cbcvebase.
CVE-2025-38709
published 2025-09-04

CVE-2025-38709: In the Linux kernel, the following vulnerability has been resolved: loop: Avoid updating block size under exclusive owner Syzbot came up with a reproducer…

PriorityP420medium5.5CVSS 3.1
AVLACLPRLUINSUCNINAH
EPSS
0.14%
3.5th percentile
In the Linux kernel, the following vulnerability has been resolved: loop: Avoid updating block size under exclusive owner Syzbot came up with a reproducer where a loop device block size is changed underneath a mounted filesystem. This causes a mismatch between the block device block size and the block size stored in the superblock causing confusion in various places such as fs/buffer.c. The particular issue triggered by syzbot was a warning in __getblk_slow() due to requested buffer size not matching block device block size. Fix the problem by getting exclusive hold of the loop device to change its block size. This fails if somebody (such as filesystem) has already an exclusive ownership of the block device and thus prevents modifying the loop device under some exclusive owner which doesn't expect it.

Affected

28 ranges· showing 25
VendorProductVersion rangeFixed in
debianlinux< linux 6.16.3-1 (forky)linux 6.16.3-1 (forky)
linuxlinux
linuxlinux>= 89e4fdecb51cf5535867026274bc97de9480ade5 < 457d2c5e112fd08dc1039b1ae39a83ec1782360d457d2c5e112fd08dc1039b1ae39a83ec1782360d
linuxlinux>= 89e4fdecb51cf5535867026274bc97de9480ade5 < 139a000d20f2f38ce34296feddd641d730fe1c08139a000d20f2f38ce34296feddd641d730fe1c08
linuxlinux>= 89e4fdecb51cf5535867026274bc97de9480ade5 < b928438cc87c0bf7ae078e4b7b6e14261e84c5c5b928438cc87c0bf7ae078e4b7b6e14261e84c5c5
linuxlinux>= 89e4fdecb51cf5535867026274bc97de9480ade5 < 5d67b30aefeb7a949040bbb1b4e3b84c5d29a6245d67b30aefeb7a949040bbb1b4e3b84c5d29a624
linuxlinux>= 89e4fdecb51cf5535867026274bc97de9480ade5 < 7e49538288e523427beedd26993d446afef1a6fb7e49538288e523427beedd26993d446afef1a6fb
linuxlinux_kernel< 6.6.1096.6.109
linuxlinux_kernel>= 0 < 6.12.43-16.12.43-1
linuxlinux_kernel>= 0 < 6.16.3-16.16.3-1
linuxlinux_kernel>= 0 < 6.8.0-106.1066.8.0-106.106
linuxlinux_kernel>= 6.13 < 6.15.116.15.11
linuxlinux_kernel>= 6.16 < 6.16.26.16.2
linuxlinux_kernel>= 6.7 < 6.12.436.12.43
msrcazl3_httpd_2.4.58-4_on_azure_linux_3.0
msrcazl3_httpd_2.4.61-1_on_azure_linux_3.0
msrcazl3_kernel_6.6.96.2-1_on_azure_linux_3.0
msrcazl3_kernel_6.6.96.2-2_on_azure_linux_3.0
msrcazure_linux_3.0_arm
msrcazure_linux_3.0_x64
msrccbl2_httpd_2.4.58-1_on_cbl_mariner_2.0
msrccbl2_httpd_2.4.59-1_on_cbl_mariner_2.0
msrccbl2_kernel_5.15.186.1-1_on_cbl_mariner_2.0
msrccbl2_kernel_5.15.200.1-1_on_cbl_mariner_2.0
msrccbl2_kernel_5.15.202.1-1_on_cbl_mariner_2.0

CVSS provenance

nvdv3.15.5MEDIUMCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
osv5.5MEDIUM
vendor_ubuntu7.8HIGH
vendor_msrc7.3HIGH
vendor_debian5.5MEDIUM
vendor_redhat5.5MEDIUM
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