Paper/Archive/CVE-2026-89779

CVE-2026-89779

Linux Linux — fs/ntfs3: validate ef->size covers the record's name and value

Description · from the CVE record

In the Linux kernel, the following vulnerability has been resolved: fs/ntfs3: validate ef->size covers the record's name and value When an EA record has a non-zero ef->size, ntfs_read_ea() only checks that the record fits in the remaining buffer (ea_size > bytes), not that ef->size is large enough to hold the record's own name_len + 1 + elength. A crafted image can pass validation with, e.g., ef->size = 24 but elength = 0xffff. ntfs_get_ea() then trusts elength and copies it out of the undersized record, reading past the kmalloc(info->size) allocation and leaking heap memory to userspace via getxattr(): BUG: KASAN: slab-out-of-bounds in ntfs_get_ea (fs/ntfs3/xattr.c:302) Read of size 65535 at addr ffff888100794550 by task exploit __asan_memcpy (mm/kasan/shadow.c:105) ntfs_get_ea (fs/ntfs3/xattr.c:302) ntfs_getxattr (fs/ntfs3/xattr.c:848) __vfs_getxattr (fs/xattr.c:441) vfs_getxattr (fs/xattr.c:474) do_getxattr (fs/xattr.c:800) path_getxattrat (fs/xattr.c:868) do_syscall_64 (arch/x86/entry/syscall_64.c:94) The buggy address is located 80 bytes inside of allocated 84-byte region in cache kmalloc-96 Compute the size the record needs and require ef->size to cover it.

Affected

ProductAffectedFixed inSource
Linux333feb7ba84f69f9b423422417aaac54fd9e7c84 – < b27e68ad818a4ca2cef8f35f97e75d756714c818b27e68ad818a4ca2cef8f35f97e75d756714c818CNA
Linux000a9a72efa4a9df289bab9c9e8ba1639c72e0d6 – < 28a924c7e67e6d71abeb04860b61166fecb027fc28a924c7e67e6d71abeb04860b61166fecb027fcCNA
Linux0e8235d28f3a0e9eda9f02ff67ee566d5f42b66b – < d585ed08308909c7e6fefb4e8a258aeb29b19ff9d585ed08308909c7e6fefb4e8a258aeb29b19ff9CNA
Linux0e8235d28f3a0e9eda9f02ff67ee566d5f42b66b – < 077df8464cf24f8ffc82fb6efec2ae600686e699077df8464cf24f8ffc82fb6efec2ae600686e699CNA
Linux0e8235d28f3a0e9eda9f02ff67ee566d5f42b66b – < aab1880058ac767d3ea9388a9a7221c776c22c44aab1880058ac767d3ea9388a9a7221c776c22c44CNA
Linux0e8235d28f3a0e9eda9f02ff67ee566d5f42b66b – < c8a109c9e23a2c7fd548473dde728b2cb8188146c8a109c9e23a2c7fd548473dde728b2cb8188146CNA
Linux0e8235d28f3a0e9eda9f02ff67ee566d5f42b66b – < c22f91d82cb9a29d22bdffdce6c803467984ad0cc22f91d82cb9a29d22bdffdce6c803467984ad0cCNA
Linux5.15.121 – < 5.15.2215.15.221CNA
Linux6.1.40 – < 6.1.1886.1.188CNA
Linux6.26.1.188CNA

Scores by source

Linux (CNA)9.1CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H

References

refgit.kernel.org/stable/c/b27e68ad818a4ca2cef8f35f97e75d756714c818refgit.kernel.org/stable/c/28a924c7e67e6d71abeb04860b61166fecb027fcrefgit.kernel.org/stable/c/d585ed08308909c7e6fefb4e8a258aeb29b19ff9refgit.kernel.org/stable/c/077df8464cf24f8ffc82fb6efec2ae600686e699refgit.kernel.org/stable/c/aab1880058ac767d3ea9388a9a7221c776c22c44refgit.kernel.org/stable/c/c8a109c9e23a2c7fd548473dde728b2cb8188146refgit.kernel.org/stable/c/c22f91d82cb9a29d22bdffdce6c803467984ad0c