ksmbd: replace hardcoded hdr2_len with offsetof() in smb2_calc_max_out_buf_len()

Summary

In the Linux kernel, the following vulnerability has been resolved: ksmbd: replace hardcoded hdr2_len with offsetof() in smb2_calc_max_out_buf_len() After this commit (e2b76ab8b5c9 "ksmbd: add support for read compound"), response buffer management was changed to use dynamic iov array. In the new design, smb2_calc_max_out_buf_len() expects the second argument (hdr2_len) to be the offset of ->Buffer field in the response structure, not a hardcoded magic number. Fix the remaining call sites to use the correct offsetof() value.

Timeline

1. Apr 22, 2026, 1:54 PM UTCCVE published
2. Oct 16, 2026, 3:09 PM UTCCISA SSVC assessment

   Exploitation: none · Automatable: yes · Technical impact: total

3. Oct 19, 2026, 6:45 PM UTCRecord last updated

Affected versions

• Linux Linux

  From f2283680a80571ca82d710bc6ecd8f8beac67d63 · fixed in 70b4c414889492c522b6e4331562360f49be2361; From 9f297df20d93411c0b4ddad7f88ba04a7cd36e77 · fixed in 9a7166f0ef8cbb7bb48dd05e2471d995566003f5; From e2b76ab8b5c9327ab2dae6da05d0752eb2f4771d · fixed in c3a89e3ec1ccf64fa6a34e391e1581ebbcba8683; From e2b76ab8b5c9327ab2dae6da05d0752eb2f4771d · fixed in 6aef1765d6807e0f027cd87f6ac973eb0879a46d; From e2b76ab8b5c9327ab2dae6da05d0752eb2f4771d · fixed in 80824c7e527b70cf9039534e60aff592e8f209d1; From e2b76ab8b5c9327ab2dae6da05d0752eb2f4771d · fixed in 4cb537ae4f37d7d0f617815ed4bed7173fb50861; From e2b76ab8b5c9327ab2dae6da05d0752eb2f4771d · fixed in 0e55f63dd08f09651d39e1b709a91705a8a0ddcb; From 5.15.145 · fixed in 5.15.203; From 6.1.71 · fixed in 6.1.168

• Linux Linux

  6.6

• KernelLinux

  fixed in 5.15.203; From 5.16.0 · fixed in 6.1.168; From 6.2.0 · fixed in 6.6.131; From 6.6.0 · fixed in 6.12.80; From 6.7.0 · fixed in 6.18.21; From 6.13.0 · fixed in 6.19.11

References 7