On Wed, 21 Aug 2019, syzbot wrote: > Hello, > > syzbot has tested the proposed patch but the reproducer still triggered > crash: > KASAN: slab-out-of-bounds Read in hidraw_ioctl > > ================================================================== > BUG: KASAN: slab-out-of-bounds in strlen+0x79/0x90 lib/string.c:525 > Read of size 1 at addr ffff8881c8035f38 by task syz-executor.4/2833 > > CPU: 1 PID: 2833 Comm: syz-executor.4 Not tainted 5.3.0-rc2+ #1 > 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+0xca/0x13e lib/dump_stack.c:113 > print_address_description+0x6a/0x32c mm/kasan/report.c:351 > __kasan_report.cold+0x1a/0x33 mm/kasan/report.c:482 > kasan_report+0xe/0x12 mm/kasan/common.c:612 > strlen+0x79/0x90 lib/string.c:525 > strlen include/linux/string.h:281 [inline] > hidraw_ioctl+0x245/0xae0 drivers/hid/hidraw.c:446 > vfs_ioctl fs/ioctl.c:46 [inline] > file_ioctl fs/ioctl.c:509 [inline] > do_vfs_ioctl+0xd2d/0x1330 fs/ioctl.c:696 > ksys_ioctl+0x9b/0xc0 fs/ioctl.c:713 > __do_sys_ioctl fs/ioctl.c:720 [inline] > __se_sys_ioctl fs/ioctl.c:718 [inline] > __x64_sys_ioctl+0x6f/0xb0 fs/ioctl.c:718 > do_syscall_64+0xb7/0x580 arch/x86/entry/common.c:296 > entry_SYSCALL_64_after_hwframe+0x49/0xbe > RIP: 0033:0x459829 > Code: fd b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 > 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff > ff 0f 83 cb b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 > RSP: 002b:00007f7a68f6dc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 > RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000459829 > RDX: 0000000000000000 RSI: 0000000080404805 RDI: 0000000000000004 > RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000 > R10: 0000000000000000 R11: 0000000000000246 R12: 00007f7a68f6e6d4 > R13: 00000000004c21de R14: 00000000004d5620 R15: 00000000ffffffff > > Allocated by task 0: > (stack is not available) > > Freed by task 0: > (stack is not available) > > The buggy address belongs to the object at ffff8881c8035e60 > which belongs to the cache shmem_inode_cache of size 1168 > The buggy address is located 216 bytes inside of > 1168-byte region [ffff8881c8035e60, ffff8881c80362f0) > The buggy address belongs to the page: > page:ffffea0007200d00 refcount:1 mapcount:0 mapping:ffff8881da115180 > index:0x0 compound_mapcount: 0 > flags: 0x200000000010200(slab|head) > raw: 0200000000010200 dead000000000100 dead000000000122 ffff8881da115180 > raw: 0000000000000000 00000000800c000c 00000001ffffffff 0000000000000000 > page dumped because: kasan: bad access detected > > Memory state around the buggy address: > ffff8881c8035e00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc > ffff8881c8035e80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc > > ffff8881c8035f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc > ^ > ffff8881c8035f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc > ffff8881c8036000: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc > ================================================================== > > > Tested on: > > commit: e96407b4 usb-fuzzer: main usb gadget fuzzer driver > git tree: https://github.com/google/kasan.git > console output: https://syzkaller.appspot.com/x/log.txt?x=14f14a1e600000 > kernel config: https://syzkaller.appspot.com/x/.config?x=cfa2c18fb6a8068e > compiler: gcc (GCC) 9.0.0 20181231 (experimental) > patch: https://syzkaller.appspot.com/x/patch.diff?x=171cd95a600000 Get some debugging info: #syz test: https://github.com/google/kasan.git e96407b4 Index: usb-devel/drivers/hid/hid-core.c =================================================================== --- usb-devel.orig/drivers/hid/hid-core.c +++ usb-devel/drivers/hid/hid-core.c @@ -1973,6 +1973,8 @@ int hid_hw_start(struct hid_device *hdev { int error; + dev_info(&hdev->dev, "In hid_hw_start for %p\n", hdev); + dump_stack(); error = hdev->ll_driver->start(hdev); if (error) return error; @@ -1998,6 +2000,7 @@ EXPORT_SYMBOL_GPL(hid_hw_start); */ void hid_hw_stop(struct hid_device *hdev) { + dev_info(&hdev->dev, "In hid_hw_stop for %p\n", hdev); hid_disconnect(hdev); hdev->ll_driver->stop(hdev); }
