================================================================== 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 ffff8880a6065888 by task syz-executor2/10847 CPU: 1 PID: 10847 Comm: syz-executor2 Not tainted 5.0.0-rc4+ #28 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:__sanitizer_cov_trace_pc+0x3b/0x50 kernel/kcov.c:106 Code: 65 8b 15 08 12 92 7e 81 e2 00 01 1f 00 75 2b 8b 90 d8 12 00 00 83 fa 02 75 20 48 8b 88 e0 12 00 00 8b 80 dc 12 00 00 48 8b 11 <48> 83 c2 01 48 39 d0 76 07 48 89 34 d1 48 89 11 5d c3 0f 1f 00 65 RSP: 0018:ffff88805fffed88 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13 RAX: 0000000000040000 RBX: ffffffff88a45200 RCX: ffffc9000a245000 RDX: 0000000000023d5a RSI: ffffffff833b6cdd RDI: 0000000000000007 RBP: ffff88805fffed88 R08: ffff88808bdaa3c0 R09: fffff94000445a9f R10: fffff94000445a9e R11: ffffea000222d4f7 R12: 1ffff1100bfffdb7 R13: 0000000000000000 R14: 0000000000000000 R15: ffff88805fffee18 should_fail+0x14d/0x85c lib/fault-inject.c:133 __should_failslab+0x121/0x190 mm/failslab.c:32 should_failslab+0x9/0x14 mm/slab_common.c:1603 slab_pre_alloc_hook mm/slab.h:423 [inline] slab_alloc mm/slab.c:3367 [inline] kmem_cache_alloc+0x2be/0x710 mm/slab.c:3541 ext4_mb_new_inode_pa+0x1b8/0x1400 fs/ext4/mballoc.c:3636 ext4_mb_new_preallocation fs/ext4/mballoc.c:3781 [inline] ext4_mb_new_blocks+0x3330/0x3c70 fs/ext4/mballoc.c:4547 ext4_alloc_branch fs/ext4/indirect.c:335 [inline] ext4_ind_map_blocks+0x16be/0x2560 fs/ext4/indirect.c:619 ext4_map_blocks+0xf52/0x1a20 fs/ext4/inode.c:638 _ext4_get_block+0x1e2/0x5c0 fs/ext4/inode.c:783 ext4_get_block_trans+0x17b/0x2b0 fs/ext4/inode.c:844 ext4_dio_get_block+0x78/0xc0 fs/ext4/inode.c:861 get_more_blocks fs/direct-io.c:717 [inline] do_direct_IO fs/direct-io.c:1002 [inline] do_blockdev_direct_IO+0x2689/0x8db0 fs/direct-io.c:1334 __blockdev_direct_IO+0xa1/0xca fs/direct-io.c:1420 ext4_direct_IO_write fs/ext4/inode.c:3775 [inline] ext4_direct_IO+0xe6c/0x1c10 fs/ext4/inode.c:3902 generic_file_direct_write+0x214/0x4b0 mm/filemap.c:3111 __generic_file_write_iter+0x2ee/0x630 mm/filemap.c:3290 ext4_file_write_iter+0x33f/0x1160 fs/ext4/file.c:266 call_write_iter include/linux/fs.h:1862 [inline] new_sync_write fs/read_write.c:474 [inline] __vfs_write+0x613/0x8e0 fs/read_write.c:487 vfs_write+0x20c/0x580 fs/read_write.c:549 ksys_write+0xea/0x1f0 fs/read_write.c:598 __do_sys_write fs/read_write.c:610 [inline] __se_sys_write fs/read_write.c:607 [inline] __x64_sys_write+0x73/0xb0 fs/read_write.c:607 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:00007fd6c26bec78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000457e39 RDX: 0000000020032600 RSI: 0000000020000000 RDI: 0000000000000006 RBP: 000000000073bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fd6c26bf6d4 R13: 00000000004c71ea R14: 00000000004dcc08 R15: 00000000ffffffff Allocated by task 10846: 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 7828: 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 ffff8880a6065780 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 264 bytes inside of 512-byte region [ffff8880a6065780, ffff8880a6065980) The buggy address belongs to the page: page:ffffea0002981940 count:1 mapcount:0 mapping:ffff88812c3f0940 index:0x0 flags: 0x1fffc0000000200(slab) raw: 01fffc0000000200 ffffea00026bf788 ffffea00028b1608 ffff88812c3f0940 raw: 0000000000000000 ffff8880a6065000 0000000100000006 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8880a6065780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880a6065800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8880a6065880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880a6065900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880a6065980: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================