Re: [syzbot] Re: [syzbot] [tomoyo?] WARNING in tomoyo_write_control

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Subject: Re: [syzbot] [tomoyo?] WARNING in tomoyo_write_control
Author: lizhi.xu@xxxxxxxxxxxxx

User input a too large avail length 0xfffffdeful.

#syz test

diff --git a/security/tomoyo/common.c b/security/tomoyo/common.c
index 5c7b059a332a..65458b4059ab 100644
--- a/security/tomoyo/common.c
+++ b/security/tomoyo/common.c
@@ -2654,6 +2654,8 @@ ssize_t tomoyo_write_control(struct tomoyo_io_buffer *head,
 
 	if (!head->write)
 		return -EINVAL;
+	if (avail_len << PAGE_SHIFT > MAX_PAGE_ORDER)
+		return -EINVAL;
 	if (mutex_lock_interruptible(&head->io_sem))
 		return -EINTR;
 	cp0 = head->write_buf;