[syzbot] KASAN: invalid-access Read in copy_page

From: syzbot <syzbot+c2c79c6d6eddc5262b77@syzkaller.appspotmail.com>
To: andreyknvl@gmail.com, catalin.marinas@arm.com,
	 linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org,  syzkaller-bugs@googlegroups.com,
	tongtiangen@huawei.com,  vincenzo.frascino@arm.com,
	wangkefeng.wang@huawei.com, will@kernel.org
Subject: [syzbot] KASAN: invalid-access Read in copy_page
Date: Fri, 05 Aug 2022 18:31:21 -0700	[thread overview]
Message-ID: <0000000000004387dc05e5888ae5@google.com> (raw)

Hello,

syzbot found the following issue on:

HEAD commit:    9e2f40233670 Merge tag 'x86_sgx_for_v6.0-2022-08-03.1' of ..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=16181cbc080000
kernel config:  https://syzkaller.appspot.com/x/.config?x=886e7348b2982e4d
dashboard link: https://syzkaller.appspot.com/bug?extid=c2c79c6d6eddc5262b77
compiler:       aarch64-linux-gnu-gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
userspace arch: arm64

Unfortunately, I don't have any reproducer for this issue yet.

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+c2c79c6d6eddc5262b77@syzkaller.appspotmail.com

==================================================================
BUG: KASAN: invalid-access in copy_page+0x10/0xd0 arch/arm64/lib/copy_page.S:26
Read at addr f5ff000017f2e000 by task syz-executor.1/2218
Pointer tag: [f5], memory tag: [f2]

CPU: 1 PID: 2218 Comm: syz-executor.1 Not tainted 5.19.0-syzkaller-10532-g9e2f40233670 #0
Hardware name: linux,dummy-virt (DT)
Call trace:
 dump_backtrace.part.0+0xcc/0xe0 arch/arm64/kernel/stacktrace.c:182
 dump_backtrace arch/arm64/kernel/stacktrace.c:188 [inline]
 show_stack+0x18/0x5c arch/arm64/kernel/stacktrace.c:189
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x68/0x84 lib/dump_stack.c:106
 print_address_description mm/kasan/report.c:313 [inline]
 print_report+0xfc/0x5f0 mm/kasan/report.c:429
 kasan_report+0x8c/0xb0 mm/kasan/report.c:491
 __do_kernel_fault+0x104/0x1c0 arch/arm64/mm/fault.c:319
 do_bad_area arch/arm64/mm/fault.c:469 [inline]
 do_tag_check_fault+0x78/0x90 arch/arm64/mm/fault.c:738
 do_mem_abort+0x48/0xa0 arch/arm64/mm/fault.c:814
 el1_abort+0x40/0x60 arch/arm64/kernel/entry-common.c:366
 el1h_64_sync_handler+0xb0/0xd0 arch/arm64/kernel/entry-common.c:417
 el1h_64_sync+0x64/0x68 arch/arm64/kernel/entry.S:576
 copy_page+0x10/0xd0 arch/arm64/lib/copy_page.S:26
 copy_user_highpage+0x18/0x4c arch/arm64/mm/copypage.c:34
 __wp_page_copy_user mm/memory.c:2848 [inline]
 wp_page_copy+0xa0/0x790 mm/memory.c:3109
 do_wp_page+0x150/0x6a4 mm/memory.c:3471
 handle_pte_fault mm/memory.c:4925 [inline]
 __handle_mm_fault+0x6c4/0xf84 mm/memory.c:5046
 handle_mm_fault+0xe8/0x25c mm/memory.c:5144
 __do_page_fault arch/arm64/mm/fault.c:502 [inline]
 do_page_fault+0x140/0x3b0 arch/arm64/mm/fault.c:602
 do_mem_abort+0x48/0xa0 arch/arm64/mm/fault.c:814
 el0_da+0x48/0xbc arch/arm64/kernel/entry-common.c:502
 el0t_64_sync_handler+0x134/0x1b0 arch/arm64/kernel/entry-common.c:645
 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:581

The buggy address belongs to the physical page:
page:000000003e6672be refcount:3 mapcount:2 mapping:0000000000000000 index:0xffffffffe pfn:0x57f2e
memcg:fbff00001ded8000
anon flags: 0x1ffc2800208001c(uptodate|dirty|lru|swapbacked|arch_2|node=0|zone=0|lastcpupid=0x7ff|kasantag=0xa)
raw: 01ffc2800208001c fffffc00004f91c8 fcff00001d1b1000 f1ff00000510b231
raw: 0000000ffffffffe 0000000000000000 0000000300000001 fbff00001ded8000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff000017f2de00: f5 f5 f5 f5 f5 f5 f5 f5 f5 f5 f5 f5 f5 f5 f5 f5
 ffff000017f2df00: f5 f5 f5 f5 f5 f5 f5 f5 f5 f5 f5 f5 f5 f5 f5 f5
>ffff000017f2e000: f2 f2 f2 f2 f2 f2 f2 f2 f2 f2 f2 f2 f2 f2 f2 f2
                   ^
 ffff000017f2e100: f2 f2 f2 f2 f2 f2 f2 f2 f2 f2 f2 f2 f2 f2 f2 f2
 ffff000017f2e200: f2 f2 f2 f2 f2 f2 f2 f2 f2 f2 f2 f2 f2 f2 f2 f2
==================================================================

---
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