linux/tools
Mingyi Zhang fc3a5534e2 libbpf: Fix NULL pointer dereference in bpf_object__collect_prog_relos
An issue occurred while reading an ELF file in libbpf.c during fuzzing:

	Program received signal SIGSEGV, Segmentation fault.
	0x0000000000958e97 in bpf_object.collect_prog_relos () at libbpf.c:4206
	4206 in libbpf.c
	(gdb) bt
	#0 0x0000000000958e97 in bpf_object.collect_prog_relos () at libbpf.c:4206
	#1 0x000000000094f9d6 in bpf_object.collect_relos () at libbpf.c:6706
	#2 0x000000000092bef3 in bpf_object_open () at libbpf.c:7437
	#3 0x000000000092c046 in bpf_object.open_mem () at libbpf.c:7497
	#4 0x0000000000924afa in LLVMFuzzerTestOneInput () at fuzz/bpf-object-fuzzer.c:16
	#5 0x000000000060be11 in testblitz_engine::fuzzer::Fuzzer::run_one ()
	#6 0x000000000087ad92 in tracing::span::Span::in_scope ()
	#7 0x00000000006078aa in testblitz_engine::fuzzer::util::walkdir ()
	#8 0x00000000005f3217 in testblitz_engine::entrypoint::main::{{closure}} ()
	#9 0x00000000005f2601 in main ()
	(gdb)

scn_data was null at this code(tools/lib/bpf/src/libbpf.c):

	if (rel->r_offset % BPF_INSN_SZ || rel->r_offset >= scn_data->d_size) {

The scn_data is derived from the code above:

	scn = elf_sec_by_idx(obj, sec_idx);
	scn_data = elf_sec_data(obj, scn);

	relo_sec_name = elf_sec_str(obj, shdr->sh_name);
	sec_name = elf_sec_name(obj, scn);
	if (!relo_sec_name || !sec_name)// don't check whether scn_data is NULL
		return -EINVAL;

In certain special scenarios, such as reading a malformed ELF file,
it is possible that scn_data may be a null pointer

Signed-off-by: Mingyi Zhang <zhangmingyi5@huawei.com>
Signed-off-by: Xin Liu <liuxin350@huawei.com>
Signed-off-by: Changye Wu <wuchangye@huawei.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20231221033947.154564-1-liuxin350@huawei.com
2023-12-21 10:05:42 +01:00
..
accounting
arch perf tools fixes for v6.7: 1st batch 2023-12-01 10:17:16 +09:00
bootconfig
bpf bpftool: Add support to display uprobe_multi links 2023-11-28 21:50:09 -08:00
build perf tools fixes for v6.6: 2nd batch 2023-10-30 13:46:27 -07:00
certs
cgroup
counter
crypto/ccp crypto: ccp - Fix some unfused tests 2023-09-15 18:29:45 +08:00
debugging
edid
firewire
firmware
gpio
hv hv/hv_kvp_daemon: Some small fixes for handling NM keyfiles 2023-11-10 23:27:46 +00:00
iio tools: iio: iio_generic_buffer ensure alignment 2023-10-05 16:16:20 +01:00
include Revert BPF token-related functionality 2023-12-19 08:23:03 -08:00
kvm/kvm_stat
laptop
leds
lib libbpf: Fix NULL pointer dereference in bpf_object__collect_prog_relos 2023-12-21 10:05:42 +01:00
memory-model
mm tools/mm: update the usage output to be more organized 2023-10-18 14:34:19 -07:00
net/ynl tools/net/ynl-gen-rst: Remove extra indentation from generated docs 2023-12-18 14:39:44 -08:00
objtool * Refactor and clean up TDX hypercall/module call infrastructure 2023-11-01 10:28:32 -10:00
pci
pcmcia
perf perf list: Fix JSON segfault by setting the used skip_duplicate_pmus callback 2023-12-05 11:16:00 -08:00
power PM: tools: Fix sleepgraph syntax error 2023-11-20 17:59:58 +01:00
rcu
scripts tools/build: Fix -s detection code in tools/scripts/Makefile.include 2023-10-18 15:29:47 -07:00
spi
testing selftests/bpf: Remove tests for zeroed-array kptr 2023-12-20 13:25:46 -08:00
thermal tools/thermal: Remove unused 'mds' and 'nrhandler' variables 2023-10-15 23:40:10 +02:00
time
tracing rtla: Fix uninitialized variable found 2023-10-30 19:00:12 +01:00
usb
verification verification/dot2k: Delete duplicate imports 2023-10-30 16:59:12 +01:00
virtio tools/virtio: Add dma sync api for virtio test 2023-10-16 05:32:23 -04:00
wmi
workqueue
Makefile