CVE-2025-38172 Information

Jul 04, 2025 cve

Description

In the Linux kernel the following vulnerability has been resolved:

erofs: avoid using multiple devices with different type

For multiple devices both primary and extra devices should be the same type. erofs_init_device has already guaranteed that if the primary is a file-backed device extra devices should also be regular files.

However if the primary is a block device while the extra device is a file-backed device erofs_init_device will get an ENOTBLK which is not treated as an error in erofs_fc_get_tree and that leads to an UAF:

erofs_fc_get_tree get_tree_bdev_flags(erofs_fc_fill_super) erofs_read_superblock erofs_init_device // sbi->dif0 is not inited yet // return -ENOTBLK deactivate_locked_super free(sbi) if (err is -ENOTBLK) sbi->dif0.file = filp_open() // sbi UAF

So if -ENOTBLK is hitted in erofs_init_device it means the primary device must be a block device and the extra device is not a block device. The error can be converted to -EINVAL.

Reference

https://git.kernel.org/stable/c/65115472f741ca000d7ea4a5922214f93cd1516e https://git.kernel.org/stable/c/9748f2f54f66743ac77275c34886a9f890e18409 https://git.kernel.org/stable/c/cd04beb9ce2773a16057248bb4fa424068ae3807

CNNVD-202507-259 (Published: 2025-07-03)

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