dev/sda #forget to run requested e2fsck\n mount /dev/sda /mnt\n resize2fs /dev/sda 8G\n\n ========\n BUG: kernel NULL pointer dereference, address: 0000000000000028\n CPU: 19 PID: 3243 Comm: resize2fs Not tainted 5.18.0-rc7-00001-gfde086c5ebfd #748\n ...\n RIP: 0010:ext4_flex_group_add+0xe08/0x2570\n ...\n Call Trace:\n  \u003cTASK\u003e\n  ext4_resize_fs+0xbec/0x1660\n  __ext4_ioctl+0x1749/0x24e0\n  ext4_ioctl+0x12/0x20\n  __x64_sys_ioctl+0xa6/0x110\n  do_syscall_64+0x3b/0x90\n  entry_SYSCALL_64_after_hwframe+0x44/0xae\n RIP: 0033:0x7f2dd739617b\n ========\n\nThe fix is simple, add a check in ext4_resize_begin() to make sure that\nthe es-\u003es_reserved_gdt_blocks is zero when the resize_inode feature is\ndisabled.","modified":"2026-04-02T08:27:50.908247Z","published":"2025-02-26T02:24:25.441Z","related":["SUSE-SU-2025:1027-1","SUSE-SU-2025:1176-1","SUSE-SU-2025:1183-1","SUSE-SU-2025:1194-1","SUSE-SU-2025:1241-1","SUSE-SU-2025:1263-1","SUSE-SU-2025:1293-1"],"database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2022/49xxx/CVE-2022-49707.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/0dc2fca8e4f9ac4a40e8424a10163369cca0cc06"},{"type":"WEB","url":"https://git.kernel.org/stable/c/33b1bba31f4c784d33d2c2517964bdccdc9204cd"},{"type":"WEB","url":"https://git.kernel.org/stable/c/7c921328ac760bba780bdace41f4cd045f7f1405"},{"type":"WEB","url":"https://git.kernel.org/stable/c/af75c481a2e45e70f62f5942c93695e95bf7bd21"},{"type":"WEB","url":"https://git.kernel.org/stable/c/b55c3cd102a6f48b90e61c44f7f3dda8c290c694"},{"type":"WEB","url":"https://git.kernel.org/stable/c/b9747263b13e5290ac4d63bec47e38f701303cad"},{"type":"WEB","url":"https://git.kernel.org/stable/c/bfd004a1d3a062aac300523d406ac1f3e5f1a82c"},{"type":"WEB","url":"https://git.kernel.org/stable/c/fba54289176702a7caac0b64738406775817f451"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2022/49xxx/CVE-2022-49707.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2022-49707"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"1c6bd7173d66b3dfdefcedb38cabc1fb03997509"},{"fixed":"0dc2fca8e4f9ac4a40e8424a10163369cca0cc06"},{"fixed":"7c921328ac760bba780bdace41f4cd045f7f1405"},{"fixed":"b9747263b13e5290ac4d63bec47e38f701303cad"},{"fixed":"fba54289176702a7caac0b64738406775817f451"},{"fixed":"bfd004a1d3a062aac300523d406ac1f3e5f1a82c"},{"fixed":"33b1bba31f4c784d33d2c2517964bdccdc9204cd"},{"fixed":"af75c481a2e45e70f62f5942c93695e95bf7bd21"},{"fixed":"b55c3cd102a6f48b90e61c44f7f3dda8c290c694"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2022-49707.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H"}]}