================================================================== BUG: KASAN: slab-use-after-free in dev_map_generic_redirect+0x554/0x5f0 kernel/bpf/devmap.c:681 Read of size 8 at addr ffff88803d49e100 by task syz-executor.1/31303 CPU: 3 PID: 31303 Comm: syz-executor.1 Not tainted 6.9.0-rc3-syzkaller-00073-ge8c39d0f57f3 #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+0x1d13/0x3c00 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+0xcf/0x260 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f72fae7cbaf 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:00007f72fbc5b090 EFLAGS: 00000293 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f72fafabf80 RCX: 00007f72fae7cbaf RDX: 000000000000fdef RSI: 00000000200003c0 RDI: 00000000000000c8 RBP: 00007f72faeca47a R08: 0000000000000000 R09: 0000000000000000 R10: 000000000000fdef R11: 0000000000000293 R12: 0000000000000000 R13: 000000000000000b R14: 00007f72fafabf80 R15: 00007ffd2ed278a8 Allocated by task 27785: 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+0xcf/0x260 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 30760: 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+0xdc/0x260 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff88803d49e100 which belongs to the cache kmalloc-cg-64 of size 64 The buggy address is located 0 bytes inside of freed 64-byte region [ffff88803d49e100, ffff88803d49e140) The buggy address belongs to the physical page: page: refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88803d49eb80 pfn:0x3d49e memcg:ffff88805a008001 flags: 0xfff80000000800(slab|node=0|zone=1|lastcpupid=0xfff) page_type: 0xffffffff() raw: 00fff80000000800 ffff88801504d7c0 ffffea0000a1bac0 dead000000000006 raw: ffff88803d49eb80 0000000000200004 00000001ffffffff ffff88805a008001 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 20301, tgid 20301 (syz-executor.0), ts 420429644914, free_ts 418194503113 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] 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+0xcf/0x260 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f page last free pid 20234 tgid 20234 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 __put_partials+0x14c/0x170 mm/slub.c:2906 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x4e/0x140 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x192/0x1e0 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:322 kasan_slab_alloc include/linux/kasan.h:201 [inline] slab_post_alloc_hook mm/slub.c:3798 [inline] slab_alloc_node mm/slub.c:3845 [inline] kmem_cache_alloc+0x136/0x320 mm/slub.c:3852 getname_flags.part.0+0x50/0x4f0 fs/namei.c:139 getname_flags include/linux/audit.h:322 [inline] getname+0x8f/0xe0 fs/namei.c:218 do_sys_openat2+0x104/0x1e0 fs/open.c:1400 do_sys_open fs/open.c:1421 [inline] __do_sys_openat fs/open.c:1437 [inline] __se_sys_openat fs/open.c:1432 [inline] __x64_sys_openat+0x175/0x210 fs/open.c:1432 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcf/0x260 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f Memory state around the buggy address: ffff88803d49e000: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ffff88803d49e080: 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc fc >ffff88803d49e100: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ^ ffff88803d49e180: 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc fc ffff88803d49e200: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ==================================================================