From: Steven Rostedt Date: Thu, 1 May 2025 19:19:09 +0000 (-0400) Subject: tracing: Fix trace_adjust_address() when there is no modules in scratch area X-Git-Tag: v6.15-rc5~2^2~1 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=1be8e54a1e0f0a4bf70e3d65f94ca1738ee4f1f3;p=thirdparty%2Fkernel%2Flinux.git tracing: Fix trace_adjust_address() when there is no modules in scratch area The function trace_adjust_address() is used to map addresses of modules stored in the persistent memory and are also loaded in the current boot to return the current address for the module. If there's only one module entry, it will simply use that, otherwise it performs a bsearch of the entry array to find the modules to offset with. The issue is if there are no modules in the array. The code does not account for that and ends up referencing the first element in the array which does not exist and causes a crash. If nr_entries is zero, exit out early as if this was a core kernel address. Cc: Masami Hiramatsu Cc: Mathieu Desnoyers Link: https://lore.kernel.org/20250501151909.65910359@gandalf.local.home Fixes: 35a380ddbc653 ("tracing: Show last module text symbols in the stacktrace") Signed-off-by: Steven Rostedt (Google) --- diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 6d52dc108f007..5b8db27fb6ef3 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -6043,8 +6043,10 @@ unsigned long trace_adjust_address(struct trace_array *tr, unsigned long addr) tscratch = tr->scratch; /* if there is no tscrach, module_delta must be NULL. */ module_delta = READ_ONCE(tr->module_delta); - if (!module_delta || tscratch->entries[0].mod_addr > addr) + if (!module_delta || !tscratch->nr_entries || + tscratch->entries[0].mod_addr > addr) { return addr + tr->text_delta; + } /* Note that entries must be sorted. */ nr_entries = tscratch->nr_entries;