From f60a85cad677c4f9bb4cadd764f1d106c38c7cf8 Mon Sep 17 00:00:00 2001 From: Zqiang Date: Wed, 17 Mar 2021 11:09:15 +0800 Subject: bpf: Fix umd memory leak in copy_process() The syzbot reported a memleak as follows: BUG: memory leak unreferenced object 0xffff888101b41d00 (size 120): comm "kworker/u4:0", pid 8, jiffies 4294944270 (age 12.780s) backtrace: [] alloc_pid+0x66/0x560 [] copy_process+0x1465/0x25e0 [] kernel_clone+0xf3/0x670 [] kernel_thread+0x61/0x80 [] call_usermodehelper_exec_work [] call_usermodehelper_exec_work+0xc4/0x120 [] process_one_work+0x2c9/0x600 [] worker_thread+0x59/0x5d0 [] kthread+0x178/0x1b0 [] ret_from_fork+0x1f/0x30 unreferenced object 0xffff888110ef5c00 (size 232): comm "kworker/u4:0", pid 8414, jiffies 4294944270 (age 12.780s) backtrace: [] kmem_cache_zalloc [] __alloc_file+0x1f/0xf0 [] alloc_empty_file+0x69/0x120 [] alloc_file+0x33/0x1b0 [] alloc_file_pseudo+0xb2/0x140 [] create_pipe_files+0x138/0x2e0 [] umd_setup+0x33/0x220 [] call_usermodehelper_exec_async+0xb4/0x1b0 [] ret_from_fork+0x1f/0x30 After the UMD process exits, the pipe_to_umh/pipe_from_umh and tgid need to be released. Fixes: d71fa5c9763c ("bpf: Add kernel module with user mode driver that populates bpffs.") Reported-by: syzbot+44908bb56d2bfe56b28e@syzkaller.appspotmail.com Signed-off-by: Zqiang Signed-off-by: Daniel Borkmann Link: https://lore.kernel.org/bpf/20210317030915.2865-1-qiang.zhang@windriver.com --- include/linux/usermode_driver.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include') diff --git a/include/linux/usermode_driver.h b/include/linux/usermode_driver.h index 073a9e0ec07d..ad970416260d 100644 --- a/include/linux/usermode_driver.h +++ b/include/linux/usermode_driver.h @@ -14,5 +14,6 @@ struct umd_info { int umd_load_blob(struct umd_info *info, const void *data, size_t len); int umd_unload_blob(struct umd_info *info); int fork_usermode_driver(struct umd_info *info); +void umd_cleanup_helper(struct umd_info *info); #endif /* __LINUX_USERMODE_DRIVER_H__ */ -- cgit v1.2.3