================================================================== 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 ffff8880a41f9188 by task syz-executor1/24562 CPU: 1 PID: 24562 Comm: syz-executor1 Not tainted 5.0.0-rc4+ #48 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+0x26/0x50 kernel/kcov.c:101 Code: 90 90 90 90 55 48 89 e5 48 8b 75 08 65 48 8b 04 25 40 ee 01 00 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 RSP: 0018:ffff88805eabfa60 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13 RAX: ffff88805f06e240 RBX: 0000000000000000 RCX: ffffffff818ff03a RDX: 0000000000000000 RSI: ffffffff818ff048 RDI: 0000000000000007 RBP: ffff88805eabfa60 R08: ffff88805f06e240 R09: ffffed1015d25bc8 R10: ffffed1015d25bc7 R11: ffff8880ae92de3b R12: ffffea0001ed2f40 R13: ffffea0001ed2f48 R14: ffffea0001edd488 R15: ffff8880a33e3888 __read_once_size include/linux/compiler.h:193 [inline] compound_head include/linux/page-flags.h:143 [inline] PageActive include/linux/page-flags.h:290 [inline] mark_page_accessed+0x58/0x1140 mm/swap.c:379 touch_buffer fs/buffer.c:59 [inline] __find_get_block+0x312/0xcc0 fs/buffer.c:1298 sb_find_get_block include/linux/buffer_head.h:338 [inline] recently_deleted fs/ext4/ialloc.c:682 [inline] find_inode_bit.isra.0+0x202/0x510 fs/ext4/ialloc.c:722 __ext4_new_inode+0x14ad/0x52c0 fs/ext4/ialloc.c:914 ext4_symlink+0x3f8/0xbe0 fs/ext4/namei.c:3096 vfs_symlink fs/namei.c:4126 [inline] vfs_symlink+0x378/0x5d0 fs/namei.c:4112 do_symlinkat+0x22b/0x290 fs/namei.c:4153 __do_sys_symlink fs/namei.c:4172 [inline] __se_sys_symlink fs/namei.c:4170 [inline] __x64_sys_symlink+0x59/0x80 fs/namei.c:4170 do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457b67 Code: 0f 1f 00 b8 5c 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 6d bb fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 b8 58 00 00 00 0f 05 <48> 3d 01 f0 ff ff 0f 83 4d bb fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007ffdadc71758 EFLAGS: 00000202 ORIG_RAX: 0000000000000058 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000457b67 RDX: 00007ffdadc717d3 RSI: 00000000004bd63f RDI: 00007ffdadc717c0 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000013 R10: 0000000000000075 R11: 0000000000000202 R12: 0000000000000000 R13: 0000000000000001 R14: 000000000000000d R15: 0000000000000001 Allocated by task 24546: 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 2980: 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 ffff8880a41f9080 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 264 bytes inside of 512-byte region [ffff8880a41f9080, ffff8880a41f9280) The buggy address belongs to the page: page:ffffea0002907e40 count:1 mapcount:0 mapping:ffff88812c3f0940 index:0xffff8880a41f9580 flags: 0x1fffc0000000200(slab) raw: 01fffc0000000200 ffffea0002497b48 ffffea00028d1d48 ffff88812c3f0940 raw: ffff8880a41f9580 ffff8880a41f9080 0000000100000004 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8880a41f9080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880a41f9100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8880a41f9180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880a41f9200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880a41f9280: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================