linux/kernel/bpf
Toke Høiland-Jørgensen f858c2b2ca bpf: Fix calling global functions from BPF_PROG_TYPE_EXT programs
The verifier allows programs to call global functions as long as their
argument types match, using BTF to check the function arguments. One of the
allowed argument types to such global functions is PTR_TO_CTX; however the
check for this fails on BPF_PROG_TYPE_EXT functions because the verifier
uses the wrong type to fetch the vmlinux BTF ID for the program context
type. This failure is seen when an XDP program is loaded using
libxdp (which loads it as BPF_PROG_TYPE_EXT and attaches it to a global XDP
type program).

Fix the issue by passing in the target program type instead of the
BPF_PROG_TYPE_EXT type to bpf_prog_get_ctx() when checking function
argument compatibility.

The first Fixes tag refers to the latest commit that touched the code in
question, while the second one points to the code that first introduced
the global function call verification.

v2:
- Use resolve_prog_type()

Fixes: 3363bd0cfb ("bpf: Extend kfunc with PTR_TO_CTX, PTR_TO_MEM argument support")
Fixes: 51c39bb1d5 ("bpf: Introduce function-by-function verification")
Reported-by: Simon Sundberg <simon.sundberg@kau.se>
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Link: https://lore.kernel.org/r/20220606075253.28422-1-toke@redhat.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-06-07 10:41:20 -07:00
..
preload bpf: Remove redundant slash 2022-03-07 22:19:32 -08:00
arraymap.c bpf: add bpf_map_lookup_percpu_elem for percpu map 2022-05-11 18:16:54 -07:00
bloom_filter.c bpf: Compute map_btf_id during build time 2022-04-26 11:35:21 -07:00
bpf_inode_storage.c bpf: Compute map_btf_id during build time 2022-04-26 11:35:21 -07:00
bpf_iter.c bpf: Remove redundant assignment to meta.seq in __task_seq_show() 2022-04-11 21:14:34 +02:00
bpf_local_storage.c bpf: Fix usage of trace RCU in local storage. 2022-04-19 17:55:45 -07:00
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 printk: stop including cache.h from printk.h 2022-05-13 07:20:07 -07:00
bpf_lsm.c bpf, x86: Attach a cookie to fentry/fexit/fmod_ret/lsm. 2022-05-10 21:58:31 -07:00
bpf_struct_ops_types.h bpf: Add dummy BPF STRUCT_OPS for test purpose 2021-11-01 14:10:00 -07:00
bpf_struct_ops.c bpf, x86: Generate trampolines from bpf_tramp_links 2022-05-10 17:50:40 -07:00
bpf_task_storage.c bpf: Compute map_btf_id during build time 2022-04-26 11:35:21 -07:00
btf.c bpf: Fix calling global functions from BPF_PROG_TYPE_EXT programs 2022-06-07 10:41:20 -07:00
cgroup.c bpf: Use bpf_prog_run_array_cg_flags everywhere 2022-04-25 17:03:57 -07:00
core.c bpf: Fix probe read error in ___bpf_prog_run() 2022-05-28 01:09:18 +02:00
cpumap.c bpf: Compute map_btf_id during build time 2022-04-26 11:35:21 -07:00
devmap.c bpf: Compute map_btf_id during build time 2022-04-26 11:35:21 -07:00
disasm.c bpf: Relicense disassembler as GPL-2.0-only OR BSD-2-Clause 2021-09-02 14:49:23 +02:00
disasm.h bpf: Relicense disassembler as GPL-2.0-only OR BSD-2-Clause 2021-09-02 14:49:23 +02:00
dispatcher.c
hashtab.c bpf: add bpf_map_lookup_percpu_elem for percpu map 2022-05-11 18:16:54 -07:00
helpers.c bpf: Add dynptr data slices 2022-05-23 14:31:28 -07:00
inode.c bpf: Convert bpf_preload.ko to use light skeleton. 2022-02-10 23:31:51 +01:00
Kconfig rcu: Make the TASKS_RCU Kconfig option be selected 2022-04-20 16:52:58 -07:00
link_iter.c bpf: Add bpf_link iterator 2022-05-10 11:20:45 -07:00
local_storage.c bpf: Compute map_btf_id during build time 2022-04-26 11:35:21 -07:00
lpm_trie.c bpf: Compute map_btf_id during build time 2022-04-26 11:35:21 -07:00
Makefile bpf: Add bpf_link iterator 2022-05-10 11:20:45 -07:00
map_in_map.c bpf: Allow storing unreferenced kptr in map 2022-04-25 17:31:35 -07:00
map_in_map.h bpf: Add map_meta_equal map ops 2020-08-28 15:41:30 +02:00
map_iter.c bpf: Introduce MEM_RDONLY flag 2021-12-18 13:27:41 -08:00
mmap_unlock_work.h bpf: Introduce helper bpf_find_vma 2021-11-07 11:54:51 -08:00
net_namespace.c net: Add includes masked by netdevice.h including uapi/bpf.h 2021-12-29 20:03:05 -08:00
offload.c
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
queue_stack_maps.c bpf: Compute map_btf_id during build time 2022-04-26 11:35:21 -07:00
reuseport_array.c bpf: Compute map_btf_id during build time 2022-04-26 11:35:21 -07:00
ringbuf.c bpf: Dynptr support for ring buffers 2022-05-23 14:31:28 -07:00
stackmap.c bpf: Compute map_btf_id during build time 2022-04-26 11:35:21 -07:00
syscall.c bpf: refine kernel.unprivileged_bpf_disabled behaviour 2022-05-20 19:48:29 -07:00
sysfs_btf.c bpf: Load and verify kernel module BTFs 2020-11-10 15:25:53 -08:00
task_iter.c bpf: Remove redundant assignment to meta.seq in __task_seq_show() 2022-04-11 21:14:34 +02:00
tnum.c bpf, tnums: Provably sound, faster, and more precise algorithm for tnum_mul 2021-06-01 13:34:15 +02:00
trampoline.c bpf: Fix potential array overflow in bpf_trampoline_get_progs() 2022-05-11 21:24:20 -07:00
verifier.c bpf: Add dynptr data slices 2022-05-23 14:31:28 -07:00