================================================================== BUG: KASAN: use-after-free in btrfs_printk+0x38b/0x40c fs/btrfs/super.c:245 Read of size 8 at addr ffff8880190a86a0 by task systemd-udevd/11992 CPU: 0 PID: 11992 Comm: systemd-udevd Not tainted 5.10.0-rc2-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/0x497 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_control_ioctl+0x12a/0x2d0 fs/btrfs/super.c:2327 vfs_ioctl fs/ioctl.c:48 [inline] __do_sys_ioctl fs/ioctl.c:753 [inline] __se_sys_ioctl fs/ioctl.c:739 [inline] __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:739 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x7f90a896c017 Code: 00 00 00 48 8b 05 81 7e 2b 00 64 c7 00 26 00 00 00 48 c7 c0 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 b8 10 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 51 7e 2b 00 f7 d8 64 89 01 48 RSP: 002b:00007ffdf2fd37d8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f90a896c017 RDX: 00007ffdf2fd37f0 RSI: 0000000090009427 RDI: 000000000000000f RBP: 00007ffdf2fd37f0 R08: 0000000000000000 R09: 000000000000000d R10: fffffffffffffead R11: 0000000000000246 R12: 000000000000000f R13: 0000000000000000 R14: 00005633c2dc2510 R15: 00005633c2dadd70 Allocated by task 15296: kasan_save_stack+0x1b/0x40 mm/kasan/common.c:48 kasan_set_track mm/kasan/common.c:56 [inline] __kasan_kmalloc.constprop.0+0xbf/0xd0 mm/kasan/common.c:461 kmalloc_node include/linux/slab.h:575 [inline] kvmalloc_node+0xb4/0xf0 mm/util.c:575 kvmalloc include/linux/mm.h:765 [inline] kvzalloc include/linux/mm.h:773 [inline] btrfs_mount_root+0x117/0xbb0 fs/btrfs/super.c:1613 legacy_get_tree+0x105/0x220 fs/fs_context.c:592 vfs_get_tree+0x89/0x2f0 fs/super.c:1549 fc_mount fs/namespace.c:978 [inline] vfs_kern_mount.part.0+0xd3/0x170 fs/namespace.c:1008 vfs_kern_mount+0x3c/0x60 fs/namespace.c:995 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:2875 [inline] path_mount+0x13ad/0x20c0 fs/namespace.c:3205 do_mount fs/namespace.c:3218 [inline] __do_sys_mount fs/namespace.c:3426 [inline] __se_sys_mount fs/namespace.c:3403 [inline] __x64_sys_mount+0x27f/0x300 fs/namespace.c:3403 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Freed by task 15296: kasan_save_stack+0x1b/0x40 mm/kasan/common.c:48 kasan_set_track+0x1c/0x30 mm/kasan/common.c:56 kasan_set_free_info+0x1b/0x30 mm/kasan/generic.c:355 __kasan_slab_free+0xd8/0x120 mm/kasan/common.c:422 __cache_free mm/slab.c:3420 [inline] kfree+0xe8/0x240 mm/slab.c:3758 kvfree+0x42/0x50 mm/util.c:604 deactivate_locked_super+0x94/0x160 fs/super.c:335 btrfs_mount_root+0x772/0xbb0 fs/btrfs/super.c:1678 legacy_get_tree+0x105/0x220 fs/fs_context.c:592 vfs_get_tree+0x89/0x2f0 fs/super.c:1549 fc_mount fs/namespace.c:978 [inline] vfs_kern_mount.part.0+0xd3/0x170 fs/namespace.c:1008 vfs_kern_mount+0x3c/0x60 fs/namespace.c:995 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:2875 [inline] path_mount+0x13ad/0x20c0 fs/namespace.c:3205 do_mount fs/namespace.c:3218 [inline] __do_sys_mount fs/namespace.c:3426 [inline] __se_sys_mount fs/namespace.c:3403 [inline] __x64_sys_mount+0x27f/0x300 fs/namespace.c:3403 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 The buggy address belongs to the object at ffff8880190a8000 which belongs to the cache kmalloc-16k of size 16384 The buggy address is located 1696 bytes inside of 16384-byte region [ffff8880190a8000, ffff8880190ac000) The buggy address belongs to the page: page:00000000a7411533 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x190a8 head:00000000a7411533 order:3 compound_mapcount:0 compound_pincount:0 flags: 0xfff00000010200(slab|head) raw: 00fff00000010200 ffffea0000696c08 ffffea0000a1b408 ffff888010040b00 raw: 0000000000000000 ffff8880190a8000 0000000100000001 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8880190a8580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880190a8600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8880190a8680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880190a8700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880190a8780: fb fb fb fb fb fb fb fb fb fb fb fb fb 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