================================================================== BUG: KASAN: use-after-free in dev_map_flush_old kernel/bpf/devmap.c:389 [inline] BUG: KASAN: use-after-free in __dev_map_entry_free+0x2a9/0x330 kernel/bpf/devmap.c:403 Read of size 8 at addr ffff888092c09608 by task syz-executor.0/18712 CPU: 0 PID: 18712 Comm: syz-executor.0 Not tainted 5.0.0-rc4+ #31 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+0x172/0x1f0 lib/dump_stack.c:113 print_address_description.cold+0x7c/0x20d mm/kasan/report.c:187 kasan_report.cold+0x1b/0x40 mm/kasan/report.c:317 __asan_report_load8_noabort+0x14/0x20 mm/kasan/generic_report.c:135 dev_map_flush_old kernel/bpf/devmap.c:389 [inline] __dev_map_entry_free+0x2a9/0x330 kernel/bpf/devmap.c:403 __rcu_reclaim kernel/rcu/rcu.h:240 [inline] rcu_do_batch kernel/rcu/tree.c:2452 [inline] invoke_rcu_callbacks kernel/rcu/tree.c:2773 [inline] rcu_process_callbacks+0x928/0x1390 kernel/rcu/tree.c:2754 __do_softirq+0x266/0x95a kernel/softirq.c:292 invoke_softirq kernel/softirq.c:373 [inline] irq_exit+0x180/0x1d0 kernel/softirq.c:413 exiting_irq arch/x86/include/asm/apic.h:536 [inline] smp_apic_timer_interrupt+0x14a/0x570 arch/x86/kernel/apic/apic.c:1062 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:807 RIP: 0010:__read_once_size include/linux/compiler.h:193 [inline] RIP: 0010:trace_block_dirty_buffer include/trace/events/block.h:58 [inline] RIP: 0010:mark_buffer_dirty+0x3d6/0x660 fs/buffer.c:1088 Code: 5e 41 5f 5d c3 e8 0a ce b1 ff 65 ff 05 23 e0 43 7e 48 c7 c0 48 4c 5a 89 48 ba 00 00 00 00 00 fc ff df 48 c1 e8 03 80 3c 10 00 <0f> 85 26 02 00 00 48 8b 05 75 3e 9c 07 e8 78 19 9f ff 31 ff 41 89 RSP: 0018:ffff8880669ff748 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13 RAX: 1ffffffff12b4989 RBX: ffff88808e5a1dc8 RCX: ffffc90005e13000 RDX: dffffc0000000000 RSI: ffffffff81be0da6 RDI: 0000000000000001 RBP: ffff8880669ff770 R08: ffff888091110180 R09: ffffed101098a354 R10: ffffed101098a353 R11: ffff888084c51a9b R12: 0000000000000001 R13: 0000000000000000 R14: 0000000000000000 R15: ffff888084c516f0 __ext4_handle_dirty_metadata+0x37c/0x570 fs/ext4/ext4_jbd2.c:298 ext4_do_update_inode fs/ext4/inode.c:5345 [inline] ext4_mark_iloc_dirty+0x1734/0x2cb0 fs/ext4/inode.c:5875 ext4_mark_inode_dirty+0x23c/0x940 fs/ext4/inode.c:6054 ext4_alloc_file_blocks+0x468/0x9e0 fs/ext4/extents.c:4617 ext4_fallocate+0x91c/0x1fa0 fs/ext4/extents.c:4878 vfs_fallocate+0x4ac/0xa50 fs/open.c:308 ioctl_preallocate+0x197/0x210 fs/ioctl.c:490 file_ioctl fs/ioctl.c:506 [inline] do_vfs_ioctl+0x1185/0x1390 fs/ioctl.c:696 ksys_ioctl+0xab/0xd0 fs/ioctl.c:713 __do_sys_ioctl fs/ioctl.c:720 [inline] __se_sys_ioctl fs/ioctl.c:718 [inline] __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:718 do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457e39 Code: ad b8 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 7b b8 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fa0a8e23c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000457e39 RDX: 0000000020000000 RSI: 000000004030582a RDI: 0000000000000004 RBP: 000000000073bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fa0a8e246d4 R13: 00000000004c1308 R14: 00000000004d31a8 R15: 00000000ffffffff Allocated by task 18715: save_stack+0x45/0xd0 mm/kasan/common.c:73 set_track mm/kasan/common.c:85 [inline] __kasan_kmalloc mm/kasan/common.c:496 [inline] __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:469 kasan_kmalloc+0x9/0x10 mm/kasan/common.c:504 kmem_cache_alloc_trace+0x151/0x760 mm/slab.c:3609 kmalloc include/linux/slab.h:545 [inline] kzalloc include/linux/slab.h:740 [inline] dev_map_alloc kernel/bpf/devmap.c:102 [inline] dev_map_alloc+0x1be/0x6e0 kernel/bpf/devmap.c:88 find_and_alloc_map kernel/bpf/syscall.c:129 [inline] map_create kernel/bpf/syscall.c:526 [inline] __do_sys_bpf+0x97b/0x3ea0 kernel/bpf/syscall.c:2642 __se_sys_bpf kernel/bpf/syscall.c:2619 [inline] __x64_sys_bpf+0x73/0xb0 kernel/bpf/syscall.c:2619 do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 22: save_stack+0x45/0xd0 mm/kasan/common.c:73 set_track mm/kasan/common.c:85 [inline] __kasan_slab_free+0x102/0x150 mm/kasan/common.c:458 kasan_slab_free+0xe/0x10 mm/kasan/common.c:466 __cache_free mm/slab.c:3487 [inline] kfree+0xcf/0x230 mm/slab.c:3806 dev_map_free+0x43c/0x540 kernel/bpf/devmap.c:192 bpf_map_free_deferred+0xba/0xf0 kernel/bpf/syscall.c:290 process_one_work+0x98e/0x1760 kernel/workqueue.c:2153 worker_thread+0x98/0xe40 kernel/workqueue.c:2296 kthread+0x357/0x430 kernel/kthread.c:246 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352 The buggy address belongs to the object at ffff888092c09500 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 264 bytes inside of 512-byte region [ffff888092c09500, ffff888092c09700) The buggy address belongs to the page: page:ffffea00024b0240 count:1 mapcount:0 mapping:ffff88812c3f0940 index:0x0 flags: 0x1fffc0000000200(slab) raw: 01fffc0000000200 ffffea0002811888 ffffea00028fea48 ffff88812c3f0940 raw: 0000000000000000 ffff888092c09000 0000000100000006 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff888092c09500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888092c09580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888092c09600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888092c09680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888092c09700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================