{"id":"CVE-2026-46159","title":"In the Linux kernel, the following vulnerability has been resolved:\n\nbtrfs: fix btrfs_ioctl_space_info() slot_count TOCTOU which can lead to info-leak\n\nbtrfs_ioctl_space_info() has a TOCTOU race between two passes over the\nblock group RA…","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nbtrfs: fix btrfs_ioctl_space_info() slot_count TOCTOU which can lead to info-leak\n\nbtrfs_ioctl_space_info() has a TOCTOU race between two passes over the\nblock group RA…","severity":"medium","cvss":4.7,"cvssVector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H","cwe":["CWE-367"],"vendor":"linux","product":"linux_kernel","affected":["linux_kernel >= 2.6.34.1, < 6.6.140","linux_kernel >= 6.7, < 6.12.90","linux_kernel >= 6.13, < 6.18.32","linux_kernel >= 6.19, < 7.0.7","linux_kernel = 2.6.34"],"patched":["linux_kernel 7.0.7"],"published":"2026-05-28","updated":"2026-10-15","sourceUpdated":"2026-10-15T02:19:47.090","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-46159","references":[{"url":"https://git.kernel.org/stable/c/4fdc6ee0802121d9cd96b8d085e589f51e5a4ec3","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/5d12e0ab009ade48c1bff9324fd9bea2c773d088","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/973e57c726c1f8e77259d1c8e519519f1e9aea77","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/d09d67d5de577cedae3de9497dff217e0ac8b641","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/d69a4a6813fdba7c4cc3695a7e843842b240790d","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/d8224b1be6627c6c3b204bfb264508d27c65ac44","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/f407aad350bdea4db300c47433573b7a41630d33","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/f5ee467b56764964027c361641f64953fc0f8f9a","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://cert-portal.siemens.com/productcert/html/ssa-784472.html","label":"0b142b55-0307-4c5a-b3c9-f314f3fb7c5e"}],"tags":["nvd","cve.org"],"epss":0.00093,"epssPercentile":0.00539,"ingestedAt":"2026-10-15T03:30:12.892Z","slug":"CVE-2026-46159","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nbtrfs: fix btrfs_ioctl_space_info() slot_count TOCTOU which can lead to info-leak\n\nbtrfs_ioctl_space_info() has a TOCTOU race between two passes over the\nblock group RAID type lists. The first pass counts entries to determine\nthe allocation size, then the second pass fills the buffer. The\ngroups_sem rwlock is released between passes, allowing concurrent block\ngroup removal to reduce the entry count.\n\nWhen the second pass fills fewer entries than the first pass counted,\ncopy_to_user() copies the full alloc_size bytes including trailing\nuninitialized kmalloc bytes to userspace.\n\nFix by copying only total_spaces entries (the actually-filled count from\nthe second pass) instead of alloc_size bytes, and switch to kzalloc so\nany future copy size mismatch cannot leak heap data.\n\n## Affected\n\n- `linux_kernel >= 2.6.34.1, < 6.6.140`\n- `linux_kernel >= 6.7, < 6.12.90`\n- `linux_kernel >= 6.13, < 6.18.32`\n- `linux_kernel >= 6.19, < 7.0.7`\n- `linux_kernel = 2.6.34`\n\n## Remediation\n\nUpgrade past the affected range:\n\n- `linux_kernel 7.0.7`","depth":"sunlit","depthScore":26,"depthScoreParts":{"impact":25.9,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}