================================================================== BUG: KASAN: use-after-free in btrfs_printk+0x38b/0x40c fs/btrfs/super.c:245 Read of size 8 at addr ffff88801bdec6a0 by task syz-executor473/11692 CPU: 0 PID: 11692 Comm: syz-executor473 Not tainted 5.10.0-rc1-next-20201030-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+0x107/0x163 lib/dump_stack.c:118 print_address_description.constprop.0.cold+0xae/0x4c8 mm/kasan/report.c:385 __kasan_report mm/kasan/report.c:545 [inline] kasan_report.cold+0x1f/0x37 mm/kasan/report.c:562 btrfs_printk+0x38b/0x40c fs/btrfs/super.c:245 device_list_add.cold+0x99/0x31e fs/btrfs/volumes.c:943 btrfs_scan_one_device+0x339/0x4a0 fs/btrfs/volumes.c:1366 btrfs_mount_root+0x4d5/0xbb0 fs/btrfs/super.c:1634 legacy_get_tree+0x105/0x220 fs/fs_context.c:592 vfs_get_tree+0x89/0x2f0 fs/super.c:1549 fc_mount fs/namespace.c:983 [inline] vfs_kern_mount.part.0+0xd3/0x170 fs/namespace.c:1013 vfs_kern_mount+0x3c/0x60 fs/namespace.c:1000 btrfs_mount+0x234/0xa60 fs/btrfs/super.c:1732 legacy_get_tree+0x105/0x220 fs/fs_context.c:592 vfs_get_tree+0x89/0x2f0 fs/super.c:1549 do_new_mount fs/namespace.c:2896 [inline] path_mount+0x12ae/0x1e70 fs/namespace.c:3227 do_mount fs/namespace.c:3240 [inline] __do_sys_mount fs/namespace.c:3448 [inline] __se_sys_mount fs/namespace.c:3425 [inline] __x64_sys_mount+0x27f/0x300 fs/namespace.c:3425 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x44ee3a Code: b8 08 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 bd 9f fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 0f 83 9a 9f fb ff c3 66 0f 1f 84 00 00 00 00 00 RSP: 002b:00007fd06f5d9be8 EFLAGS: 00000293 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 000000000044ee3a RDX: 0000000020000000 RSI: 0000000020000100 RDI: 00007fd06f5d9c10 RBP: 00007fd06f5d9c10 R08: 00007fd06f5d9c50 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000030 R13: 00007fd06f5d9c50 R14: 00007fd06f5da6d0 R15: 0000000000000003 The buggy address belongs to the page: page:00000000cc5b23bc refcount:0 mapcount:-128 mapping:0000000000000000 index:0x0 pfn:0x1bdec flags: 0xfff00000000000() raw: 00fff00000000000 ffff88813fffb910 ffffea0000460c08 0000000000000000 raw: 0000000000000000 0000000000000002 00000000ffffff7f 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88801bdec580: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff88801bdec600: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff >ffff88801bdec680: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ^ ffff88801bdec700: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff88801bdec780: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ==================================================================