From 98bf5bc8cb8cbc4c33b3da38e529e6fe591868cb Mon Sep 17 00:00:00 2001 From: Ian Rogers Date: Wed, 7 Jan 2026 16:26:25 -0800 Subject: [PATCH] tracing: Avoid possible signed 64-bit truncation [ Upstream commit 00f13e28a9c3acd40f0551cde7e9d2d1a41585bf ] 64-bit truncation to 32-bit can result in the sign of the truncated value changing. The cmp_mod_entry is used in bsearch and so the truncation could result in an invalid search order. This would only happen were the addresses more than 2GB apart and so unlikely, but let's fix the potentially broken compare anyway. Cc: Mathieu Desnoyers Link: https://patch.msgid.link/20260108002625.333331-1-irogers@google.com Signed-off-by: Ian Rogers Acked-by: Masami Hiramatsu (Google) Signed-off-by: Steven Rostedt (Google) Signed-off-by: Sasha Levin --- kernel/trace/trace.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 142e3b737f0b..907923d5f8bb 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -6061,10 +6061,10 @@ static int cmp_mod_entry(const void *key, const void *pivot) unsigned long addr = (unsigned long)key; const struct trace_mod_entry *ent = pivot; - if (addr >= ent[0].mod_addr && addr < ent[1].mod_addr) - return 0; - else - return addr - ent->mod_addr; + if (addr < ent[0].mod_addr) + return -1; + + return addr >= ent[1].mod_addr; } /**