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authorToke Høiland-Jørgensen <toke@redhat.com>2019-12-10 19:14:12 +0100
committerDaniel Borkmann <daniel@iogearbox.net>2019-12-11 13:57:26 +0100
commit5b79bcdf03628a3a9ee04d9cd5fabcf61a8e20be (patch)
treec3f21a9c363b0b320e5678a69b1d847d733cb5ef /tools
parent4c80c7bc583a87ded5f61906f81256b57c795806 (diff)
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bpftool: Don't crash on missing jited insns or ksyms
When the kptr_restrict sysctl is set, the kernel can fail to return jited_ksyms or jited_prog_insns, but still have positive values in nr_jited_ksyms and jited_prog_len. This causes bpftool to crash when trying to dump the program because it only checks the len fields not the actual pointers to the instructions and ksyms. Fix this by adding the missing checks. Fixes: 71bb428fe2c1 ("tools: bpf: add bpftool") Fixes: f84192ee00b7 ("tools: bpftool: resolve calls without using imm field") Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/bpf/20191210181412.151226-1-toke@redhat.com
Diffstat (limited to 'tools')
-rw-r--r--tools/bpf/bpftool/prog.c2
-rw-r--r--tools/bpf/bpftool/xlated_dumper.c2
2 files changed, 2 insertions, 2 deletions
diff --git a/tools/bpf/bpftool/prog.c b/tools/bpf/bpftool/prog.c
index 4535c863d2cd..2ce9c5ba1934 100644
--- a/tools/bpf/bpftool/prog.c
+++ b/tools/bpf/bpftool/prog.c
@@ -493,7 +493,7 @@ static int do_dump(int argc, char **argv)
info = &info_linear->info;
if (mode == DUMP_JITED) {
- if (info->jited_prog_len == 0) {
+ if (info->jited_prog_len == 0 || !info->jited_prog_insns) {
p_info("no instructions returned");
goto err_free;
}
diff --git a/tools/bpf/bpftool/xlated_dumper.c b/tools/bpf/bpftool/xlated_dumper.c
index 494d7ae3614d..5b91ee65a080 100644
--- a/tools/bpf/bpftool/xlated_dumper.c
+++ b/tools/bpf/bpftool/xlated_dumper.c
@@ -174,7 +174,7 @@ static const char *print_call(void *private_data,
struct kernel_sym *sym;
if (insn->src_reg == BPF_PSEUDO_CALL &&
- (__u32) insn->imm < dd->nr_jited_ksyms)
+ (__u32) insn->imm < dd->nr_jited_ksyms && dd->jited_ksyms)
address = dd->jited_ksyms[insn->imm];
sym = kernel_syms_search(dd, address);