From 3f9d57c771656bfd651e22edcfdb5f60e62542d4 Mon Sep 17 00:00:00 2001 From: Uros Bizjak Date: Mon, 1 Apr 2024 20:55:29 +0200 Subject: [PATCH] x86/bpf: Fix IP after emitting call depth accounting MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit commit 9d98aa088386aee3db1b7b60b800c0fde0654a4a upstream. Adjust the IP passed to `emit_patch` so it calculates the correct offset for the CALL instruction if `x86_call_depth_emit_accounting` emits code. Otherwise we will skip some instructions and most likely crash. Fixes: b2e9dfe54be4 ("x86/bpf: Emit call depth accounting if required") Link: https://lore.kernel.org/lkml/20230105214922.250473-1-joanbrugueram@gmail.com/ Co-developed-by: Joan Bruguera Micó Signed-off-by: Joan Bruguera Micó Signed-off-by: Uros Bizjak Cc: Alexei Starovoitov Cc: Daniel Borkmann Link: https://lore.kernel.org/r/20240401185821.224068-2-ubizjak@gmail.com Signed-off-by: Alexei Starovoitov Signed-off-by: Greg Kroah-Hartman --- arch/x86/net/bpf_jit_comp.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/net/bpf_jit_comp.c b/arch/x86/net/bpf_jit_comp.c index 955133077c10..a6a4d3ca8ddc 100644 --- a/arch/x86/net/bpf_jit_comp.c +++ b/arch/x86/net/bpf_jit_comp.c @@ -344,7 +344,7 @@ static int emit_call(u8 **pprog, void *func, void *ip) static int emit_rsb_call(u8 **pprog, void *func, void *ip) { OPTIMIZER_HIDE_VAR(func); - x86_call_depth_emit_accounting(pprog, func); + ip += x86_call_depth_emit_accounting(pprog, func); return emit_patch(pprog, func, ip, 0xE8); }