Andrii Nakryiko dfeb376dd4 bpf: Prevent mmap()'ing read-only maps as writable ... As discussed in [0], it's dangerous to allow mapping BPF map, that's meant to be frozen and is read-only on BPF program side, because that allows user-space to actually store a writable view to the page even after it is frozen. This is exacerbated by BPF verifier making a strong assumption that contents of such frozen map will remain unchanged. To prevent this, disallow mapping BPF_F_RDONLY_PROG mmap()'able BPF maps as writable, ever. [0] https://lore.kernel.org/bpf/CAEf4BzYGWYhXdp6BJ7_=9OQPJxQpgug080MMjdSB72i9R+5c6g@mail.gmail.com/ Fixes: fc9702273e ("bpf: Add mmap() support for BPF_MAP_TYPE_ARRAY") Suggested-by: Jann Horn <jannh@google.com> Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Reviewed-by: Jann Horn <jannh@google.com> Link: https://lore.kernel.org/bpf/20200519053824.1089415-1-andriin@fb.com		2020-05-20 20:21:53 -07:00
..
fault-injection	docs: fault-injection: convert docs to ReST and rename to *.rst	2019-06-14 14:21:07 -06:00
ktest	ktest: Fix typos in ktest.pl	2020-03-09 16:15:27 -04:00
kunit	SPDX patches for 5.7-rc1.	2020-04-03 13:12:26 -07:00
nvdimm	tools/test/nvdimm: Fix out of tree build	2020-03-31 14:12:32 -07:00
radix-tree	SPDX patches for 5.7-rc1.	2020-04-03 13:12:26 -07:00
scatterlist	treewide: Add SPDX license identifier - Makefile/Kconfig	2019-05-21 10:50:46 +02:00
selftests	bpf: Prevent mmap()'ing read-only maps as writable	2020-05-20 20:21:53 -07:00
vsock	SPDX patches for 5.7-rc1.	2020-04-03 13:12:26 -07:00