linux/net/xdp
Magnus Karlsson f654fae47e xsk: Fix broken Tx ring validation
Fix broken Tx ring validation for AF_XDP. The commit under the Fixes
tag, fixed an off-by-one error in the validation but introduced
another error. Descriptors are now let through even if they straddle a
chunk boundary which they are not allowed to do in aligned mode. Worse
is that they are let through even if they straddle the end of the umem
itself, tricking the kernel to read data outside the allowed umem
region which might or might not be mapped at all.

Fix this by reintroducing the old code, but subtract the length by one
to fix the off-by-one error that the original patch was
addressing. The test chunk != chunk_end makes sure packets do not
straddle chunk boundraries. Note that packets of zero length are
allowed in the interface, therefore the test if the length is
non-zero.

Fixes: ac31565c21 ("xsk: Fix for xp_aligned_validate_desc() when len == chunk_size")
Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Acked-by: Björn Töpel <bjorn@kernel.org>
Link: https://lore.kernel.org/bpf/20210618075805.14412-1-magnus.karlsson@gmail.com
2021-06-18 16:59:20 +02:00
..
Kconfig treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
Makefile xsk: Introduce AF_XDP buffer allocation API 2020-05-21 17:31:26 -07:00
xdp_umem.c xsk: Fix umem cleanup bug at socket destruct 2020-11-20 15:52:39 +01:00
xdp_umem.h xsk: Fix umem cleanup bug at socket destruct 2020-11-20 15:52:39 +01:00
xsk.c xsk: Align XDP socket batch size with DPDK 2021-04-23 09:50:35 +02:00
xsk.h xdp: Remove the functions xsk_map_inc and xsk_map_put 2020-11-27 23:00:51 +01:00
xsk_buff_pool.c xsk: Fold xp_assign_dev and __xp_assign_dev 2021-01-25 23:56:33 +01:00
xsk_diag.c xsk: Fix possible segfault in xsk umem diagnostics 2020-09-02 16:49:40 +02:00
xsk_queue.c xsk: Remove MEM_TYPE_ZERO_COPY and corresponding code 2020-05-21 17:31:27 -07:00
xsk_queue.h xsk: Fix broken Tx ring validation 2021-06-18 16:59:20 +02:00
xskmap.c bpf, xdp: Restructure redirect actions 2021-03-10 01:06:34 +01:00