6.8-stable review patch. If anyone has any objections, please let me know.
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From: Uros Bizjak ubizjak@gmail.com
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 joanbrugueram@gmail.com Signed-off-by: Joan Bruguera Micó joanbrugueram@gmail.com Signed-off-by: Uros Bizjak ubizjak@gmail.com Cc: Alexei Starovoitov ast@kernel.org Cc: Daniel Borkmann daniel@iogearbox.net Link: https://lore.kernel.org/r/20240401185821.224068-2-ubizjak@gmail.com Signed-off-by: Alexei Starovoitov ast@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- arch/x86/net/bpf_jit_comp.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/arch/x86/net/bpf_jit_comp.c +++ b/arch/x86/net/bpf_jit_comp.c @@ -466,7 +466,7 @@ static int emit_call(u8 **pprog, void *f 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); }