diff options
| author | Petr Mladek <pmladek@suse.com> | 2025-11-28 14:59:20 +0100 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2026-01-20 19:44:23 -0800 |
| commit | 3b07086444f80c844351255fd94c2cb0a7224df2 (patch) | |
| tree | 35f9298d4036fa313ed484402e235e2377e221ac /kernel | |
| parent | e8a1e7eaa19d0b757b06a2f913e3eeb4b1c002c6 (diff) | |
kallsyms: prevent module removal when printing module name and buildid
kallsyms_lookup_buildid() copies the symbol name into the given buffer so
that it can be safely read anytime later. But it just copies pointers to
mod->name and mod->build_id which might get reused after the related
struct module gets removed.
The lifetime of struct module is synchronized using RCU. Take the rcu
read lock for the entire __sprint_symbol().
Link: https://lkml.kernel.org/r/20251128135920.217303-8-pmladek@suse.com
Signed-off-by: Petr Mladek <pmladek@suse.com>
Reviewed-by: Aaron Tomlin <atomlin@atomlin.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkman <daniel@iogearbox.net>
Cc: Daniel Gomez <da.gomez@samsung.com>
Cc: John Fastabend <john.fastabend@gmail.com>
Cc: Kees Cook <kees@kernel.org>
Cc: Luis Chamberalin <mcgrof@kernel.org>
Cc: Marc Rutland <mark.rutland@arm.com>
Cc: "Masami Hiramatsu (Google)" <mhiramat@kernel.org>
Cc: Petr Pavlu <petr.pavlu@suse.com>
Cc: Sami Tolvanen <samitolvanen@google.com>
Cc: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/kallsyms.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/kernel/kallsyms.c b/kernel/kallsyms.c index 0f639c907336..e0813ca9469a 100644 --- a/kernel/kallsyms.c +++ b/kernel/kallsyms.c @@ -474,6 +474,9 @@ static int __sprint_symbol(char *buffer, unsigned long address, unsigned long offset, size; int len; + /* Prevent module removal until modname and modbuildid are printed */ + guard(rcu)(); + address += symbol_offset; len = kallsyms_lookup_buildid(address, &size, &offset, &modname, &buildid, buffer); |