================================================================== BUG: KASAN: slab-use-after-free in dev_map_generic_redirect+0x554/0x5f0 kernel/bpf/devmap.c:681 Read of size 8 at addr ffff88802a267a80 by task syz-executor.1/8875 CPU: 2 PID: 8875 Comm: syz-executor.1 Not tainted 6.9.0-rc2-syzkaller-00435-g9fe30842a90b #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:114 print_address_description mm/kasan/report.c:377 [inline] print_report+0xc3/0x620 mm/kasan/report.c:488 kasan_report+0xd9/0x110 mm/kasan/report.c:601 dev_map_generic_redirect+0x554/0x5f0 kernel/bpf/devmap.c:681 xdp_do_generic_redirect_map net/core/filter.c:4463 [inline] xdp_do_generic_redirect+0x2e8/0x700 net/core/filter.c:4520 do_xdp_generic+0x77f/0xc30 net/core/dev.c:5021 tun_get_user+0x1d01/0x3bf0 drivers/net/tun.c:1924 tun_chr_write_iter+0xe8/0x210 drivers/net/tun.c:2048 call_write_iter include/linux/fs.h:2110 [inline] new_sync_write fs/read_write.c:497 [inline] vfs_write+0x6db/0x1100 fs/read_write.c:590 ksys_write+0x12f/0x260 fs/read_write.c:643 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xd2/0x260 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x72/0x7a RIP: 0033:0x7fa2b507cbaf Code: 89 54 24 18 48 89 74 24 10 89 7c 24 08 e8 b9 80 02 00 48 8b 54 24 18 48 8b 74 24 10 41 89 c0 8b 7c 24 08 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 31 44 89 c7 48 89 44 24 08 e8 0c 81 02 00 48 RSP: 002b:00007fa2b5e44090 EFLAGS: 00000293 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007fa2b51abf80 RCX: 00007fa2b507cbaf RDX: 000000000000fdef RSI: 00000000200003c0 RDI: 00000000000000c8 RBP: 00007fa2b50ca47a R08: 0000000000000000 R09: 0000000000000000 R10: 000000000000fdef R11: 0000000000000293 R12: 0000000000000000 R13: 000000000000000b R14: 00007fa2b51abf80 R15: 00007ffd44844478 Allocated by task 5216: kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:370 [inline] __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:387 kmalloc include/linux/slab.h:628 [inline] alloc_fdtable+0xa0/0x290 fs/file.c:132 dup_fd+0x77d/0xc70 fs/file.c:354 copy_files kernel/fork.c:1791 [inline] copy_process+0x28bd/0x9160 kernel/fork.c:2377 kernel_clone+0xfd/0x980 kernel/fork.c:2796 __do_sys_clone+0xba/0x100 kernel/fork.c:2939 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xd2/0x260 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x72/0x7a Freed by task 8506: kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:579 poison_slab_object mm/kasan/common.c:240 [inline] __kasan_slab_free+0x11d/0x1a0 mm/kasan/common.c:256 kasan_slab_free include/linux/kasan.h:184 [inline] slab_free_hook mm/slub.c:2106 [inline] slab_free mm/slub.c:4280 [inline] kfree+0x129/0x390 mm/slub.c:4390 __free_fdtable fs/file.c:38 [inline] put_files_struct fs/file.c:451 [inline] put_files_struct+0x2b6/0x360 fs/file.c:444 exit_files+0x82/0xb0 fs/file.c:464 do_exit+0xa49/0x2c10 kernel/exit.c:873 do_group_exit+0xd3/0x2a0 kernel/exit.c:1027 get_signal+0x2616/0x2710 kernel/signal.c:2911 arch_do_signal_or_restart+0x90/0x7e0 arch/x86/kernel/signal.c:310 exit_to_user_mode_loop kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0x14a/0x2a0 kernel/entry/common.c:218 do_syscall_64+0xe2/0x260 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x72/0x7a The buggy address belongs to the object at ffff88802a267a80 which belongs to the cache kmalloc-cg-64 of size 64 The buggy address is located 0 bytes inside of freed 64-byte region [ffff88802a267a80, ffff88802a267ac0) The buggy address belongs to the physical page: page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x2a267 memcg:ffff8880125f3801 flags: 0xfff80000000800(slab|node=0|zone=1|lastcpupid=0xfff) page_type: 0xffffffff() raw: 00fff80000000800 ffff88801544d7c0 ffffea0001215b00 0000000000000002 raw: 0000000000000000 0000000080200020 00000001ffffffff ffff8880125f3801 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 0, migratetype Unmovable, gfp_mask 0x112cc0(GFP_USER|__GFP_NOWARN|__GFP_NORETRY), pid 5343, tgid 5342 (syz-executor.2), ts 57656736361, free_ts 57651252374 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x2d4/0x350 mm/page_alloc.c:1534 prep_new_page mm/page_alloc.c:1541 [inline] get_page_from_freelist+0xa28/0x3780 mm/page_alloc.c:3317 __alloc_pages+0x22b/0x2460 mm/page_alloc.c:4575 __alloc_pages_node include/linux/gfp.h:238 [inline] alloc_pages_node include/linux/gfp.h:261 [inline] alloc_slab_page mm/slub.c:2175 [inline] allocate_slab mm/slub.c:2338 [inline] new_slab+0xcc/0x3a0 mm/slub.c:2391 ___slab_alloc+0x66d/0x1790 mm/slub.c:3525 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3610 __slab_alloc_node mm/slub.c:3663 [inline] slab_alloc_node mm/slub.c:3835 [inline] kmalloc_trace+0x2fb/0x330 mm/slub.c:3992 kmalloc include/linux/slab.h:628 [inline] kzalloc include/linux/slab.h:749 [inline] kvm_set_irq_routing+0x252/0x9a0 arch/x86/kvm/../../../virt/kvm/irqchip.c:197 kvm_arch_vm_ioctl+0x9a1/0x1c70 arch/x86/kvm/x86.c:7050 kvm_vm_ioctl+0x1afe/0x3e20 arch/x86/kvm/../../../virt/kvm/kvm_main.c:5348 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:904 [inline] __se_sys_ioctl fs/ioctl.c:890 [inline] __x64_sys_ioctl+0x193/0x220 fs/ioctl.c:890 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xd2/0x260 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x72/0x7a page last free pid 1151 tgid 1151 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1141 [inline] free_unref_page_prepare+0x527/0xb10 mm/page_alloc.c:2347 free_unref_page+0x33/0x3c0 mm/page_alloc.c:2487 skb_free_frag include/linux/skbuff.h:3336 [inline] skb_free_head+0xa6/0x1e0 net/core/skbuff.c:1106 skb_release_data+0x76c/0x990 net/core/skbuff.c:1136 skb_release_all net/core/skbuff.c:1202 [inline] napi_consume_skb+0x15c/0x2b0 net/core/skbuff.c:1512 skb_defer_free_flush net/core/dev.c:6180 [inline] skb_defer_free_flush net/core/dev.c:6164 [inline] net_rx_action+0x3f1/0xf10 net/core/dev.c:6797 __do_softirq+0x218/0x922 kernel/softirq.c:554 Memory state around the buggy address: ffff88802a267980: 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc fc ffff88802a267a00: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc >ffff88802a267a80: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ^ ffff88802a267b00: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ffff88802a267b80: 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc fc 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