================================================================== BUG: KASAN: use-after-free in btrfs_printk+0x395/0x425 fs/btrfs/super.c:244 Read of size 8 at addr ffff8880239986d8 by task udevd/13278 CPU: 3 PID: 13278 Comm: udevd Not tainted 5.17.0-rc5-syzkaller-00306-g2293be58d6a1 #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.14.0-2 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 print_address_description.constprop.0.cold+0x8d/0x303 mm/kasan/report.c:255 __kasan_report mm/kasan/report.c:442 [inline] kasan_report.cold+0x83/0xdf mm/kasan/report.c:459 btrfs_printk+0x395/0x425 fs/btrfs/super.c:244 device_list_add.cold+0xd7/0x2ed fs/btrfs/volumes.c:957 btrfs_scan_one_device+0x4c7/0x5c0 fs/btrfs/volumes.c:1387 btrfs_control_ioctl+0x12a/0x2d0 fs/btrfs/super.c:2409 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:874 [inline] __se_sys_ioctl fs/ioctl.c:860 [inline] __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:860 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f90babe10e7 Code: 3c 1c e8 1c ff ff ff 85 c0 79 87 49 c7 c4 ff ff ff ff 5b 5d 4c 89 e0 41 5c c3 66 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 61 9d 0c 00 f7 d8 64 89 01 48 RSP: 002b:00007ffe924cccb8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f90babe10e7 RDX: 00007ffe924cccc8 RSI: 0000000090009427 RDI: 0000000000000009 RBP: 0000000000000009 R08: 00005597be8956f0 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffe924cdd08 R14: 00005597c08274c0 R15: 00007f90baa846c0 Allocated by task 27189: kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38 kasan_set_track mm/kasan/common.c:45 [inline] set_alloc_info mm/kasan/common.c:436 [inline] ____kasan_kmalloc mm/kasan/common.c:515 [inline] ____kasan_kmalloc mm/kasan/common.c:474 [inline] __kasan_kmalloc+0xa6/0xd0 mm/kasan/common.c:524 kmalloc_node include/linux/slab.h:604 [inline] kvmalloc_node+0x97/0x100 mm/util.c:580 kvmalloc include/linux/slab.h:731 [inline] kvzalloc include/linux/slab.h:739 [inline] btrfs_mount_root+0x118/0xc10 fs/btrfs/super.c:1665 legacy_get_tree+0x105/0x220 fs/fs_context.c:610 vfs_get_tree+0x89/0x2f0 fs/super.c:1497 fc_mount fs/namespace.c:1030 [inline] vfs_kern_mount.part.0+0xd3/0x170 fs/namespace.c:1060 vfs_kern_mount+0x3c/0x60 fs/namespace.c:1047 btrfs_mount+0x234/0xa60 fs/btrfs/super.c:1784 legacy_get_tree+0x105/0x220 fs/fs_context.c:610 vfs_get_tree+0x89/0x2f0 fs/super.c:1497 do_new_mount fs/namespace.c:3024 [inline] path_mount+0x1320/0x1fa0 fs/namespace.c:3354 do_mount fs/namespace.c:3367 [inline] __do_sys_mount fs/namespace.c:3575 [inline] __se_sys_mount fs/namespace.c:3552 [inline] __x64_sys_mount+0x27f/0x300 fs/namespace.c:3552 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae Freed by task 3695: kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38 kasan_set_track+0x21/0x30 mm/kasan/common.c:45 kasan_set_free_info+0x20/0x30 mm/kasan/generic.c:370 ____kasan_slab_free mm/kasan/common.c:366 [inline] ____kasan_slab_free+0xff/0x140 mm/kasan/common.c:328 kasan_slab_free include/linux/kasan.h:236 [inline] __cache_free mm/slab.c:3437 [inline] kfree+0xf8/0x2b0 mm/slab.c:3794 kvfree+0x42/0x50 mm/util.c:613 deactivate_locked_super+0x94/0x160 fs/super.c:332 deactivate_super+0xad/0xd0 fs/super.c:363 cleanup_mnt+0x3a2/0x540 fs/namespace.c:1173 task_work_run+0xdd/0x1a0 kernel/task_work.c:164 tracehook_notify_resume include/linux/tracehook.h:188 [inline] exit_to_user_mode_loop kernel/entry/common.c:175 [inline] exit_to_user_mode_prepare+0x27e/0x290 kernel/entry/common.c:207 __syscall_exit_to_user_mode_work kernel/entry/common.c:289 [inline] syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:300 do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x44/0xae The buggy address belongs to the object at ffff888023998000 which belongs to the cache kmalloc-16k of size 16384 The buggy address is located 1752 bytes inside of 16384-byte region [ffff888023998000, ffff88802399c000) The buggy address belongs to the page: page:ffffea00008e6600 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x23998 head:ffffea00008e6600 order:3 compound_mapcount:0 compound_pincount:0 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 ffffea0000ae8808 ffffea00008e2a08 ffff888010c40b00 raw: 0000000000000000 ffff888023998000 0000000100000001 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Unmovable, gfp_mask 0x2520c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_THISNODE), pid 27189, ts 829195597682, free_ts 820520477771 prep_new_page mm/page_alloc.c:2434 [inline] get_page_from_freelist+0xa72/0x2f50 mm/page_alloc.c:4165 __alloc_pages_slowpath.constprop.0+0x2eb/0x20d0 mm/page_alloc.c:4934 __alloc_pages+0x412/0x500 mm/page_alloc.c:5402 __alloc_pages_node include/linux/gfp.h:572 [inline] kmem_getpages mm/slab.c:1378 [inline] cache_grow_begin+0x75/0x390 mm/slab.c:2584 cache_alloc_refill+0x27f/0x380 mm/slab.c:2957 ____cache_alloc mm/slab.c:3040 [inline] ____cache_alloc mm/slab.c:3023 [inline] slab_alloc_node mm/slab.c:3241 [inline] kmem_cache_alloc_node_trace+0x49c/0x5b0 mm/slab.c:3609 __do_kmalloc_node mm/slab.c:3631 [inline] __kmalloc_node+0x38/0x60 mm/slab.c:3639 kmalloc_node include/linux/slab.h:604 [inline] kvmalloc_node+0x97/0x100 mm/util.c:580 kvmalloc include/linux/slab.h:731 [inline] kvzalloc include/linux/slab.h:739 [inline] btrfs_mount_root+0x118/0xc10 fs/btrfs/super.c:1665 legacy_get_tree+0x105/0x220 fs/fs_context.c:610 vfs_get_tree+0x89/0x2f0 fs/super.c:1497 fc_mount fs/namespace.c:1030 [inline] vfs_kern_mount.part.0+0xd3/0x170 fs/namespace.c:1060 vfs_kern_mount+0x3c/0x60 fs/namespace.c:1047 btrfs_mount+0x234/0xa60 fs/btrfs/super.c:1784 legacy_get_tree+0x105/0x220 fs/fs_context.c:610 vfs_get_tree+0x89/0x2f0 fs/super.c:1497 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1352 [inline] free_pcp_prepare+0x374/0x870 mm/page_alloc.c:1404 free_unref_page_prepare mm/page_alloc.c:3325 [inline] free_unref_page+0x19/0x690 mm/page_alloc.c:3404 slab_destroy mm/slab.c:1630 [inline] slabs_destroy+0x89/0xc0 mm/slab.c:1650 cache_flusharray mm/slab.c:3410 [inline] ___cache_free+0x303/0x600 mm/slab.c:3472 qlink_free mm/kasan/quarantine.c:157 [inline] qlist_free_all+0x50/0x1a0 mm/kasan/quarantine.c:176 kasan_quarantine_reduce+0x180/0x200 mm/kasan/quarantine.c:283 __kasan_slab_alloc+0x97/0xb0 mm/kasan/common.c:446 kasan_slab_alloc include/linux/kasan.h:260 [inline] slab_post_alloc_hook mm/slab.h:732 [inline] slab_alloc mm/slab.c:3315 [inline] kmem_cache_alloc+0x265/0x560 mm/slab.c:3499 getname_flags.part.0+0x50/0x4f0 fs/namei.c:138 getname_flags+0x9a/0xe0 include/linux/audit.h:323 user_path_at_empty+0x2b/0x60 fs/namei.c:2850 do_readlinkat+0xcd/0x2f0 fs/stat.c:443 __do_sys_readlink fs/stat.c:476 [inline] __se_sys_readlink fs/stat.c:473 [inline] __x64_sys_readlink+0x74/0xb0 fs/stat.c:473 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae Memory state around the buggy address: ffff888023998580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888023998600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888023998680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888023998700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888023998780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================