On 21/09/2020 07:38, syzbot wrote: > syzbot has found a reproducer for the following issue on: > > HEAD commit: 325d0eab Merge branch 'akpm' (patches from Andrew) > git tree: upstream > console output: https://syzkaller.appspot.com/x/log.txt?x=1512df53900000 > kernel config: https://syzkaller.appspot.com/x/.config?x=6a8a2ae52ed737db > dashboard link: https://syzkaller.appspot.com/bug?extid=582e66e5edf36a22c7b0 > compiler: clang version 10.0.0 (https://github.com/llvm/llvm-project/ > c2443155a0fb245c8f17f2c1c72b6ea391e86e81) > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=12366f8b900000 > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=14e6929b900000 > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > Reported-by: syzbot+582e66e5edf36a22c...@syzkaller.appspotmail.com > > ================================================================== > BUG: KASAN: use-after-free in btrfs_printk+0x3eb/0x435 fs/btrfs/super.c:245 > Read of size 8 at addr ffff8880878e06a8 by task syz-executor225/7068 > > CPU: 1 PID: 7068 Comm: syz-executor225 Not tainted 5.9.0-rc5-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+0x1d6/0x29e lib/dump_stack.c:118 > print_address_description+0x66/0x620 mm/kasan/report.c:383 > __kasan_report mm/kasan/report.c:513 [inline] > kasan_report+0x132/0x1d0 mm/kasan/report.c:530 > btrfs_printk+0x3eb/0x435 fs/btrfs/super.c:245 > device_list_add+0x1a88/0x1d60 fs/btrfs/volumes.c:943 > btrfs_scan_one_device+0x196/0x490 fs/btrfs/volumes.c:1359 > btrfs_mount_root+0x48f/0xb60 fs/btrfs/super.c:1634 > legacy_get_tree+0xea/0x180 fs/fs_context.c:592 > vfs_get_tree+0x88/0x270 fs/super.c:1547 > fc_mount fs/namespace.c:978 [inline] > vfs_kern_mount+0xc9/0x160 fs/namespace.c:1008 > btrfs_mount+0x33c/0xae0 fs/btrfs/super.c:1732 > legacy_get_tree+0xea/0x180 fs/fs_context.c:592 > vfs_get_tree+0x88/0x270 fs/super.c:1547 > do_new_mount fs/namespace.c:2875 [inline] > path_mount+0x179d/0x29e0 fs/namespace.c:3192 > do_mount fs/namespace.c:3205 [inline] > __do_sys_mount fs/namespace.c:3413 [inline] > __se_sys_mount+0x126/0x180 fs/namespace.c:3390 > do_syscall_64+0x31/0x70 arch/x86/entry/common.c:46 > entry_SYSCALL_64_after_hwframe+0x44/0xa9 > RIP: 0033:0x44840a > Code: b8 08 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 cd a2 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 aa a2 fb ff c3 66 0f 1f 84 00 00 00 00 00 > RSP: 002b:00007ffedfffd608 EFLAGS: 00000293 ORIG_RAX: 00000000000000a5 > RAX: ffffffffffffffda RBX: 00007ffedfffd670 RCX: 000000000044840a > RDX: 0000000020000000 RSI: 0000000020000100 RDI: 00007ffedfffd630 > RBP: 00007ffedfffd630 R08: 00007ffedfffd670 R09: 0000000000000000 > R10: 0000000000000000 R11: 0000000000000293 R12: 000000000000001a > R13: 0000000000000004 R14: 0000000000000003 R15: 0000000000000003 > > Allocated by task 6945: > kasan_save_stack mm/kasan/common.c:48 [inline] > kasan_set_track mm/kasan/common.c:56 [inline] > __kasan_kmalloc+0x100/0x130 mm/kasan/common.c:461 > kmalloc_node include/linux/slab.h:577 [inline] > kvmalloc_node+0x81/0x110 mm/util.c:574 > kvmalloc include/linux/mm.h:757 [inline] > kvzalloc include/linux/mm.h:765 [inline] > btrfs_mount_root+0xd0/0xb60 fs/btrfs/super.c:1613 > legacy_get_tree+0xea/0x180 fs/fs_context.c:592 > vfs_get_tree+0x88/0x270 fs/super.c:1547 > fc_mount fs/namespace.c:978 [inline] > vfs_kern_mount+0xc9/0x160 fs/namespace.c:1008 > btrfs_mount+0x33c/0xae0 fs/btrfs/super.c:1732 > legacy_get_tree+0xea/0x180 fs/fs_context.c:592 > vfs_get_tree+0x88/0x270 fs/super.c:1547 > do_new_mount fs/namespace.c:2875 [inline] > path_mount+0x179d/0x29e0 fs/namespace.c:3192 > do_mount fs/namespace.c:3205 [inline] > __do_sys_mount fs/namespace.c:3413 [inline] > __se_sys_mount+0x126/0x180 fs/namespace.c:3390 > do_syscall_64+0x31/0x70 arch/x86/entry/common.c:46 > entry_SYSCALL_64_after_hwframe+0x44/0xa9 > > Freed by task 6945: > kasan_save_stack mm/kasan/common.c:48 [inline] > kasan_set_track+0x3d/0x70 mm/kasan/common.c:56 > kasan_set_free_info+0x17/0x30 mm/kasan/generic.c:355 > __kasan_slab_free+0xdd/0x110 mm/kasan/common.c:422 > __cache_free mm/slab.c:3418 [inline] > kfree+0x113/0x200 mm/slab.c:3756 > deactivate_locked_super+0xa7/0xf0 fs/super.c:335 > btrfs_mount_root+0x72b/0xb60 fs/btrfs/super.c:1678 > legacy_get_tree+0xea/0x180 fs/fs_context.c:592 > vfs_get_tree+0x88/0x270 fs/super.c:1547 > fc_mount fs/namespace.c:978 [inline] > vfs_kern_mount+0xc9/0x160 fs/namespace.c:1008 > btrfs_mount+0x33c/0xae0 fs/btrfs/super.c:1732 > legacy_get_tree+0xea/0x180 fs/fs_context.c:592 > vfs_get_tree+0x88/0x270 fs/super.c:1547 > do_new_mount fs/namespace.c:2875 [inline] > path_mount+0x179d/0x29e0 fs/namespace.c:3192 > do_mount fs/namespace.c:3205 [inline] > __do_sys_mount fs/namespace.c:3413 [inline] > __se_sys_mount+0x126/0x180 fs/namespace.c:3390 > do_syscall_64+0x31/0x70 arch/x86/entry/common.c:46 > entry_SYSCALL_64_after_hwframe+0x44/0xa9 > > The buggy address belongs to the object at ffff8880878e0000 > which belongs to the cache kmalloc-16k of size 16384 > The buggy address is located 1704 bytes inside of > 16384-byte region [ffff8880878e0000, ffff8880878e4000) > The buggy address belongs to the page: > page:0000000060704f30 refcount:1 mapcount:0 mapping:0000000000000000 > index:0x0 pfn:0x878e0 > head:0000000060704f30 order:3 compound_mapcount:0 compound_pincount:0 > flags: 0xfffe0000010200(slab|head) > raw: 00fffe0000010200 ffffea00028e9a08 ffffea00021e3608 ffff8880aa440b00 > raw: 0000000000000000 ffff8880878e0000 0000000100000001 0000000000000000 > page dumped because: kasan: bad access detected > > Memory state around the buggy address: > ffff8880878e0580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > ffff8880878e0600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >> ffff8880878e0680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > ^ > ffff8880878e0700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > ffff8880878e0780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > ================================================================== > >
#syz test: btrfs: Fix missing close devices
