module: propagate error in modules_open()
otherwise kernel can oops later in seq_release() due to dereferencing null
file->private_data which is only set if seq_open() succeeds.
BUG: unable to handle kernel NULL pointer dereference at 0000000000000000
IP: seq_release+0xc/0x30
Call Trace:
close_pdeo+0x37/0xd0
proc_reg_release+0x5d/0x60
__fput+0x9d/0x1d0
____fput+0x9/0x10
task_work_run+0x75/0x90
do_exit+0x252/0xa00
do_group_exit+0x36/0xb0
SyS_exit_group+0xf/0x10
Fixes: 516fb7f2e73d ("/proc/module: use the same logic as /proc/kallsyms for address exposure")
Cc: Jessica Yu <jeyu@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: stable@vger.kernel.org # 4.15+
Signed-off-by: Leon Yu <chianglungyu@gmail.com>
Signed-off-by: Jessica Yu <jeyu@kernel.org>
diff --git a/kernel/module.c b/kernel/module.c
index ad2d420..e42764a 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -4228,7 +4228,7 @@ static int modules_open(struct inode *inode, struct file *file)
m->private = kallsyms_show_value() ? NULL : (void *)8ul;
}
- return 0;
+ return err;
}
static const struct file_operations proc_modules_operations = {