From: KaFai Wan <mannkafai@gmail.com> mainline inclusion from mainline-v6.16-rc1 commit 86bc9c742426a16b52a10ef61f5b721aecca2344 category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/ICIMYR Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... -------------------------------- syzkaller reported an issue: WARNING: CPU: 3 PID: 217 at kernel/bpf/core.c:2357 __bpf_prog_ret0_warn+0xa/0x20 kernel/bpf/core.c:2357 Modules linked in: CPU: 3 UID: 0 PID: 217 Comm: kworker/u32:6 Not tainted 6.15.0-rc4-syzkaller-00040-g8bac8898fe39 RIP: 0010:__bpf_prog_ret0_warn+0xa/0x20 kernel/bpf/core.c:2357 Call Trace: <TASK> bpf_dispatcher_nop_func include/linux/bpf.h:1316 [inline] __bpf_prog_run include/linux/filter.h:718 [inline] bpf_prog_run include/linux/filter.h:725 [inline] cls_bpf_classify+0x74a/0x1110 net/sched/cls_bpf.c:105 ... When creating bpf program, 'fp->jit_requested' depends on bpf_jit_enable. This issue is triggered because of CONFIG_BPF_JIT_ALWAYS_ON is not set and bpf_jit_enable is set to 1, causing the arch to attempt JIT the prog, but jit failed due to FAULT_INJECTION. As a result, incorrectly treats the program as valid, when the program runs it calls `__bpf_prog_ret0_warn` and triggers the WARN_ON_ONCE(1). Reported-by: syzbot+0903f6d7f285e41cdf10@syzkaller.appspotmail.com Closes: https://lore.kernel.org/bpf/6816e34e.a70a0220.254cdc.002c.GAE@google.com Fixes: fa9dd599b4da ("bpf: get rid of pure_initcall dependency to enable jits") Signed-off-by: KaFai Wan <mannkafai@gmail.com> Link: https://lore.kernel.org/r/20250526133358.2594176-1-mannkafai@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Pu Lehui <pulehui@huawei.com> --- kernel/bpf/core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c index e968b07fd6b4..2ecaf891a167 100644 --- a/kernel/bpf/core.c +++ b/kernel/bpf/core.c @@ -2360,7 +2360,7 @@ struct bpf_prog *bpf_prog_select_runtime(struct bpf_prog *fp, int *err) /* In case of BPF to BPF calls, verifier did all the prep * work with regards to JITing, etc. */ - bool jit_needed = false; + bool jit_needed = fp->jit_requested; if (fp->bpf_func) goto finalize; -- 2.34.1