Import Source
https://github.com/microsoft/AzureLinuxVulnerabilityData/blob/main/osv/AZL-88815.json
JSON Data
https://api.test.osv.dev/v1/vulns/AZL-88815
Upstream
Published
2026-05-28T10:16:31Z
Modified
2026-08-28T17:47:35Z
Summary
CVE-2026-46159 affecting package kernel for versions less than 6.6.141.1-1
Details

In the Linux kernel, the following vulnerability has been resolved:

btrfs: fix btrfs_ioctl_space_info() slot_count TOCTOU which can lead to info-leak

btrfs_ioctl_space_info() has a TOCTOU race between two passes over the block group RAID type lists. The first pass counts entries to determine the allocation size, then the second pass fills the buffer. The groups_sem rwlock is released between passes, allowing concurrent block group removal to reduce the entry count.

When the second pass fills fewer entries than the first pass counted, copy_to_user() copies the full alloc_size bytes including trailing uninitialized kmalloc bytes to userspace.

Fix by copying only total_spaces entries (the actually-filled count from the second pass) instead of alloc_size bytes, and switch to kzalloc so any future copy size mismatch cannot leak heap data.

References

Affected packages

Azure Linux:3 / kernel

Package

Name
kernel
Purl
pkg:rpm/azure-linux/kernel

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0 Unknown introduced version / All previous versions are affected
Fixed
6.6.141.1-1

Database specific

source
"https://github.com/microsoft/AzureLinuxVulnerabilityData/blob/main/osv/AZL-88815.json"