cbcvebase.
CVE-2024-35807
published 2024-05-17

CVE-2024-35807: 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…

PriorityP422medium5.5CVSS 3.1
AVLACLPRLUINSUCNINAH
EPSS
0.27%
18.9th percentile
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

Affected

27 ranges· showing 25
VendorProductVersion rangeFixed in
debiandebian_linux
debianlinux< linux 6.1.85-1 (bookworm)linux 6.1.85-1 (bookworm)
linuxlinux
linuxlinux>= 01f795f9e0d67adeccc61a8b20c28acb45fa5fd8 < 75cc31c2e7193b69f5d25650bda5bb42ed92f8a175cc31c2e7193b69f5d25650bda5bb42ed92f8a1
linuxlinux>= 01f795f9e0d67adeccc61a8b20c28acb45fa5fd8 < ee4e9c1976147a850f6085a13fca95bcaa00d84cee4e9c1976147a850f6085a13fca95bcaa00d84c
linuxlinux>= 01f795f9e0d67adeccc61a8b20c28acb45fa5fd8 < e8e8b197317228b5089ed9e7802dadf3ccaa027ae8e8b197317228b5089ed9e7802dadf3ccaa027a
linuxlinux>= 01f795f9e0d67adeccc61a8b20c28acb45fa5fd8 < 239c669edb2bffa1aa2612519b1d438ab35d6be6239c669edb2bffa1aa2612519b1d438ab35d6be6
linuxlinux>= 01f795f9e0d67adeccc61a8b20c28acb45fa5fd8 < fb1088d51bbaa0faec5a55d4f5818a9ab79e24dffb1088d51bbaa0faec5a55d4f5818a9ab79e24df
linuxlinux>= 01f795f9e0d67adeccc61a8b20c28acb45fa5fd8 < 37b6a3ba793bbbae057f5b991970ebcc52cb3db537b6a3ba793bbbae057f5b991970ebcc52cb3db5
linuxlinux>= 01f795f9e0d67adeccc61a8b20c28acb45fa5fd8 < b461910af8ba3bed80f48c2bf852686d05c6fc5cb461910af8ba3bed80f48c2bf852686d05c6fc5c
linuxlinux>= 01f795f9e0d67adeccc61a8b20c28acb45fa5fd8 < 722d2c01b8b108f8283d1b7222209d5b2a5aa7bd722d2c01b8b108f8283d1b7222209d5b2a5aa7bd
linuxlinux>= 01f795f9e0d67adeccc61a8b20c28acb45fa5fd8 < a6b3bfe176e8a5b05ec4447404e412c2a3fc92cca6b3bfe176e8a5b05ec4447404e412c2a3fc92cc
linuxlinux_kernel>= 0 < 5.10.216-15.10.216-1
linuxlinux_kernel>= 0 < 6.1.85-16.1.85-1
linuxlinux_kernel>= 0 < 6.7.12-16.7.12-1
linuxlinux_kernel>= 0 < 6.7.12-16.7.12-1
linuxlinux_kernel>= 0 < 5.4.0-189.2095.4.0-189.209
linuxlinux_kernel>= 0 < 5.15.0-116.1265.15.0-116.126
linuxlinux_kernel>= 0 < 6.8.0-35.356.8.0-35.35
linuxlinux_kernel>= 3.7 < 4.19.3124.19.312
linuxlinux_kernel>= 4.20 < 5.4.2745.4.274
linuxlinux_kernel>= 5.11 < 5.15.1545.15.154
linuxlinux_kernel>= 5.16 < 6.1.846.1.84
linuxlinux_kernel>= 5.5 < 5.10.2155.10.215
linuxlinux_kernel>= 6.2 < 6.6.246.6.24

CVSS provenance

nvdv3.15.5MEDIUMCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
osv7.0HIGH
vendor_ubuntu7.0HIGH
vendor_debian5.5MEDIUM
vendor_redhat5.5MEDIUM
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