================================================================== BUG: KASAN: use-after-free in unix_stream_read_actor+0xa3/0xb0 net/unix/af_unix.c:2920 Read of size 4 at addr ffff88810fffb044 by task syz-executor.0/1353 CPU: 1 PID: 1353 Comm: syz-executor.0 Not tainted 6.1.43-syzkaller-1150379-gd2c0f4c4502a #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/09/2023 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x151/0x1b7 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:316 [inline] print_report+0x158/0x4e0 mm/kasan/report.c:427 kasan_report+0x13c/0x170 mm/kasan/report.c:531 __asan_report_load4_noabort+0x14/0x20 mm/kasan/report_generic.c:350 unix_stream_read_actor+0xa3/0xb0 net/unix/af_unix.c:2920 unix_stream_recv_urg+0x1b4/0x300 net/unix/af_unix.c:2647 unix_stream_read_generic+0x2140/0x2220 net/unix/af_unix.c:2726 unix_stream_recvmsg+0x222/0x2b0 net/unix/af_unix.c:2957 ____sys_recvmsg+0x285/0x530 ___sys_recvmsg net/socket.c:2743 [inline] __sys_recvmsg+0x2e9/0x3d0 net/socket.c:2773 __do_sys_recvmsg net/socket.c:2783 [inline] __se_sys_recvmsg net/socket.c:2780 [inline] __x64_sys_recvmsg+0x7f/0x90 net/socket.c:2780 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+0x63/0xcd RIP: 0033:0x7f149bc7cae9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f149c9050c8 EFLAGS: 00000246 ORIG_RAX: 000000000000002f RAX: ffffffffffffffda RBX: 00007f149bd9c120 RCX: 00007f149bc7cae9 RDX: 0000000040010083 RSI: 0000000020000140 RDI: 0000000000000004 RBP: 00007f149bcc847a R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000006e R14: 00007f149bd9c120 R15: 00007ffec5e760a8 Allocated by task 1352: kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:52 kasan_save_alloc_info+0x1f/0x30 mm/kasan/generic.c:505 __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:333 kasan_slab_alloc include/linux/kasan.h:202 [inline] slab_post_alloc_hook+0x53/0x2c0 mm/slab.h:768 slab_alloc_node mm/slub.c:3421 [inline] kmem_cache_alloc_node+0x18a/0x2d0 mm/slub.c:3466 __alloc_skb+0xcc/0x2e0 net/core/skbuff.c:497 alloc_skb include/linux/skbuff.h:1275 [inline] alloc_skb_with_frags+0xa6/0x680 net/core/skbuff.c:6148 sock_alloc_send_pskb+0x915/0xa50 net/core/sock.c:2732 sock_alloc_send_skb include/net/sock.h:1908 [inline] queue_oob+0x102/0x8e0 net/unix/af_unix.c:2114 unix_stream_sendmsg+0xe10/0x1070 net/unix/af_unix.c:2251 sock_sendmsg_nosec net/socket.c:716 [inline] sock_sendmsg net/socket.c:736 [inline] ____sys_sendmsg+0x5dc/0x9d0 net/socket.c:2482 ___sys_sendmsg net/socket.c:2536 [inline] __sys_sendmsg+0x2a9/0x390 net/socket.c:2565 __do_sys_sendmsg net/socket.c:2574 [inline] __se_sys_sendmsg net/socket.c:2572 [inline] __x64_sys_sendmsg+0x7f/0x90 net/socket.c:2572 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+0x63/0xcd Freed by task 1352: kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:52 kasan_save_free_info+0x2b/0x40 mm/kasan/generic.c:516 ____kasan_slab_free+0x131/0x180 mm/kasan/common.c:241 __kasan_slab_free+0x11/0x20 mm/kasan/common.c:249 kasan_slab_free include/linux/kasan.h:178 [inline] slab_free_hook mm/slub.c:1745 [inline] slab_free_freelist_hook mm/slub.c:1771 [inline] slab_free mm/slub.c:3684 [inline] kmem_cache_free+0x291/0x510 mm/slub.c:3706 kfree_skbmem+0x104/0x170 __kfree_skb net/core/skbuff.c:869 [inline] consume_skb+0xb4/0x250 net/core/skbuff.c:1033 queue_oob+0x52c/0x8e0 net/unix/af_unix.c:2145 unix_stream_sendmsg+0xe10/0x1070 net/unix/af_unix.c:2251 sock_sendmsg_nosec net/socket.c:716 [inline] sock_sendmsg net/socket.c:736 [inline] ____sys_sendmsg+0x5dc/0x9d0 net/socket.c:2482 ___sys_sendmsg net/socket.c:2536 [inline] __sys_sendmsg+0x2a9/0x390 net/socket.c:2565 __do_sys_sendmsg net/socket.c:2574 [inline] __se_sys_sendmsg net/socket.c:2572 [inline] __x64_sys_sendmsg+0x7f/0x90 net/socket.c:2572 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+0x63/0xcd The buggy address belongs to the object at ffff88810fffb000 which belongs to the cache skbuff_head_cache of size 256 The buggy address is located 68 bytes inside of 256-byte region [ffff88810fffb000, ffff88810fffb100) The buggy address belongs to the physical page: page:ffffea00043ffec0 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x10fffb flags: 0x4000000000000200(slab|zone=1) raw: 4000000000000200 ffffea0004443700 dead000000000006 ffff888100233080 raw: 0000000000000000 00000000000c000c 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 0, migratetype Unmovable, gfp_mask 0x12cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY), pid 103, tgid 103 (udevadm), ts 4176884751, free_ts 4176816638 set_page_owner include/linux/page_owner.h:33 [inline] post_alloc_hook+0x213/0x220 mm/page_alloc.c:2586 prep_new_page+0x1b/0x110 mm/page_alloc.c:2593 get_page_from_freelist+0x2878/0x2910 mm/page_alloc.c:4410 __alloc_pages+0x3a1/0x780 mm/page_alloc.c:5698 alloc_slab_page+0x6c/0xf0 allocate_slab mm/slub.c:1962 [inline] new_slab+0x90/0x3e0 mm/slub.c:2015 ___slab_alloc+0x6f9/0xb80 mm/slub.c:3203 __slab_alloc+0x5d/0xa0 mm/slub.c:3302 slab_alloc_node mm/slub.c:3387 [inline] slab_alloc mm/slub.c:3429 [inline] __kmem_cache_alloc_lru mm/slub.c:3436 [inline] kmem_cache_alloc+0x1b9/0x2c0 mm/slub.c:3445 skb_clone+0x1f8/0x380 net/core/skbuff.c:1658 do_one_broadcast net/netlink/af_netlink.c:1459 [inline] netlink_broadcast+0x62d/0x1140 net/netlink/af_netlink.c:1525 uevent_net_broadcast_untagged lib/kobject_uevent.c:331 [inline] kobject_uevent_net_broadcast+0x3a1/0x590 lib/kobject_uevent.c:409 kobject_uevent_env+0x53c/0x720 lib/kobject_uevent.c:593 kobject_synth_uevent+0x4eb/0xae0 lib/kobject_uevent.c:208 uevent_store+0x4b/0x70 drivers/base/bus.c:581 drv_attr_store+0x78/0xa0 drivers/base/bus.c:77 page last free stack trace: reset_page_owner include/linux/page_owner.h:26 [inline] free_pages_prepare mm/page_alloc.c:1494 [inline] free_pcp_prepare mm/page_alloc.c:1568 [inline] free_unref_page_prepare+0x83d/0x850 mm/page_alloc.c:3500 free_unref_page+0xbc/0x650 mm/page_alloc.c:3597 free_the_page mm/page_alloc.c:794 [inline] __free_pages+0x61/0xf0 mm/page_alloc.c:5787 free_pages+0x7c/0x90 mm/page_alloc.c:5798 selinux_genfs_get_sid+0x24d/0x2a0 security/selinux/hooks.c:1303 inode_doinit_with_dentry+0x8d2/0x1070 security/selinux/hooks.c:1498 selinux_d_instantiate+0x27/0x40 security/selinux/hooks.c:6329 security_d_instantiate+0x9f/0x100 security/security.c:2064 d_splice_alias+0x6d/0x390 fs/dcache.c:3146 kernfs_iop_lookup+0x29e/0x2f0 fs/kernfs/dir.c:1181 lookup_open fs/namei.c:3391 [inline] open_last_lookups fs/namei.c:3481 [inline] path_openat+0x10fd/0x2d60 fs/namei.c:3711 do_filp_open+0x230/0x480 fs/namei.c:3741 do_sys_openat2+0x13f/0x850 fs/open.c:1341 do_sys_open fs/open.c:1357 [inline] __do_sys_openat fs/open.c:1373 [inline] __se_sys_openat fs/open.c:1368 [inline] __x64_sys_openat+0x243/0x290 fs/open.c:1368 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+0x63/0xcd Memory state around the buggy address: ffff88810fffaf00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88810fffaf80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff88810fffb000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88810fffb080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88810fffb100: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb ==================================================================