Description
In the Linux kernel, the following vulnerability has been resolved: smb: client: fix off-by-8 bounds check in check_wsl_eas() The bounds check uses (u8 *)ea + nlen + 1 + vlen as the end of the EA name and value, but ea_data sits at offset sizeof(struct smb2_file_full_ea_info) = 8 from ea, not at offset 0. The strncmp() later reads ea->ea_data[0..nlen-1] and the value bytes follow at ea_data[nlen+1..nlen+vlen], so the actual end is ea->ea_data + nlen + 1 + vlen. Isn't pointer math fun? The earlier check (u8 *)ea > end - sizeof(*ea) only guarantees the 8-byte header is in bounds, but since the last EA is placed within 8 bytes of the end of the response, the name and value bytes are read past the end of iov. Fix this mess all up by using ea->ea_data as the base for the bounds check. An "untrusted" server can use this to leak up to 8 bytes of kernel heap into the EA name comparison and influence which WSL xattr the data is interpreted as.
Product status
ea41367b2a602f602ea6594fc4a310520dcc64f4 (git) before 5cc0574c84aa73946ade587c41e81757b8b01cb5
ea41367b2a602f602ea6594fc4a310520dcc64f4 (git) before b2b76d09a64c538c57006180103fc1841e8cfa66
ea41367b2a602f602ea6594fc4a310520dcc64f4 (git) before ba3ad159aa61810bbe0acaf39578b1ebfb6f1a18
ea41367b2a602f602ea6594fc4a310520dcc64f4 (git) before a893f1757d9a4009e4a8d7ceb2312142fe29cea4
7449d736bbbd160c76b01b8fcdf72f58a8757d4b (git)
6.9
Any version before 6.9
6.12.83 (semver)
6.18.24 (semver)
6.19.14 (semver)
7.0.1 (semver)
References
git.kernel.org/...c/5cc0574c84aa73946ade587c41e81757b8b01cb5
git.kernel.org/...c/b2b76d09a64c538c57006180103fc1841e8cfa66
git.kernel.org/...c/ba3ad159aa61810bbe0acaf39578b1ebfb6f1a18
git.kernel.org/...c/a893f1757d9a4009e4a8d7ceb2312142fe29cea4