Hello, syzbot found the following crash on: HEAD commit: bef7b2a7 Merge tag 'devicetree-for-5.7' of git://git.kerne.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=16940efbe00000 kernel config: https://syzkaller.appspot.com/x/.config?x=f72ba8a207627d60 dashboard link: https://syzkaller.appspot.com/bug?extid=b4501d3e966ff59f6090 compiler: clang version 10.0.0 (https://github.com/llvm/llvm-project/ c2443155a0fb245c8f17f2c1c72b6ea391e86e81) syz repro: https://syzkaller.appspot.com/x/repro.syz?x=15d79efbe00000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1705901be00000 The bug was bisected to: commit 4426e945df588f2878affddf88a51259200f7e29 Author: Peter Xu <peterx@xxxxxxxxxx> Date: Thu Apr 2 04:08:49 2020 +0000 mm/gup: allow VM_FAULT_RETRY for multiple times bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=1441b1fbe00000 final crash: https://syzkaller.appspot.com/x/report.txt?x=1641b1fbe00000 console output: https://syzkaller.appspot.com/x/log.txt?x=1241b1fbe00000 IMPORTANT: if you fix the bug, please add the following tag to the commit: Reported-by: syzbot+b4501d3e966ff59f6090@xxxxxxxxxxxxxxxxxxxxxxxxx Fixes: 4426e945df58 ("mm/gup: allow VM_FAULT_RETRY for multiple times") ================================================================== BUG: KASAN: user-memory-access in atomic_read include/asm-generic/atomic-instrumented.h:26 [inline] BUG: KASAN: user-memory-access in page_ref_count include/linux/page_ref.h:67 [inline] BUG: KASAN: user-memory-access in put_page_testzero include/linux/mm.h:675 [inline] BUG: KASAN: user-memory-access in put_page+0x110/0x1d0 include/linux/mm.h:1136 Read of size 4 at addr 00003fbf7e8680b0 by task syz-executor574/7201 CPU: 0 PID: 7201 Comm: syz-executor574 Not tainted 5.6.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1e9/0x30e lib/dump_stack.c:118 __kasan_report+0x122/0x190 mm/kasan/report.c:507 kasan_report+0x4d/0x80 mm/kasan/common.c:648 ================================================================== Kernel panic - not syncing: panic_on_warn set ... CPU: 0 PID: 7201 Comm: syz-executor574 Tainted: G B 5.6.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1e9/0x30e lib/dump_stack.c:118 panic+0x264/0x7a0 kernel/panic.c:221 end_report mm/kasan/report.c:96 [inline] __kasan_report+0x187/0x190 mm/kasan/report.c:510 kasan_report+0x4d/0x80 mm/kasan/common.c:648 Kernel Offset: disabled Rebooting in 86400 seconds.. --- This bug is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at syzkaller@xxxxxxxxxxxxxxxx. syzbot will keep track of this bug report. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot. For information about bisection process see: https://goo.gl/tpsmEJ#bisection syzbot can test patches for this bug, for details see: https://goo.gl/tpsmEJ#testing-patches
