CVE-2026-98170smb: client: fix OOB struct field reads in move_smb2_ea_to_cifs()

Official description

In the Linux kernel, the following vulnerability has been resolved: smb: client: fix OOB struct field reads in move_smb2_ea_to_cifs() In move_smb2_ea_to_cifs(), the while (src_size > 0) loop condition is insufficient. It allows iteration to continue even if the remaining src_size is too small to contain a complete smb2_ea_info structure. Consequently, reads of ea_name_length and ea_value_length can occur out-of-bounds. Fix this by ensuring src_size >= sizeof(*src) before attempting to read any structure fields. Additionally, reject any next_entry_offset that is smaller than sizeof(*src) or that would advance the pointer beyond the available buffer. Note that for calls where the server returns a malformed EA list, the error returned to userspace changes from -ENODATA (getxattr) or -ERANGE (listxattr) to -EIO. This correctly signals a server protocol error rather than misleadingly indicating "attribute not present" or "output buffer too small".

Affected packages & fixed versions

Affected products (as reported)

References

• https://git.kernel.org/stable/c/22886b1b7464613373c9a7d0af2ace029c50cd97
• https://git.kernel.org/stable/c/9d707a278c100c26d10fbbbd03988778ffc992ce
• https://git.kernel.org/stable/c/90a13af4c9b1369327395bababfe87c75599cc19
• https://git.kernel.org/stable/c/61812323c037a94e2e7f0db7ee740c34b126bffe
• https://git.kernel.org/stable/c/d3546cecbf81d98bf3b472d341f981eb48c04f47
• https://git.kernel.org/stable/c/34a3942e787b9c59758115bd65fe1ec89d68c7a4
• https://git.kernel.org/stable/c/13efcd37a9b3d6ffa1579c3dda3e29c893ed9bca
• https://git.kernel.org/stable/c/eeb5ef6083e1cefa2ef75041b5597ff228b8d7bb