================================================================== BUG: KASAN: use-after-free in dev_map_generic_redirect+0xa0/0x650 kernel/bpf/devmap.c:668 Read of size 8 at addr ffff888053dc9180 by task syz.1.1015/7600 CPU: 1 PID: 7600 Comm: syz.1.1015 Not tainted 6.1.127-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106 print_address_description mm/kasan/report.c:316 [inline] print_report+0x15f/0x4f0 mm/kasan/report.c:427 kasan_report+0x136/0x160 mm/kasan/report.c:531 dev_map_generic_redirect+0xa0/0x650 kernel/bpf/devmap.c:668 xdp_do_generic_redirect_map net/core/filter.c:4416 [inline] xdp_do_generic_redirect+0x4bf/0x850 net/core/filter.c:4475 do_xdp_generic+0x50b/0x6d0 net/core/dev.c:4957 tun_get_user+0x261e/0x42d0 drivers/net/tun.c:1920 tun_chr_write_iter+0x10c/0x1f0 drivers/net/tun.c:2044 call_write_iter include/linux/fs.h:2265 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x857/0xbc0 fs/read_write.c:584 ksys_write+0x19c/0x2c0 fs/read_write.c:637 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f14e618b85f Code: 89 54 24 18 48 89 74 24 10 89 7c 24 08 e8 f9 92 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 4c 93 02 00 48 RSP: 002b:00007f14e70ac000 EFLAGS: 00000293 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f14e63a5fa0 RCX: 00007f14e618b85f RDX: 000000000000fe53 RSI: 0000000020000440 RDI: 00000000000000c8 RBP: 00007f14e620e2a0 R08: 0000000000000000 R09: 0000000000000000 R10: 000000000000fe53 R11: 0000000000000293 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f14e63a5fa0 R15: 00007ffee1c46198 Allocated by task 5273: kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:52 ____kasan_kmalloc mm/kasan/common.c:374 [inline] __kasan_kmalloc+0x97/0xb0 mm/kasan/common.c:383 kasan_kmalloc include/linux/kasan.h:211 [inline] __do_kmalloc_node mm/slab_common.c:936 [inline] __kmalloc_node+0xb3/0x230 mm/slab_common.c:943 kmalloc_node include/linux/slab.h:589 [inline] kvmalloc_node+0x6e/0x180 mm/util.c:581 kvmalloc include/linux/slab.h:716 [inline] alloc_fdtable+0x154/0x280 fs/file.c:138 dup_fd+0x95c/0xca0 fs/file.c:337 copy_files+0x72/0xe0 kernel/fork.c:1636 copy_process+0x1873/0x4060 kernel/fork.c:2254 kernel_clone+0x222/0x920 kernel/fork.c:2681 __do_sys_clone kernel/fork.c:2822 [inline] __se_sys_clone kernel/fork.c:2806 [inline] __x64_sys_clone+0x231/0x280 kernel/fork.c:2806 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 The buggy address belongs to the object at ffff888053dc9180 which belongs to the cache kmalloc-cg-96 of size 96 The buggy address is located 0 bytes inside of 96-byte region [ffff888053dc9180, ffff888053dc91e0) The buggy address belongs to the physical page: page:ffffea00014f7240 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff888053dc9e80 pfn:0x53dc9 memcg:ffff88807a2eb401 flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000000200 ffffea0001d01d80 dead000000000002 ffff888017c428c0 raw: ffff888053dc9e80 000000008020000b 00000001ffffffff ffff88807a2eb401 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 4250, tgid 4250 (syz-executor), ts 88221135287, free_ts 87296880925 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x18d/0x1b0 mm/page_alloc.c:2532 prep_new_page mm/page_alloc.c:2539 [inline] get_page_from_freelist+0x3731/0x38d0 mm/page_alloc.c:4328 __alloc_pages+0x28d/0x770 mm/page_alloc.c:5605 alloc_slab_page+0x6a/0x150 mm/slub.c:1794 allocate_slab mm/slub.c:1939 [inline] new_slab+0x84/0x2d0 mm/slub.c:1992 ___slab_alloc+0xc20/0x1270 mm/slub.c:3180 __slab_alloc mm/slub.c:3279 [inline] slab_alloc_node mm/slub.c:3364 [inline] __kmem_cache_alloc_node+0x19f/0x260 mm/slub.c:3437 __do_kmalloc_node mm/slab_common.c:935 [inline] __kmalloc_node+0xa2/0x230 mm/slab_common.c:943 kmalloc_node include/linux/slab.h:589 [inline] kvmalloc_node+0x6e/0x180 mm/util.c:581 kvmalloc include/linux/slab.h:716 [inline] alloc_fdtable+0x154/0x280 fs/file.c:138 dup_fd+0x95c/0xca0 fs/file.c:337 copy_files+0x72/0xe0 kernel/fork.c:1636 copy_process+0x1873/0x4060 kernel/fork.c:2254 kernel_clone+0x222/0x920 kernel/fork.c:2681 __do_sys_clone kernel/fork.c:2822 [inline] __se_sys_clone kernel/fork.c:2806 [inline] __x64_sys_clone+0x231/0x280 kernel/fork.c:2806 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1459 [inline] free_pcp_prepare mm/page_alloc.c:1509 [inline] free_unref_page_prepare+0x12a6/0x15b0 mm/page_alloc.c:3384 free_unref_page_list+0x663/0x900 mm/page_alloc.c:3525 release_pages+0x24c4/0x27a0 mm/swap.c:1035 tlb_batch_pages_flush mm/mmu_gather.c:59 [inline] tlb_flush_mmu_free mm/mmu_gather.c:254 [inline] tlb_flush_mmu+0xfc/0x210 mm/mmu_gather.c:261 tlb_finish_mmu+0xce/0x1f0 mm/mmu_gather.c:361 exit_mmap+0x3b3/0x980 mm/mmap.c:3250 __mmput+0x115/0x3c0 kernel/fork.c:1200 exit_mm+0x226/0x300 kernel/exit.c:565 do_exit+0x9f1/0x26a0 kernel/exit.c:858 do_group_exit+0x202/0x2b0 kernel/exit.c:1021 get_signal+0x16f7/0x17d0 kernel/signal.c:2871 arch_do_signal_or_restart+0xb0/0x1a10 arch/x86/kernel/signal.c:871 exit_to_user_mode_loop+0x6a/0x100 kernel/entry/common.c:174 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline] syscall_exit_to_user_mode+0x60/0x270 kernel/entry/common.c:303 do_syscall_64+0x47/0xb0 arch/x86/entry/common.c:87 Memory state around the buggy address: ffff888053dc9080: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ffff888053dc9100: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc >ffff888053dc9180: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ^ ffff888053dc9200: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ffff888053dc9280: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ==================================================================