`virtio_transport_stream_do_peek`, when calculating the number of bytes to copy, didn't consider the `offset`, caused by partial reads that happened before. This might cause out-of-bounds read that lead to an EFAULT. More details in the commits.
Commit 1 introduces the fix Commit 2 introduces some preliminary work for adding a test Commit 3 introduces a test that checks for this bug to avoid future regressions. Signed-off-by: Luigi Leonardi <[email protected]> --- Changes in v2: - Addressed reviewers comment - Test now uses the recv_buf utils. - Removed unnecessary barrier - Checkpatch warnings. - Added new commit that allows to use recv_buf with MSG_PEEK - Picked up RoBs - Link to v1: https://lore.kernel.org/r/[email protected] --- Luigi Leonardi (3): vsock/virtio: fix MSG_PEEK ignoring skb offset when calculating bytes to copy vsock/test: handle MSG_PEEK in `recv_buf` vsock/test: add MSG_PEEK after partial recv test net/vmw_vsock/virtio_transport_common.c | 5 ++- tools/testing/vsock/util.c | 8 +++++ tools/testing/vsock/vsock_test.c | 56 ++++++++++++++++++++++++++------- 3 files changed, 54 insertions(+), 15 deletions(-) --- base-commit: bfe62a454542cfad3379f6ef5680b125f41e20f4 change-id: 20260401-fix_peek-6837b83469e3 Best regards, -- Luigi Leonardi <[email protected]>
