================================================================== BUG: KASAN: use-after-free in genlmsg_multicast_netns include/net/genetlink.h:314 [inline] BUG: KASAN: use-after-free in devlink_notify+0xeb/0x150 net/core/devlink.c:756 Read of size 8 at addr ffff88807e935098 by task syz-executor.3/17208 CPU: 1 PID: 17208 Comm: syz-executor.3 Not tainted 5.15.151-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/29/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106 print_address_description+0x63/0x3b0 mm/kasan/report.c:248 __kasan_report mm/kasan/report.c:434 [inline] kasan_report+0x16b/0x1c0 mm/kasan/report.c:451 genlmsg_multicast_netns include/net/genetlink.h:314 [inline] devlink_notify+0xeb/0x150 net/core/devlink.c:756 devlink_unregister+0x13e/0x1d0 net/core/devlink.c:8987 nsim_dev_remove+0xdf/0x100 drivers/net/netdevsim/dev.c:1583 __device_release_driver drivers/base/dd.c:1227 [inline] device_release_driver_internal+0x4cb/0x7f0 drivers/base/dd.c:1262 bus_remove_device+0x2e5/0x400 drivers/base/bus.c:529 device_del+0x6e2/0xbd0 drivers/base/core.c:3582 device_unregister+0x1c/0xc0 drivers/base/core.c:3615 nsim_bus_dev_del drivers/net/netdevsim/bus.c:454 [inline] del_device_store+0x321/0x470 drivers/net/netdevsim/bus.c:354 kernfs_fop_write_iter+0x3a2/0x4f0 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+0xacf/0xe50 fs/read_write.c:594 ksys_write+0x1a2/0x2c0 fs/read_write.c:647 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x61/0xcb RIP: 0033:0x7fb49ab77aef 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:00007ffdd6f10840 EFLAGS: 00000293 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 00007fb49ab77aef RDX: 0000000000000001 RSI: 00007ffdd6f10890 RDI: 0000000000000005 RBP: 00007fb49abc5021 R08: 0000000000000000 R09: 00007ffdd6f10697 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000001 R13: 00007ffdd6f10890 R14: 00007fb49b7cf620 R15: 0000000000000003 Allocated by task 13629: 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+0x8e/0xc0 mm/kasan/common.c:467 kasan_slab_alloc include/linux/kasan.h:254 [inline] slab_post_alloc_hook+0x53/0x380 mm/slab.h:519 slab_alloc_node mm/slub.c:3220 [inline] slab_alloc mm/slub.c:3228 [inline] kmem_cache_alloc+0xf3/0x280 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+0x143/0x5d0 net/core/net_namespace.c:460 create_new_namespaces+0x425/0x7a0 kernel/nsproxy.c:110 unshare_nsproxy_namespaces+0x11e/0x170 kernel/nsproxy.c:226 ksys_unshare+0x580/0xb20 kernel/fork.c:3101 __do_sys_unshare kernel/fork.c:3175 [inline] __se_sys_unshare kernel/fork.c:3173 [inline] __x64_sys_unshare+0x34/0x40 kernel/fork.c:3173 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x61/0xcb Freed by task 7327: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track+0x4b/0x80 mm/kasan/common.c:46 kasan_set_free_info+0x1f/0x40 mm/kasan/generic.c:360 ____kasan_slab_free+0xd8/0x120 mm/kasan/common.c:366 kasan_slab_free include/linux/kasan.h:230 [inline] slab_free_hook mm/slub.c:1705 [inline] slab_free_freelist_hook+0xdd/0x160 mm/slub.c:1731 slab_free mm/slub.c:3499 [inline] kmem_cache_free+0x91/0x1f0 mm/slub.c:3515 net_free net/core/net_namespace.c:434 [inline] cleanup_net+0xab5/0xb60 net/core/net_namespace.c:617 process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2310 worker_thread+0xaca/0x1280 kernel/workqueue.c:2457 kthread+0x3f6/0x4f0 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298 The buggy address belongs to the object at ffff88807e934ec0 which belongs to the cache net_namespace of size 6464 The buggy address is located 472 bytes inside of 6464-byte region [ffff88807e934ec0, ffff88807e936800) The buggy address belongs to the page: page:ffffea0001fa4c00 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88807e930000 pfn:0x7e930 head:ffffea0001fa4c00 order:3 compound_mapcount:0 compound_pincount:0 memcg:ffff88801f846d01 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 0000000000000000 0000000100000001 ffff888011dea3c0 raw: ffff88807e930000 0000000080040003 00000001ffffffff ffff88801f846d01 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Unmovable, gfp_mask 0x1d20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 4404, ts 151269764636, free_ts 128782975239 prep_new_page mm/page_alloc.c:2426 [inline] get_page_from_freelist+0x322a/0x33c0 mm/page_alloc.c:4159 __alloc_pages+0x272/0x700 mm/page_alloc.c:5421 alloc_slab_page mm/slub.c:1775 [inline] allocate_slab mm/slub.c:1912 [inline] new_slab+0xbb/0x4b0 mm/slub.c:1975 ___slab_alloc+0x6f6/0xe10 mm/slub.c:3008 __slab_alloc mm/slub.c:3095 [inline] slab_alloc_node mm/slub.c:3186 [inline] slab_alloc mm/slub.c:3228 [inline] kmem_cache_alloc+0x18e/0x280 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+0x143/0x5d0 net/core/net_namespace.c:460 create_new_namespaces+0x425/0x7a0 kernel/nsproxy.c:110 copy_namespaces+0x365/0x3b0 kernel/nsproxy.c:178 copy_process+0x1841/0x3ef0 kernel/fork.c:2209 kernel_clone+0x210/0x960 kernel/fork.c:2604 __do_sys_clone kernel/fork.c:2721 [inline] __se_sys_clone kernel/fork.c:2705 [inline] __x64_sys_clone+0x23f/0x290 kernel/fork.c:2705 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x61/0xcb page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1340 [inline] free_pcp_prepare mm/page_alloc.c:1391 [inline] free_unref_page_prepare+0xc34/0xcf0 mm/page_alloc.c:3317 free_unref_page+0x95/0x2d0 mm/page_alloc.c:3396 free_slab mm/slub.c:2015 [inline] discard_slab mm/slub.c:2021 [inline] __unfreeze_partials+0x1b7/0x210 mm/slub.c:2507 put_cpu_partial+0x132/0x1a0 mm/slub.c:2587 do_slab_free mm/slub.c:3487 [inline] ___cache_free+0xe3/0x100 mm/slub.c:3506 qlist_free_all+0x36/0x90 mm/kasan/quarantine.c:176 kasan_quarantine_reduce+0x162/0x180 mm/kasan/quarantine.c:283 __kasan_slab_alloc+0x2f/0xc0 mm/kasan/common.c:444 kasan_slab_alloc include/linux/kasan.h:254 [inline] slab_post_alloc_hook+0x53/0x380 mm/slab.h:519 slab_alloc_node mm/slub.c:3220 [inline] slab_alloc mm/slub.c:3228 [inline] kmem_cache_alloc+0xf3/0x280 mm/slub.c:3233 getname_flags+0xb8/0x4e0 fs/namei.c:138 user_path_at_empty+0x2a/0x180 fs/namei.c:2882 do_readlinkat+0x114/0x3a0 fs/stat.c:442 __do_sys_readlink fs/stat.c:475 [inline] __se_sys_readlink fs/stat.c:472 [inline] __x64_sys_readlink+0x7b/0x90 fs/stat.c:472 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x61/0xcb Memory state around the buggy address: ffff88807e934f80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88807e935000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88807e935080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88807e935100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88807e935180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================