================================================================== BUG: KASAN: use-after-free in genlmsg_multicast_netns include/net/genetlink.h:314 [inline] BUG: KASAN: use-after-free in devlink_notify+0xe4/0x14c net/core/devlink.c:756 Read of size 8 at addr ffff0000cab001d8 by task syz-executor.1/4814 CPU: 0 PID: 4814 Comm: syz-executor.1 Not tainted 5.15.151-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024 Call trace: dump_backtrace+0x0/0x530 arch/arm64/kernel/stacktrace.c:152 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:216 __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x108/0x170 lib/dump_stack.c:106 print_address_description+0x7c/0x3f0 mm/kasan/report.c:248 __kasan_report mm/kasan/report.c:434 [inline] kasan_report+0x174/0x1e4 mm/kasan/report.c:451 __asan_report_load8_noabort+0x44/0x50 mm/kasan/report_generic.c:309 genlmsg_multicast_netns include/net/genetlink.h:314 [inline] devlink_notify+0xe4/0x14c net/core/devlink.c:756 devlink_unregister+0x144/0x208 net/core/devlink.c:8987 nsim_dev_remove+0xd8/0x108 drivers/net/netdevsim/dev.c:1583 nsim_bus_remove+0x20/0x30 drivers/net/netdevsim/bus.c:381 __device_release_driver drivers/base/dd.c:1227 [inline] device_release_driver_internal+0x428/0x6ac drivers/base/dd.c:1262 device_release_driver+0x28/0x38 drivers/base/dd.c:1285 bus_remove_device+0x298/0x38c drivers/base/bus.c:529 device_del+0x57c/0x9b4 drivers/base/core.c:3582 device_unregister+0x2c/0xcc drivers/base/core.c:3615 nsim_bus_dev_del drivers/net/netdevsim/bus.c:454 [inline] del_device_store+0x2a4/0x3bc drivers/net/netdevsim/bus.c:354 bus_attr_store+0x80/0xa4 drivers/base/bus.c:122 sysfs_kf_write+0x200/0x280 fs/sysfs/file.c:139 kernfs_fop_write_iter+0x334/0x48c fs/kernfs/file.c:296 call_write_iter include/linux/fs.h:2148 [inline] new_sync_write fs/read_write.c:507 [inline] vfs_write+0x87c/0xb3c fs/read_write.c:594 ksys_write+0x15c/0x26c fs/read_write.c:647 __do_sys_write fs/read_write.c:659 [inline] __se_sys_write fs/read_write.c:656 [inline] __arm64_sys_write+0x7c/0x90 fs/read_write.c:656 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:52 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142 do_el0_svc+0x58/0x14c arch/arm64/kernel/syscall.c:181 el0_svc+0x7c/0x1f0 arch/arm64/kernel/entry-common.c:608 el0t_64_sync_handler+0x84/0xe4 arch/arm64/kernel/entry-common.c:626 el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584 Allocated by task 3988: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track mm/kasan/common.c:46 [inline] set_alloc_info mm/kasan/common.c:434 [inline] __kasan_slab_alloc+0x8c/0xcc mm/kasan/common.c:467 kasan_slab_alloc include/linux/kasan.h:254 [inline] slab_post_alloc_hook+0x74/0x3f4 mm/slab.h:519 slab_alloc_node mm/slub.c:3220 [inline] slab_alloc mm/slub.c:3228 [inline] kmem_cache_alloc+0x1dc/0x45c mm/slub.c:3233 kmem_cache_zalloc include/linux/slab.h:711 [inline] net_alloc net/core/net_namespace.c:405 [inline] copy_net_ns+0x128/0x5e4 net/core/net_namespace.c:460 create_new_namespaces+0x330/0x61c kernel/nsproxy.c:110 unshare_nsproxy_namespaces+0x108/0x158 kernel/nsproxy.c:226 ksys_unshare+0x45c/0x874 kernel/fork.c:3101 __do_sys_unshare kernel/fork.c:3175 [inline] __se_sys_unshare kernel/fork.c:3173 [inline] __arm64_sys_unshare+0x3c/0x50 kernel/fork.c:3173 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:52 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142 do_el0_svc+0x58/0x14c arch/arm64/kernel/syscall.c:181 el0_svc+0x7c/0x1f0 arch/arm64/kernel/entry-common.c:608 el0t_64_sync_handler+0x84/0xe4 arch/arm64/kernel/entry-common.c:626 el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584 Freed by task 4710: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track+0x4c/0x84 mm/kasan/common.c:46 kasan_set_free_info+0x28/0x4c mm/kasan/generic.c:360 ____kasan_slab_free+0x118/0x164 mm/kasan/common.c:366 __kasan_slab_free+0x18/0x28 mm/kasan/common.c:374 kasan_slab_free include/linux/kasan.h:230 [inline] slab_free_hook mm/slub.c:1705 [inline] slab_free_freelist_hook+0x128/0x1ec mm/slub.c:1731 slab_free mm/slub.c:3499 [inline] kmem_cache_free+0xdc/0x3c4 mm/slub.c:3515 net_free net/core/net_namespace.c:434 [inline] cleanup_net+0x8a0/0x9bc net/core/net_namespace.c:617 process_one_work+0x790/0x11b8 kernel/workqueue.c:2310 worker_thread+0x910/0x1034 kernel/workqueue.c:2457 kthread+0x37c/0x45c kernel/kthread.c:319 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:870 The buggy address belongs to the object at ffff0000cab00000 which belongs to the cache net_namespace of size 6464 The buggy address is located 472 bytes inside of 6464-byte region [ffff0000cab00000, ffff0000cab01940) The buggy address belongs to the page: page:000000004d938444 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x10ab00 head:000000004d938444 order:3 compound_mapcount:0 compound_pincount:0 flags: 0x5ffc00000010200(slab|head|node=0|zone=2|lastcpupid=0x7ff) raw: 05ffc00000010200 0000000000000000 dead000000000122 ffff0000c0840000 raw: 0000000000000000 0000000080040004 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff0000cab00080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff0000cab00100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff0000cab00180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff0000cab00200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff0000cab00280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== Unable to handle kernel paging request at virtual address dfff800000000006 Mem abort info: ESR = 0x0000000096000006 EC = 0x25: DABT (current EL), IL = 32 bits SET = 0, FnV = 0 EA = 0, S1PTW = 0 FSC = 0x06: level 2 translation fault Data abort info: ISV = 0, ISS = 0x00000006 CM = 0, WnR = 0 [dfff800000000006] address between user and kernel address ranges Internal error: Oops: 0000000096000006 [#1] PREEMPT SMP Modules linked in: CPU: 0 PID: 4814 Comm: syz-executor.1 Tainted: G B 5.15.151-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024 pstate: 80400005 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : read_pnet include/net/net_namespace.h:327 [inline] pc : sock_net include/net/sock.h:2722 [inline] pc : netlink_broadcast_filtered+0x54/0xdf0 net/netlink/af_netlink.c:1513 lr : netlink_broadcast_filtered+0x4c/0xdf0 net/netlink/af_netlink.c:1512 sp : ffff800018ec74d0 x29: ffff800018ec7560 x28: 0000000000000000 x27: 0000000000000000 x26: dfff800000000000 x25: 0000000000000000 x24: 0000000000000000 x23: 0000000000000cc0 x22: 0000000000000004 x21: 0000000000000000 x20: 0000000000000030 x19: ffff0000ccf21640 x18: 1fffe000368fe78e x17: 1fffe000368fe78e x16: ffff800011977874 x15: ffff8000149aeb80 x14: ffff0001b47f3c80 x13: ffff0001b47f3c7c x12: ffff700002de2564 x11: 0000000000000000 x10: 0000000000000000 x9 : ffff0000d30f51c0 x8 : 0000000000000006 x7 : 0000000000000000 x6 : 0000000000000000 x5 : 0000000000000000 x4 : 0000000000000cc0 x3 : 0000000000000004 x2 : 0000000000000000 x1 : ffff0000ccf21640 x0 : 0000000000000000 Call trace: read_pnet include/net/net_namespace.h:327 [inline] sock_net include/net/sock.h:2722 [inline] netlink_broadcast_filtered+0x54/0xdf0 net/netlink/af_netlink.c:1513 netlink_broadcast+0x50/0x68 net/netlink/af_netlink.c:1562 nlmsg_multicast include/net/netlink.h:1033 [inline] genlmsg_multicast_netns include/net/genetlink.h:314 [inline] devlink_notify+0x114/0x14c net/core/devlink.c:756 devlink_unregister+0x144/0x208 net/core/devlink.c:8987 nsim_dev_remove+0xd8/0x108 drivers/net/netdevsim/dev.c:1583 nsim_bus_remove+0x20/0x30 drivers/net/netdevsim/bus.c:381 __device_release_driver drivers/base/dd.c:1227 [inline] device_release_driver_internal+0x428/0x6ac drivers/base/dd.c:1262 device_release_driver+0x28/0x38 drivers/base/dd.c:1285 bus_remove_device+0x298/0x38c drivers/base/bus.c:529 device_del+0x57c/0x9b4 drivers/base/core.c:3582 device_unregister+0x2c/0xcc drivers/base/core.c:3615 nsim_bus_dev_del drivers/net/netdevsim/bus.c:454 [inline] del_device_store+0x2a4/0x3bc drivers/net/netdevsim/bus.c:354 bus_attr_store+0x80/0xa4 drivers/base/bus.c:122 sysfs_kf_write+0x200/0x280 fs/sysfs/file.c:139 kernfs_fop_write_iter+0x334/0x48c fs/kernfs/file.c:296 call_write_iter include/linux/fs.h:2148 [inline] new_sync_write fs/read_write.c:507 [inline] vfs_write+0x87c/0xb3c fs/read_write.c:594 ksys_write+0x15c/0x26c fs/read_write.c:647 __do_sys_write fs/read_write.c:659 [inline] __se_sys_write fs/read_write.c:656 [inline] __arm64_sys_write+0x7c/0x90 fs/read_write.c:656 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:52 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142 do_el0_svc+0x58/0x14c arch/arm64/kernel/syscall.c:181 el0_svc+0x7c/0x1f0 arch/arm64/kernel/entry-common.c:608 el0t_64_sync_handler+0x84/0xe4 arch/arm64/kernel/entry-common.c:626 el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584 Code: f2fbfffa 960ea52d 9100c334 d343fe88 (387a6908) ---[ end trace 8d28afd9e9a6a7cc ]--- ---------------- Code disassembly (best guess): 0: f2fbfffa movk x26, #0xdfff, lsl #48 4: 960ea52d bl 0xfffffffff83a94b8 8: 9100c334 add x20, x25, #0x30 c: d343fe88 lsr x8, x20, #3 * 10: 387a6908 ldrb w8, [x8, x26] <-- trapping instruction