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alistair23-linux/net/xdp
Björn Töpel b16a87d0ae xsk: Add overflow check for u64 division, stored into u32
The npgs member of struct xdp_umem is an u32 entity, and stores the
number of pages the UMEM consumes. The calculation of npgs

  npgs = size / PAGE_SIZE

can overflow.

To avoid overflow scenarios, the division is now first stored in a
u64, and the result is verified to fit into 32b.

An alternative would be storing the npgs as a u64, however, this
wastes memory and is an unrealisticly large packet area.

Fixes: c0c77d8fb7 ("xsk: add user memory registration support sockopt")
Reported-by: "Minh Bùi Quang" <minhquangbui99@gmail.com>
Signed-off-by: Björn Töpel <bjorn.topel@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Jonathan Lemon <jonathan.lemon@gmail.com>
Link: https://lore.kernel.org/bpf/CACtPs=GGvV-_Yj6rbpzTVnopgi5nhMoCcTkSkYrJHGQHJWFZMQ@mail.gmail.com/
Link: https://lore.kernel.org/bpf/20200525080400.13195-1-bjorn.topel@gmail.com
2020-05-26 00:06:00 +02:00
..
Kconfig treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
Makefile treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
xdp_umem.c xsk: Add overflow check for u64 division, stored into u32 2020-05-26 00:06:00 +02:00
xdp_umem.h xdp: fix hang while unregistering device bound to xdp socket 2019-07-03 15:10:55 +02:00
xsk.c xsk: Fix out of boundary write in __xsk_rcv_memcpy 2020-04-06 21:48:05 +02:00
xsk.h xsk: add support for need_wakeup flag in AF_XDP rings 2019-08-17 23:07:32 +02:00
xsk_diag.c xsk: lock the control mutex in sock_diag interface 2019-09-05 14:11:52 +02:00
xsk_queue.c xsk: Use struct_size() helper 2019-12-20 16:00:09 -08:00
xsk_queue.h xdp: Replace zero-length array with flexible-array member 2020-02-28 12:08:37 -08:00