================================================================== BUG: KASAN: use-after-free in macvlan_dev_get_iflink+0x5f/0x70 drivers/net/macvlan.c:1138 Read of size 4 at addr ffff8880729a80d8 by task syz-executor.1/24519 CPU: 0 PID: 24519 Comm: syz-executor.1 Not tainted 5.17.0-rc4-syzkaller #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.14.0-2 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 print_address_description.constprop.0.cold+0x8d/0x336 mm/kasan/report.c:255 __kasan_report mm/kasan/report.c:442 [inline] kasan_report.cold+0x83/0xdf mm/kasan/report.c:459 macvlan_dev_get_iflink+0x5f/0x70 drivers/net/macvlan.c:1138 dev_get_iflink+0x73/0xe0 net/core/dev.c:618 default_operstate net/core/link_watch.c:41 [inline] rfc2863_policy+0x233/0x2d0 net/core/link_watch.c:53 linkwatch_do_dev+0x2a/0x150 net/core/link_watch.c:160 linkwatch_forget_dev+0x17d/0x210 net/core/link_watch.c:249 netdev_wait_allrefs net/core/dev.c:9832 [inline] netdev_run_todo+0x40b/0xaa0 net/core/dev.c:9950 rtnl_unlock net/core/rtnetlink.c:112 [inline] rtnetlink_rcv_msg+0x420/0xb80 net/core/rtnetlink.c:5595 netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c:2494 netlink_unicast_kernel net/netlink/af_netlink.c:1317 [inline] netlink_unicast+0x539/0x7e0 net/netlink/af_netlink.c:1343 netlink_sendmsg+0x904/0xe00 net/netlink/af_netlink.c:1919 sock_sendmsg_nosec net/socket.c:705 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:725 ____sys_sendmsg+0x6e8/0x810 net/socket.c:2413 ___sys_sendmsg+0xf3/0x170 net/socket.c:2467 __sys_sendmsg+0xe5/0x1b0 net/socket.c:2496 do_syscall_32_irqs_on arch/x86/entry/common.c:112 [inline] __do_fast_syscall_32+0x65/0xf0 arch/x86/entry/common.c:178 do_fast_syscall_32+0x2f/0x70 arch/x86/entry/common.c:203 entry_SYSENTER_compat_after_hwframe+0x4d/0x5c RIP: 0023:0xf6f1f549 Code: 03 74 c0 01 10 05 03 74 b8 01 10 06 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 8d b4 26 00 00 00 00 8d b4 26 00 00 00 00 RSP: 002b:00000000f58f85cc EFLAGS: 00000296 ORIG_RAX: 0000000000000172 RAX: ffffffffffffffda RBX: 0000000000000006 RCX: 0000000020000340 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 Allocated by task 24510: kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38 kasan_set_track mm/kasan/common.c:45 [inline] set_alloc_info mm/kasan/common.c:436 [inline] ____kasan_kmalloc mm/kasan/common.c:515 [inline] ____kasan_kmalloc mm/kasan/common.c:474 [inline] __kasan_kmalloc+0xa9/0xd0 mm/kasan/common.c:524 kmalloc_node include/linux/slab.h:604 [inline] kvmalloc_node+0x3e/0x100 mm/util.c:580 kvmalloc include/linux/slab.h:732 [inline] kvzalloc include/linux/slab.h:740 [inline] alloc_netdev_mqs+0x98/0x1070 net/core/dev.c:10163 rtnl_create_link+0x9d7/0xc00 net/core/rtnetlink.c:3202 __rtnl_newlink+0xf82/0x1760 net/core/rtnetlink.c:3471 rtnl_newlink+0x64/0xa0 net/core/rtnetlink.c:3529 rtnetlink_rcv_msg+0x413/0xb80 net/core/rtnetlink.c:5594 netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c:2494 netlink_unicast_kernel net/netlink/af_netlink.c:1317 [inline] netlink_unicast+0x539/0x7e0 net/netlink/af_netlink.c:1343 netlink_sendmsg+0x904/0xe00 net/netlink/af_netlink.c:1919 sock_sendmsg_nosec net/socket.c:705 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:725 ____sys_sendmsg+0x6e8/0x810 net/socket.c:2413 ___sys_sendmsg+0xf3/0x170 net/socket.c:2467 __sys_sendmsg+0xe5/0x1b0 net/socket.c:2496 do_syscall_32_irqs_on arch/x86/entry/common.c:112 [inline] __do_fast_syscall_32+0x65/0xf0 arch/x86/entry/common.c:178 do_fast_syscall_32+0x2f/0x70 arch/x86/entry/common.c:203 entry_SYSENTER_compat_after_hwframe+0x4d/0x5c Freed by task 24510: kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38 kasan_set_track+0x21/0x30 mm/kasan/common.c:45 kasan_set_free_info+0x20/0x30 mm/kasan/generic.c:370 ____kasan_slab_free mm/kasan/common.c:366 [inline] ____kasan_slab_free+0x126/0x160 mm/kasan/common.c:328 kasan_slab_free include/linux/kasan.h:236 [inline] slab_free_hook mm/slub.c:1728 [inline] slab_free_freelist_hook+0x8b/0x1c0 mm/slub.c:1754 slab_free mm/slub.c:3509 [inline] kfree+0xd0/0x390 mm/slub.c:4562 kvfree+0x42/0x50 mm/util.c:613 device_release+0x9f/0x240 drivers/base/core.c:2229 kobject_cleanup lib/kobject.c:705 [inline] kobject_release lib/kobject.c:736 [inline] kref_put include/linux/kref.h:65 [inline] kobject_put+0x1c8/0x540 lib/kobject.c:753 netdev_run_todo+0x778/0xaa0 net/core/dev.c:9973 rtnl_unlock net/core/rtnetlink.c:112 [inline] rtnetlink_rcv_msg+0x420/0xb80 net/core/rtnetlink.c:5595 netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c:2494 netlink_unicast_kernel net/netlink/af_netlink.c:1317 [inline] netlink_unicast+0x539/0x7e0 net/netlink/af_netlink.c:1343 netlink_sendmsg+0x904/0xe00 net/netlink/af_netlink.c:1919 sock_sendmsg_nosec net/socket.c:705 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:725 ____sys_sendmsg+0x6e8/0x810 net/socket.c:2413 ___sys_sendmsg+0xf3/0x170 net/socket.c:2467 __sys_sendmsg+0xe5/0x1b0 net/socket.c:2496 do_syscall_32_irqs_on arch/x86/entry/common.c:112 [inline] __do_fast_syscall_32+0x65/0xf0 arch/x86/entry/common.c:178 do_fast_syscall_32+0x2f/0x70 arch/x86/entry/common.c:203 entry_SYSENTER_compat_after_hwframe+0x4d/0x5c The buggy address belongs to the object at ffff8880729a8000 which belongs to the cache kmalloc-cg-4k of size 4096 The buggy address is located 216 bytes inside of 4096-byte region [ffff8880729a8000, ffff8880729a9000) The buggy address belongs to the page: page:ffffea0001ca6a00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x729a8 head:ffffea0001ca6a00 order:3 compound_mapcount:0 compound_pincount:0 memcg:ffff8880587565c1 flags: 0x4fff00000010200(slab|head|node=1|zone=1|lastcpupid=0x7ff) raw: 04fff00000010200 0000000000000000 dead000000000122 ffff888010c4c140 raw: 0000000000000000 0000000000040004 00000001ffffffff ffff8880587565c1 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Unmovable, gfp_mask 0x1d60c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_RETRY_MAYFAIL|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 24278, ts 2502146470377, free_ts 2479406926795 prep_new_page mm/page_alloc.c:2434 [inline] get_page_from_freelist+0xa72/0x2f50 mm/page_alloc.c:4165 __alloc_pages+0x1b2/0x500 mm/page_alloc.c:5389 alloc_pages+0x1aa/0x310 mm/mempolicy.c:2271 alloc_slab_page mm/slub.c:1799 [inline] allocate_slab+0x27f/0x3c0 mm/slub.c:1944 new_slab mm/slub.c:2004 [inline] ___slab_alloc+0xbe1/0x12b0 mm/slub.c:3018 __slab_alloc.constprop.0+0x4d/0xa0 mm/slub.c:3105 slab_alloc_node mm/slub.c:3196 [inline] __kmalloc_node+0x339/0x4a0 mm/slub.c:4468 kmalloc_node include/linux/slab.h:604 [inline] kvmalloc_node+0x3e/0x100 mm/util.c:580 kvmalloc include/linux/slab.h:732 [inline] kvzalloc include/linux/slab.h:740 [inline] alloc_netdev_mqs+0x98/0x1070 net/core/dev.c:10163 ip6gre_init_net+0x1b6/0x630 net/ipv6/ip6_gre.c:1593 ops_init+0xaf/0x470 net/core/net_namespace.c:140 setup_net+0x554/0xbb0 net/core/net_namespace.c:330 copy_net_ns+0x318/0x760 net/core/net_namespace.c:474 create_new_namespaces+0x3f6/0xb20 kernel/nsproxy.c:110 unshare_nsproxy_namespaces+0xc1/0x1f0 kernel/nsproxy.c:226 ksys_unshare+0x445/0x920 kernel/fork.c:3048 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1352 [inline] free_pcp_prepare+0x374/0x870 mm/page_alloc.c:1404 free_unref_page_prepare mm/page_alloc.c:3325 [inline] free_unref_page+0x19/0x690 mm/page_alloc.c:3404 __unfreeze_partials+0x320/0x340 mm/slub.c:2536 qlink_free mm/kasan/quarantine.c:157 [inline] qlist_free_all+0x6d/0x160 mm/kasan/quarantine.c:176 kasan_quarantine_reduce+0x180/0x200 mm/kasan/quarantine.c:283 __kasan_slab_alloc+0xa2/0xc0 mm/kasan/common.c:446 kasan_slab_alloc include/linux/kasan.h:260 [inline] slab_post_alloc_hook mm/slab.h:732 [inline] slab_alloc_node mm/slub.c:3230 [inline] kmem_cache_alloc_node+0x2c3/0x4f0 mm/slub.c:3266 __alloc_skb+0x215/0x340 net/core/skbuff.c:414 alloc_skb include/linux/skbuff.h:1158 [inline] nlmsg_new include/net/netlink.h:953 [inline] inet6_netconf_notify_devconf+0xa0/0x1e0 net/ipv6/addrconf.c:584 __addrconf_sysctl_unregister net/ipv6/addrconf.c:7077 [inline] addrconf_exit_net+0xe5/0x2a0 net/ipv6/addrconf.c:7181 ops_exit_list+0xb0/0x170 net/core/net_namespace.c:168 setup_net+0x77e/0xbb0 net/core/net_namespace.c:353 copy_net_ns+0x318/0x760 net/core/net_namespace.c:474 create_new_namespaces+0x3f6/0xb20 kernel/nsproxy.c:110 unshare_nsproxy_namespaces+0xc1/0x1f0 kernel/nsproxy.c:226 ksys_unshare+0x445/0x920 kernel/fork.c:3048 Memory state around the buggy address: ffff8880729a7f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8880729a8000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8880729a8080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880729a8100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880729a8180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== ---------------- Code disassembly (best guess): 0: 03 74 c0 01 add 0x1(%rax,%rax,8),%esi 4: 10 05 03 74 b8 01 adc %al,0x1b87403(%rip) # 0x1b8740d a: 10 06 adc %al,(%rsi) c: 03 74 b4 01 add 0x1(%rsp,%rsi,4),%esi 10: 10 07 adc %al,(%rdi) 12: 03 74 b0 01 add 0x1(%rax,%rsi,4),%esi 16: 10 08 adc %cl,(%rax) 18: 03 74 d8 01 add 0x1(%rax,%rbx,8),%esi 1c: 00 00 add %al,(%rax) 1e: 00 00 add %al,(%rax) 20: 00 51 52 add %dl,0x52(%rcx) 23: 55 push %rbp 24: 89 e5 mov %esp,%ebp 26: 0f 34 sysenter 28: cd 80 int $0x80 * 2a: 5d pop %rbp <-- trapping instruction 2b: 5a pop %rdx 2c: 59 pop %rcx 2d: c3 retq 2e: 90 nop 2f: 90 nop 30: 90 nop 31: 90 nop 32: 8d b4 26 00 00 00 00 lea 0x0(%rsi,%riz,1),%esi 39: 8d b4 26 00 00 00 00 lea 0x0(%rsi,%riz,1),%esi