Hello, syzbot found the following issue on:
HEAD commit: 860461e4 Add linux-next specific files for 20200917 git tree: linux-next console output: https://syzkaller.appspot.com/x/log.txt?x=141fc5d9900000 kernel config: https://syzkaller.appspot.com/x/.config?x=f2392812d6c63d5c dashboard link: https://syzkaller.appspot.com/bug?extid=1d393803acac53c985a0 compiler: gcc (GCC) 10.1.0-syz 20200507 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=16778b07900000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1216f8ad900000 IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+1d393803acac53c98...@syzkaller.appspotmail.com ================================================================== BUG: KASAN: stack-out-of-bounds in memcpy include/linux/string.h:399 [inline] BUG: KASAN: stack-out-of-bounds in read_extent_buffer+0x114/0x150 fs/btrfs/extent_io.c:5674 Write of size 8 at addr ffffc90000dd79f0 by task kworker/u4:1/21 CPU: 1 PID: 21 Comm: kworker/u4:1 Not tainted 5.9.0-rc5-next-20200917-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: btrfs-endio-meta btrfs_work_helper Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x198/0x1fb lib/dump_stack.c:118 print_address_description.constprop.0.cold+0x5/0x497 mm/kasan/report.c:385 __kasan_report mm/kasan/report.c:545 [inline] kasan_report.cold+0x1f/0x37 mm/kasan/report.c:562 check_memory_region_inline mm/kasan/generic.c:186 [inline] check_memory_region+0x13d/0x180 mm/kasan/generic.c:192 memcpy+0x39/0x60 mm/kasan/common.c:106 memcpy include/linux/string.h:399 [inline] read_extent_buffer+0x114/0x150 fs/btrfs/extent_io.c:5674 btree_readpage_end_io_hook+0x7de/0x950 fs/btrfs/disk-io.c:641 end_bio_extent_readpage+0x4de/0x10c0 fs/btrfs/extent_io.c:2854 bio_endio+0x3d3/0x7a0 block/bio.c:1449 end_workqueue_fn+0x114/0x170 fs/btrfs/disk-io.c:1696 btrfs_work_helper+0x20a/0xd20 fs/btrfs/async-thread.c:318 process_one_work+0x933/0x15a0 kernel/workqueue.c:2269 worker_thread+0x64c/0x1120 kernel/workqueue.c:2415 kthread+0x3af/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296 addr ffffc90000dd79f0 is located in stack of task kworker/u4:1/21 at offset 48 in frame: btree_readpage_end_io_hook+0x0/0x950 fs/btrfs/disk-io.c:201 this frame has 4 objects: [48, 52) 'val' [64, 80) 'fsid' [96, 128) 'result' [160, 192) 'found' Memory state around the buggy address: ffffc90000dd7880: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffffc90000dd7900: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffffc90000dd7980: 00 00 00 00 00 00 00 00 f1 f1 f1 f1 f1 f1 04 f2 ^ ffffc90000dd7a00: 00 00 f2 f2 00 00 00 00 f2 f2 f2 f2 00 00 00 00 ffffc90000dd7a80: f3 f3 f3 f3 00 00 00 00 00 00 00 00 00 00 00 00 ================================================================== --- This report 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 syzkal...@googlegroups.com. syzbot will keep track of this issue. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot. syzbot can test patches for this issue, for details see: https://goo.gl/tpsmEJ#testing-patches
