linux/kernel/bpf
Andrii Nakryiko 04ea3086c4 bpf: Prevent writable memory-mapping of read-only ringbuf pages
Only the very first page of BPF ringbuf that contains consumer position
counter is supposed to be mapped as writeable by user-space. Producer
position is read-only and can be modified only by the kernel code. BPF ringbuf
data pages are read-only as well and are not meant to be modified by
user-code to maintain integrity of per-record headers.

This patch allows to map only consumer position page as writeable and
everything else is restricted to be read-only. remap_vmalloc_range()
internally adds VM_DONTEXPAND, so all the established memory mappings can't be
extended, which prevents any future violations through mremap()'ing.

Fixes: 457f44363a ("bpf: Implement BPF ring buffer and verifier support for it")
Reported-by: Ryota Shiga (Flatt Security)
Reported-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
2021-05-11 13:31:10 +02:00
..
preload bpf: Fix umd memory leak in copy_process() 2021-03-19 22:23:19 +01:00
arraymap.c bpf: Add batched ops support for percpu array 2021-04-28 01:17:45 +02:00
bpf_inode_storage.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2021-03-25 15:31:22 -07:00
bpf_iter.c bpf: Add bpf_for_each_map_elem() helper 2021-02-26 13:23:52 -08:00
bpf_local_storage.c bpf: Prevent deadlock from recursive bpf_task_storage_[get|delete] 2021-02-26 11:51:48 -08:00
bpf_lru_list.c bpf_lru_list: Read double-checked variable once without lock 2021-02-10 15:54:26 -08:00
bpf_lru_list.h bpf: Fix a typo "inacitve" -> "inactive" 2020-04-06 21:54:10 +02:00
bpf_lsm.c Networking changes for 5.13. 2021-04-29 11:57:23 -07:00
bpf_struct_ops_types.h bpf: tcp: Support tcp_congestion_ops in bpf 2020-01-09 08:46:18 -08:00
bpf_struct_ops.c bpf: Fix fexit trampoline. 2021-03-18 00:22:51 +01:00
bpf_task_storage.c bpf: Make symbol 'bpf_task_storage_busy' static 2021-03-16 12:24:20 -07:00
btf.c bpf: Forbid trampoline attach for functions with variable arguments 2021-05-07 01:28:28 +02:00
cgroup.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next 2021-02-16 13:14:06 -08:00
core.c bpf: Remove unused parameter from ___bpf_prog_run 2021-04-03 01:38:52 +02:00
cpumap.c bpf, cpumap: Bulk skb using netif_receive_skb_list 2021-04-27 17:13:49 +02:00
devmap.c bpf, devmap: Move drop error path to devmap for XDP_REDIRECT 2021-03-18 16:38:51 +01:00
disasm.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2021-04-09 20:48:35 -07:00
disasm.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 295 2019-06-05 17:36:38 +02:00
dispatcher.c bpf: Remove bpf_image tree 2020-03-13 12:49:52 -07:00
hashtab.c kernel/bpf/: Fix misspellings using codespell tool 2021-03-16 12:22:20 -07:00
helpers.c bpf: Implement formatted output helpers with bstr_printf 2021-04-27 15:56:31 -07:00
inode.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next 2021-04-25 18:02:32 -07:00
local_storage.c bpf: Fix NULL pointer dereference in bpf_get_local_storage() helper 2021-03-25 18:31:36 -07:00
lpm_trie.c bpf: Add support for batched ops in LPM trie maps 2021-03-25 18:51:08 -07:00
Makefile bpf: Enable task local storage for tracing programs 2021-02-26 11:51:47 -08:00
map_in_map.c bpf: Relax max_entries check for most of the inner map types 2020-08-28 15:41:30 +02:00
map_in_map.h bpf: Add map_meta_equal map ops 2020-08-28 15:41:30 +02:00
map_iter.c bpf: Implement link_query callbacks in map element iterators 2020-08-21 14:01:39 -07:00
net_namespace.c bpf: Add support for forced LINK_DETACH command 2020-08-01 20:38:28 -07:00
offload.c bpf, offload: Replace bitwise AND by logical AND in bpf_prog_offload_info_fill 2020-02-17 16:53:49 +01:00
percpu_freelist.c bpf: Use raw_spin_trylock() for pcpu_freelist_push/pop in NMI 2020-10-06 00:04:11 +02:00
percpu_freelist.h bpf: Use raw_spin_trylock() for pcpu_freelist_push/pop in NMI 2020-10-06 00:04:11 +02:00
prog_iter.c bpf: Refactor bpf_iter_reg to have separate seq_info member 2020-07-25 20:16:32 -07:00
queue_stack_maps.c bpf: Eliminate rlimit-based memory accounting for queue_stack_maps maps 2020-12-02 18:32:46 -08:00
reuseport_array.c bpf: Eliminate rlimit-based memory accounting for reuseport_array maps 2020-12-02 18:32:47 -08:00
ringbuf.c bpf: Prevent writable memory-mapping of read-only ringbuf pages 2021-05-11 13:31:10 +02:00
stackmap.c bpf: Refcount task stack in bpf_get_task_stack 2021-04-01 13:58:07 -07:00
syscall.c bpf: Allow trampoline re-attach for tracing and lsm programs 2021-04-25 21:09:01 -07:00
sysfs_btf.c bpf: Load and verify kernel module BTFs 2020-11-10 15:25:53 -08:00
task_iter.c bpf: Introduce task_vma bpf_iter 2021-02-12 12:56:53 -08:00
tnum.c bpf: Verifier, do explicit ALU32 bounds tracking 2020-03-30 14:59:53 -07:00
trampoline.c bpf: Allow trampoline re-attach for tracing and lsm programs 2021-04-25 21:09:01 -07:00
verifier.c bpf: Fix alu32 const subreg bound tracking on bitwise operations 2021-05-11 08:55:53 +02:00