From: Petr Mladek <pmladek@suse.com> mainline inclusion from mainline-v7.0-rc1 commit 3b07086444f80c844351255fd94c2cb0a7224df2 category: bugfix bugzilla: https://atomgit.com/openeuler/kernel/issues/9956 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... -------------------------------- 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> Conflicts: kernel/kallsyms.c [Context conflict] Signed-off-by: Tengda Wu <wutengda2@huawei.com> --- kernel/kallsyms.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/kernel/kallsyms.c b/kernel/kallsyms.c index 78b5bda6f531..0919c4dd9d8b 100644 --- a/kernel/kallsyms.c +++ b/kernel/kallsyms.c @@ -485,6 +485,9 @@ 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; name = kallsyms_lookup_buildid(address, &size, &offset, &modname, &buildid, buffer); -- 2.34.1