[PATCH bpf-next v3 2/9] s390/bpf: Fix memory leak in bpf_jit_free

[Pu Lehui]

From: Pu Lehui <pulehui@xxxxxxxxxx>

If a subprogram fails to JIT in jit_subprogs(), previously JITed
subprograms are freed. However, the generic bpf_jit_free() fails to
free their leftover jit_data, causing a memory leak.

Implement a custom bpf_jit_free() to free this data.

Fixes: 1c8f9b91c456 ("bpf: s390: add JIT support for multi-function programs")
Reported-by: Sashiko <sashiko-bot@xxxxxxxxxx>
Signed-off-by: Pu Lehui <pulehui@xxxxxxxxxx>
---
 arch/s390/net/bpf_jit_comp.c | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/arch/s390/net/bpf_jit_comp.c b/arch/s390/net/bpf_jit_comp.c
index b60877478b45..bf100e794e27 100644
--- a/arch/s390/net/bpf_jit_comp.c
+++ b/arch/s390/net/bpf_jit_comp.c
@@ -3106,3 +3106,22 @@ bool bpf_jit_inlines_helper_call(s32 imm)
 		return false;
 	}
 }
+
+void bpf_jit_free(struct bpf_prog *fp)
+{
+	if (fp->jited) {
+		struct s390_jit_data *jit_data = fp->aux->jit_data;
+		struct bpf_binary_header *hdr = bpf_jit_binary_hdr(fp);
+
+		/* Cleanup for earlier subprogs if jit_subprogs() aborts */
+		if (jit_data) {
+			kvfree(jit_data->ctx.addrs);
+			kfree(jit_data);
+		}
+
+		bpf_jit_binary_free(hdr);
+		WARN_ON_ONCE(!bpf_prog_kallsyms_verify_off(fp));
+	}
+
+	bpf_prog_unlock_free(fp);
+}
-- 
2.34.1