CVE-2026-98169

Summary

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

smb: client: fix potential OOB read in smb3_enum_snapshots()

If snapshot_array_size is smaller than GMT_TOKEN_SIZE, smb3_enum_snapshots() sets ret_data_len to sizeof(struct smb_snapshot_array) without verifying the actual length of the server's reply.

Because SMB2_ioctl() places no lower bound on the server-supplied OutputCount and allocates retbuf to exactly that length, a short reply results in ret_data_len exceeding the size of retbuf. The subsequent copy_to_user() then reads past the end of retbuf, leaking adjacent slab memory to userspace. The subsequent clamp check is ineffective as it only reduces ret_data_len.

Fix this by rejecting replies shorter than sizeof(struct smb_snapshot_array) with -EIO. Note that the bound is set to the 12-byte struct size rather than the 16-byte MIN_SNAPSHOT_ARRAY_SIZE defined in MS-SMB2 3.3.5.15.1, because 12 bytes is exactly what copy_to_user() attempts to read.

Affected Software

VendorProductVersion RangeStatus
LinuxLinuxe02789a53d71334b067ad72eee5d4e88a0158083 < 15a221c734b9d044ab769e7e3606b2cab96fb65aaffected
LinuxLinuxe02789a53d71334b067ad72eee5d4e88a0158083 < 74995ee8305a7c4d76ee70d6acd996a75eda3c03affected
LinuxLinuxe02789a53d71334b067ad72eee5d4e88a0158083 < 210f0f1f67817e7d2348b86b5115a9b85ef5c98baffected
LinuxLinuxe02789a53d71334b067ad72eee5d4e88a0158083 < 1cdf0d304d820fb13bf0faf532c3459600f9ea43affected
LinuxLinuxe02789a53d71334b067ad72eee5d4e88a0158083 < dbe452a905dfe2804647530a9ff3d7e3826ed04daffected
LinuxLinuxe02789a53d71334b067ad72eee5d4e88a0158083 < 4775c3b7a597907e0b97556c7986fda238a377aeaffected
LinuxLinuxa94703ff8e3647f8a9a3a92a468450299a7b77e9affected
LinuxLinux82a856f527334ffd69aae26e7dd9e03b19c4a520affected
LinuxLinux25b981bfe192fd208ba04c81f4aa30ffb5141660affected
LinuxLinux4.9.125 < 4.10affected
LinuxLinux4.14.68 < 4.15affected
LinuxLinux4.18.6 < 4.19affected
LinuxLinux4.19affected
LinuxLinux0 < 4.19unaffected
LinuxLinux6.1.189 <= 6.1.*unaffected
LinuxLinux6.6.158 <= 6.6.*unaffected
LinuxLinux6.12.112 <= 6.12.*unaffected
LinuxLinux6.18.54 <= 6.18.*unaffected
LinuxLinux7.2.8 <= 7.2.*unaffected
LinuxLinux7.3-rc4 <= *unaffected

Weaknesses

References