Re: [PATCH] iov_iter: use kmemdup_array for dup_iter to harden against overflow

[Christian Brauner]

On Mon, 13 Apr 2026 14:06:55 +0800, Wang Haoran wrote:
> While auditing the Linux 7.0-rc2 kernel, I identified a potential security
> vulnerability in the iov_iter framework's memory allocation logic.
> 
> The dup_iter() function, which is exported via EXPORT_SYMBOL, currently
> uses kmemdup() with a raw multiplication to allocate the duplicate iovec array:
> 
> new->iov = kmemdup(from->iov, nr_segs * sizeof(struct iovec), gfp);
> 
> [...]

Applied to the vfs-7.2.misc branch of the vfs/vfs.git tree.
Patches in the vfs-7.2.misc branch should appear in linux-next soon.

Please report any outstanding bugs that were missed during review in a
new review to the original patch series allowing us to drop it.

It's encouraged to provide Acked-bys and Reviewed-bys even though the
patch has now been applied. If possible patch trailers will be updated.

Note that commit hashes shown below are subject to change due to rebase,
trailer updates or similar. If in doubt, please check the listed branch.

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs.git
branch: vfs-7.2.misc

[1/1] iov_iter: use kmemdup_array for dup_iter to harden against overflow
      https://git.kernel.org/vfs/vfs/c/ea5efcc5c589