--- id: CVE-2024-35807 title: |- In the Linux kernel, the following vulnerability has been resolved: ext4: fix corruption during on-line resize We observed a corruption during on-line resize of a file system that is larger than 16 TiB with 4k block size summary: |- In the Linux kernel, the following vulnerability has been resolved: ext4: fix corruption during on-line resize We observed a corruption during on-line resize of a file system that is larger than 16 TiB with 4k block size. With having m… severity: medium cvss: 5.5 cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H' vendor: linux product: linux_kernel affected: - 'linux_kernel >= 3.7, < 4.19.312' - 'linux_kernel >= 4.20, < 5.4.274' - 'linux_kernel >= 5.5, < 5.10.215' - 'linux_kernel >= 5.11, < 5.15.154' - 'linux_kernel >= 5.16, < 6.1.84' - 'linux_kernel >= 6.2, < 6.6.24' - 'linux_kernel >= 6.7, < 6.7.12' - 'linux_kernel >= 6.8, < 6.8.3' - debian_linux = 10.0 patched: - linux_kernel 6.8.3 published: '2024-05-17' updated: '2026-10-15' sourceUpdated: '2026-10-15T01:17:46.740' source: NVD sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2024-35807' references: - url: 'https://git.kernel.org/stable/c/239c669edb2bffa1aa2612519b1d438ab35d6be6' label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 - url: 'https://git.kernel.org/stable/c/37b6a3ba793bbbae057f5b991970ebcc52cb3db5' label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 - url: 'https://git.kernel.org/stable/c/722d2c01b8b108f8283d1b7222209d5b2a5aa7bd' label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 - url: 'https://git.kernel.org/stable/c/75cc31c2e7193b69f5d25650bda5bb42ed92f8a1' label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 - url: 'https://git.kernel.org/stable/c/a6b3bfe176e8a5b05ec4447404e412c2a3fc92cc' label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 - url: 'https://git.kernel.org/stable/c/b461910af8ba3bed80f48c2bf852686d05c6fc5c' label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 - url: 'https://git.kernel.org/stable/c/e8e8b197317228b5089ed9e7802dadf3ccaa027a' label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 - url: 'https://git.kernel.org/stable/c/ee4e9c1976147a850f6085a13fca95bcaa00d84c' label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 - url: 'https://git.kernel.org/stable/c/fb1088d51bbaa0faec5a55d4f5818a9ab79e24df' label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 - url: 'https://git.kernel.org/stable/c/239c669edb2bffa1aa2612519b1d438ab35d6be6' label: af854a3a-2127-422b-91ae-364da2661108 - url: 'https://git.kernel.org/stable/c/37b6a3ba793bbbae057f5b991970ebcc52cb3db5' label: af854a3a-2127-422b-91ae-364da2661108 - url: 'https://git.kernel.org/stable/c/722d2c01b8b108f8283d1b7222209d5b2a5aa7bd' label: af854a3a-2127-422b-91ae-364da2661108 - url: 'https://git.kernel.org/stable/c/75cc31c2e7193b69f5d25650bda5bb42ed92f8a1' label: af854a3a-2127-422b-91ae-364da2661108 - url: 'https://git.kernel.org/stable/c/a6b3bfe176e8a5b05ec4447404e412c2a3fc92cc' label: af854a3a-2127-422b-91ae-364da2661108 - url: 'https://git.kernel.org/stable/c/b461910af8ba3bed80f48c2bf852686d05c6fc5c' label: af854a3a-2127-422b-91ae-364da2661108 - url: 'https://git.kernel.org/stable/c/e8e8b197317228b5089ed9e7802dadf3ccaa027a' label: af854a3a-2127-422b-91ae-364da2661108 - url: 'https://git.kernel.org/stable/c/ee4e9c1976147a850f6085a13fca95bcaa00d84c' label: af854a3a-2127-422b-91ae-364da2661108 - url: 'https://git.kernel.org/stable/c/fb1088d51bbaa0faec5a55d4f5818a9ab79e24df' label: af854a3a-2127-422b-91ae-364da2661108 - url: 'https://lists.debian.org/debian-lts-announce/2024/06/msg00017.html' label: af854a3a-2127-422b-91ae-364da2661108 - url: 'https://lists.debian.org/debian-lts-announce/2024/06/msg00020.html' label: af854a3a-2127-422b-91ae-364da2661108 - url: 'https://cert-portal.siemens.com/productcert/html/ssa-265688.html' label: 0b142b55-0307-4c5a-b3c9-f314f3fb7c5e - url: 'https://cert-portal.siemens.com/productcert/html/ssa-398330.html' label: 0b142b55-0307-4c5a-b3c9-f314f3fb7c5e tags: - nvd - cve.org epss: 0.00271 epssPercentile: 0.19215 ingestedAt: '2026-10-15T03:30:12.679Z' ssvc: exploitation: none automatable: 'no' technicalImpact: partial timestamp: '2024-06-12T15:25:51.499528Z' --- ## Overview In the Linux kernel, the following vulnerability has been resolved: ext4: fix corruption during on-line resize We observed a corruption during on-line resize of a file system that is larger than 16 TiB with 4k block size. With having more then 2^32 blocks resize_inode is turned off by default by mke2fs. The issue can be reproduced on a smaller file system for convenience by explicitly turning off resize_inode. An on-line resize across an 8 GiB boundary (the size of a meta block group in this setup) then leads to a corruption: dev=/dev/ # should be >= 16 GiB mkdir -p /corruption /sbin/mke2fs -t ext4 -b 4096 -O ^resize_inode $dev $((2 * 2**21 - 2**15)) mount -t ext4 $dev /corruption dd if=/dev/zero bs=4096 of=/corruption/test count=$((2*2**21 - 4*2**15)) sha1sum /corruption/test # 79d2658b39dcfd77274e435b0934028adafaab11 /corruption/test /sbin/resize2fs $dev $((2*2**21)) # drop page cache to force reload the block from disk echo 1 > /proc/sys/vm/drop_caches sha1sum /corruption/test # 3c2abc63cbf1a94c9e6977e0fbd72cd832c4d5c3 /corruption/test 2^21 = 2^15*2^6 equals 8 GiB whereof 2^15 is the number of blocks per block group and 2^6 are the number of block groups that make a meta block group. The last checksum might be different depending on how the file is laid out across the physical blocks. The actual corruption occurs at physical block 63*2^15 = 2064384 which would be the location of the backup of the meta block group's block descriptor. During the on-line resize the file system will be converted to meta_bg starting at s_first_meta_bg which is 2 in the example - meaning all block groups after 16 GiB. However, in ext4_flex_group_add we might add block groups that are not part of the first meta block group yet. In the reproducer we achieved this by substracting the size of a whole block group from the point where the meta block group would start. This must be considered when updating the backup block group descriptors to follow the non-meta_bg layout. The fix is to add a test whether the group to add is already part of the meta block group or not. ## Affected - `linux_kernel >= 3.7, < 4.19.312` - `linux_kernel >= 4.20, < 5.4.274` - `linux_kernel >= 5.5, < 5.10.215` - `linux_kernel >= 5.11, < 5.15.154` - `linux_kernel >= 5.16, < 6.1.84` - `linux_kernel >= 6.2, < 6.6.24` - `linux_kernel >= 6.7, < 6.7.12` - `linux_kernel >= 6.8, < 6.8.3` - `debian_linux = 10.0` ## Remediation Upgrade past the affected range: - `linux_kernel 6.8.3`