+++ Leon Yu [06/03/18 23:16 +0800]:

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

Ah yeah, the error code was dropped in that commit.

Applied, thanks for the fix.

Jessica

---

kernel/module.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/module.c b/kernel/module.c index ad2d420024f6..e42764acedb4 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 = {

2.16.2