Stanislav Fomichev d8fe449a9c bpf: Don't return EINVAL from {get,set}sockopt when optlen > PAGE_SIZE ... Attaching to these hooks can break iptables because its optval is usually quite big, or at least bigger than the current PAGE_SIZE limit. David also mentioned some SCTP options can be big (around 256k). For such optvals we expose only the first PAGE_SIZE bytes to the BPF program. BPF program has two options: 1. Set ctx->optlen to 0 to indicate that the BPF's optval should be ignored and the kernel should use original userspace value. 2. Set ctx->optlen to something that's smaller than the PAGE_SIZE. v5: * use ctx->optlen == 0 with trimmed buffer (Alexei Starovoitov) * update the docs accordingly v4: * use temporary buffer to avoid optval == optval_end == NULL; this removes the corner case in the verifier that might assume non-zero PTR_TO_PACKET/PTR_TO_PACKET_END. v3: * don't increase the limit, bypass the argument v2: * proper comments formatting (Jakub Kicinski) Fixes: 0d01da6afc ("bpf: implement getsockopt and setsockopt hooks") Signed-off-by: Stanislav Fomichev <sdf@google.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Cc: David Laight <David.Laight@ACULAB.COM> Link: https://lore.kernel.org/bpf/20200617010416.93086-1-sdf@google.com		2020-06-17 10:54:05 -07:00
..
arraymap.c	Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net	2020-05-15 13:48:59 -07:00
bpf_iter.c	bpf: Enable bpf_iter targets registering ctx argument types	2020-05-13 12:30:50 -07:00
bpf_lru_list.c
bpf_lru_list.h	bpf: Fix a typo "inacitve" -> "inactive"	2020-04-06 21:54:10 +02:00
bpf_lsm.c	bpf: Use tracing helpers for lsm programs	2020-06-01 15:08:04 -07:00
bpf_struct_ops_types.h
bpf_struct_ops.c	bpf: Implement CAP_BPF	2020-05-15 17:29:41 +02:00
btf.c	bpf: Enable bpf_iter targets registering ctx argument types	2020-05-13 12:30:50 -07:00
cgroup.c	bpf: Don't return EINVAL from {get,set}sockopt when optlen > PAGE_SIZE	2020-06-17 10:54:05 -07:00
core.c	Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next	2020-06-03 16:27:18 -07:00
cpumap.c	xdp: Rename convert_to_xdp_frame in xdp_convert_buff_to_frame	2020-06-01 15:02:53 -07:00
devmap.c	devmap: Use bpf_map_area_alloc() for allocating hash buckets	2020-06-17 10:01:19 -07:00
disasm.c
disasm.h
dispatcher.c
hashtab.c	bpf: Implement CAP_BPF	2020-05-15 17:29:41 +02:00
helpers.c	bpf: Implement BPF ring buffer and verifier support for it	2020-06-01 14:38:22 -07:00
inode.c	bpf: Create file bpf iterator	2020-05-09 17:05:26 -07:00
local_storage.c
lpm_trie.c	bpf: Implement CAP_BPF	2020-05-15 17:29:41 +02:00
Makefile	flow_dissector: Move out netns_bpf prog callbacks	2020-06-01 15:21:02 -07:00
map_in_map.c	bpf: Implement CAP_BPF	2020-05-15 17:29:41 +02:00
map_in_map.h
map_iter.c	bpf: Enable bpf_iter targets registering ctx argument types	2020-05-13 12:30:50 -07:00
net_namespace.c	bpf: Add link-based BPF program attachment to network namespace	2020-06-01 15:21:03 -07:00
offload.c
percpu_freelist.c
percpu_freelist.h
queue_stack_maps.c	bpf: Implement CAP_BPF	2020-05-15 17:29:41 +02:00
reuseport_array.c	bpf: Implement CAP_BPF	2020-05-15 17:29:41 +02:00
ringbuf.c	bpf: Implement BPF ring buffer and verifier support for it	2020-06-01 14:38:22 -07:00
stackmap.c	mmap locking API: add mmap_read_trylock_non_owner()	2020-06-09 09:39:14 -07:00
syscall.c	Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net	2020-06-13 16:27:13 -07:00
sysfs_btf.c
task_iter.c	bpf: Fix bpf_iter's task iterator logic	2020-05-14 18:37:32 -07:00
tnum.c	bpf: Verifier, do explicit ALU32 bounds tracking	2020-03-30 14:59:53 -07:00
trampoline.c
verifier.c	bpf: Fix an error code in check_btf_func()	2020-06-04 23:38:54 +02:00