Claude review: dma-buf: set SB_I_NOEXEC and SB_I_NODEV on the pseudo filesystem

[Claude Code Review Bot <claude-review@example.com>]

Patch Review

**Correctness: Good.** The fix adds `SB_I_NOEXEC` and `SB_I_NODEV` to the superblock's internal flags in `dma_buf_fs_init_context()`. This directly addresses the `VFS_WARN_ON_ONCE` in `path_noexec()` at `fs/exec.c:118-119`:

```c
VFS_WARN_ON_ONCE(IS_ANON_FILE(d_inode(path->dentry)) &&
                 !(path->mnt->mnt_sb->s_iflags & SB_I_NOEXEC));
```

**Placement is correct.** The flags are set on `fc->s_iflags` after the `init_pseudo()` call, which is the same pattern used by `kvm/guest_memfd.c:976-977`:

```c
fc->s_iflags |= SB_I_NOEXEC;
fc->s_iflags |= SB_I_NODEV;
```

**Semantics are correct.** dma-bufs should never be executable (they're GPU memory buffers), and the pseudo filesystem creates no device nodes, so both flags are appropriate.

**Minor style nit (non-blocking):** Some callers (e.g., `ipc/mqueue.c:408`) combine both flags in a single statement: `sb->s_iflags |= SB_I_NOEXEC | SB_I_NODEV;`. Using two separate lines is also fine and arguably more readable — the KVM code follows the same two-line pattern, so this is consistent. No change needed.

**Fixes tag and Cc stable are appropriate.** This is a regression introduced by `1e7ab6f67824` in 6.17, and the fix is trivially backportable.

**Reviewed-by from Christian Brauner** (the VFS maintainer who authored the assertion) is already present, which provides strong confidence in the approach.

No issues found. This patch is ready to merge.

---
Generated by Claude Code Patch Reviewer