From f6223ff799666235a80d05f8137b73e5580077b9 Mon Sep 17 00:00:00 2001 From: Ye Bin Date: Thu, 18 Nov 2021 09:59:07 +0800 Subject: [PATCH] io_uring: Fix undefined-behaviour in io_issue_sqe We got issue as follows: ================================================================================ UBSAN: Undefined behaviour in ./include/linux/ktime.h:42:14 signed integer overflow: -4966321760114568020 * 1000000000 cannot be represented in type 'long long int' CPU: 1 PID: 2186 Comm: syz-executor.2 Not tainted 4.19.90+ #12 Hardware name: linux,dummy-virt (DT) Call trace: dump_backtrace+0x0/0x3f0 arch/arm64/kernel/time.c:78 show_stack+0x28/0x38 arch/arm64/kernel/traps.c:158 __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x170/0x1dc lib/dump_stack.c:118 ubsan_epilogue+0x18/0xb4 lib/ubsan.c:161 handle_overflow+0x188/0x1dc lib/ubsan.c:192 __ubsan_handle_mul_overflow+0x34/0x44 lib/ubsan.c:213 ktime_set include/linux/ktime.h:42 [inline] timespec64_to_ktime include/linux/ktime.h:78 [inline] io_timeout fs/io_uring.c:5153 [inline] io_issue_sqe+0x42c8/0x4550 fs/io_uring.c:5599 __io_queue_sqe+0x1b0/0xbc0 fs/io_uring.c:5988 io_queue_sqe+0x1ac/0x248 fs/io_uring.c:6067 io_submit_sqe fs/io_uring.c:6137 [inline] io_submit_sqes+0xed8/0x1c88 fs/io_uring.c:6331 __do_sys_io_uring_enter fs/io_uring.c:8170 [inline] __se_sys_io_uring_enter fs/io_uring.c:8129 [inline] __arm64_sys_io_uring_enter+0x490/0x980 fs/io_uring.c:8129 invoke_syscall arch/arm64/kernel/syscall.c:53 [inline] el0_svc_common+0x374/0x570 arch/arm64/kernel/syscall.c:121 el0_svc_handler+0x190/0x260 arch/arm64/kernel/syscall.c:190 el0_svc+0x10/0x218 arch/arm64/kernel/entry.S:1017 ================================================================================ As ktime_set only judge 'secs' if big than KTIME_SEC_MAX, but if we pass negative value maybe lead to overflow. To address this issue, we must check if 'sec' is negative. Signed-off-by: Ye Bin Link: https://lore.kernel.org/r/20211118015907.844807-1-yebin10@huawei.com Signed-off-by: Jens Axboe --- fs/io_uring.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/fs/io_uring.c b/fs/io_uring.c index 8a2b73c..c4f2176 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -6196,6 +6196,9 @@ static int io_timeout_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe, if (get_timespec64(&data->ts, u64_to_user_ptr(sqe->addr))) return -EFAULT; + if (data->ts.tv_sec < 0 || data->ts.tv_nsec < 0) + return -EINVAL; + data->mode = io_translate_timeout_mode(flags); hrtimer_init(&data->timer, io_timeout_get_clock(data), data->mode); -- 2.7.4