================================================================== BUG: KASAN: slab-use-after-free in xsk_bind+0xe38/0xeac net/xdp/xsk.c:1758 Read of size 4 at addr ffff0000f15b298c by task syz.0.13/4945 CPU: 0 UID: 0 PID: 4945 Comm: syz.0.13 Not tainted syzkaller #0 PREEMPT Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/02/2026 Call trace: show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:499 (C) __dump_stack+0x30/0x40 lib/dump_stack.c:94 dump_stack_lvl+0xd8/0x12c lib/dump_stack.c:120 print_address_description+0xb0/0x238 mm/kasan/report.c:378 print_report+0x68/0x84 mm/kasan/report.c:482 kasan_report+0x8c/0xc4 mm/kasan/report.c:595 __asan_report_load4_noabort+0x20/0x2c mm/kasan/report_generic.c:380 xsk_bind+0xe38/0xeac net/xdp/xsk.c:1758 __sys_bind_socket net/socket.c:1920 [inline] __sys_bind+0x1c4/0x268 net/socket.c:1951 __do_sys_bind net/socket.c:1956 [inline] __se_sys_bind net/socket.c:1954 [inline] __arm64_sys_bind+0x84/0x9c net/socket.c:1954 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x98/0x244 arch/arm64/kernel/syscall.c:49 el0_svc_common+0xec/0x23c arch/arm64/kernel/syscall.c:121 do_el0_svc+0x4c/0x5c arch/arm64/kernel/syscall.c:140 el0_svc+0x64/0x260 arch/arm64/kernel/entry-common.c:738 el0t_64_sync_handler+0x48/0x148 arch/arm64/kernel/entry-common.c:757 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:590 Allocated by task 4718: kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x40/0x78 mm/kasan/common.c:78 kasan_save_alloc_info+0x44/0x54 mm/kasan/generic.c:570 poison_kmalloc_redzone mm/kasan/common.c:398 [inline] __kasan_kmalloc+0x9c/0xb4 mm/kasan/common.c:415 kasan_kmalloc include/linux/kasan.h:263 [inline] __kmalloc_cache_noprof+0x2e8/0x5ec mm/slub.c:5489 _kmalloc_noprof include/linux/slab.h:988 [inline] _kzalloc_noprof include/linux/slab.h:1309 [inline] nsim_queue_alloc+0x58/0x120 drivers/net/netdevsim/netdev.c:715 nsim_queue_init drivers/net/netdevsim/netdev.c:1012 [inline] nsim_init_netdevsim drivers/net/netdevsim/netdev.c:1059 [inline] nsim_create+0x7e0/0xcf4 drivers/net/netdevsim/netdev.c:1152 __nsim_dev_port_add+0x59c/0x95c drivers/net/netdevsim/dev.c:1509 nsim_dev_port_add_all+0x50/0x114 drivers/net/netdevsim/dev.c:1570 nsim_drv_probe+0x770/0xa28 drivers/net/netdevsim/dev.c:1731 nsim_bus_probe+0x20/0x30 drivers/net/netdevsim/bus.c:420 call_driver_probe drivers/base/dd.c:-1 [inline] really_probe+0x29c/0x800 drivers/base/dd.c:706 __driver_probe_device+0x1e0/0x350 drivers/base/dd.c:868 driver_probe_device+0x6c/0x19c drivers/base/dd.c:898 __device_attach_driver+0x198/0x2f8 drivers/base/dd.c:1026 bus_for_each_drv+0x144/0x1dc drivers/base/bus.c:500 __device_attach+0x248/0x390 drivers/base/dd.c:1098 device_initial_probe+0x90/0xc8 drivers/base/dd.c:1153 bus_probe_device+0x58/0x120 drivers/base/bus.c:620 device_add+0x6cc/0x9e0 drivers/base/core.c:3772 device_register+0x28/0x38 drivers/base/core.c:3854 nsim_bus_dev_new drivers/net/netdevsim/bus.c:471 [inline] new_device_store+0x2dc/0x5c0 drivers/net/netdevsim/bus.c:191 bus_attr_store+0x80/0xa4 drivers/base/bus.c:172 sysfs_kf_write+0xe0/0x108 fs/sysfs/file.c:145 kernfs_fop_write_iter+0x260/0x3b8 fs/kernfs/file.c:345 new_sync_write fs/read_write.c:595 [inline] vfs_write+0x51c/0xa0c fs/read_write.c:687 ksys_write+0x12c/0x228 fs/read_write.c:739 __do_sys_write fs/read_write.c:750 [inline] __se_sys_write fs/read_write.c:747 [inline] __arm64_sys_write+0x84/0x98 fs/read_write.c:747 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x98/0x244 arch/arm64/kernel/syscall.c:49 el0_svc_common+0xec/0x23c arch/arm64/kernel/syscall.c:121 do_el0_svc+0x4c/0x5c arch/arm64/kernel/syscall.c:140 el0_svc+0x64/0x260 arch/arm64/kernel/entry-common.c:738 el0t_64_sync_handler+0x48/0x148 arch/arm64/kernel/entry-common.c:757 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:590 Freed by task 4913: kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x40/0x78 mm/kasan/common.c:78 kasan_save_free_info+0x58/0x70 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:253 [inline] __kasan_slab_free+0x74/0xa4 mm/kasan/common.c:285 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2677 [inline] slab_free mm/slub.c:6377 [inline] kfree+0x188/0x690 mm/slub.c:6692 nsim_queue_free+0x11c/0x1a0 drivers/net/netdevsim/netdev.c:735 nsim_queue_mem_free+0xfc/0x130 drivers/net/netdevsim/netdev.c:796 netdev_rx_queue_reconfig+0x2dc/0x48c net/core/netdev_rx_queue.c:-1 netdev_rx_queue_restart+0xa4/0xec net/core/netdev_rx_queue.c:183 nsim_qreset_write+0x30c/0x48c drivers/net/netdevsim/netdev.c:887 full_proxy_write+0x11c/0x160 fs/debugfs/file.c:388 vfs_write+0x2a4/0xa0c fs/read_write.c:685 ksys_write+0x12c/0x228 fs/read_write.c:739 __do_sys_write fs/read_write.c:750 [inline] __se_sys_write fs/read_write.c:747 [inline] __arm64_sys_write+0x84/0x98 fs/read_write.c:747 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x98/0x244 arch/arm64/kernel/syscall.c:49 el0_svc_common+0xec/0x23c arch/arm64/kernel/syscall.c:121 do_el0_svc+0x4c/0x5c arch/arm64/kernel/syscall.c:140 el0_svc+0x64/0x260 arch/arm64/kernel/entry-common.c:738 el0t_64_sync_handler+0x48/0x148 arch/arm64/kernel/entry-common.c:757 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:590 The buggy address belongs to the object at ffff0000f15b2800 which belongs to the cache kmalloc-cg-1k of size 1024 The buggy address is located 396 bytes inside of freed 1024-byte region [ffff0000f15b2800, ffff0000f15b2c00) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1315b0 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0x5ffc00000000040(head|node=0|zone=2|lastcpupid=0x7ff) page_type: f5(slab) raw: 05ffc00000000040 ffff0000c000b280 dead000000000100 dead000000000122 raw: 0000000000000000 0000000800100010 00000000f5000000 0000000000000000 head: 05ffc00000000040 ffff0000c000b280 dead000000000100 dead000000000122 head: 0000000000000000 0000000800100010 00000000f5000000 0000000000000000 head: 05ffc00000000003 fffffdffc3c56c01 00000000ffffffff 00000000ffffffff head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000008 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff0000f15b2880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff0000f15b2900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff0000f15b2980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff0000f15b2a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff0000f15b2a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== Illegal XDP return value 4294965632 on prog (id 3) dev syz_tun, expect packet loss!