================================================================== BUG: KASAN: slab-out-of-bounds in legacy_parse_param+0x4c1/0x720 fs/fs_context.c:603 Write of size 1 at addr ffff8881ee785000 by task syz-executor.5/31224 CPU: 0 PID: 31224 Comm: syz-executor.5 Not tainted 5.4.147-syzkaller-00015-g5b673be0c6b0 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x18e/0x1de lib/dump_stack.c:118 print_address_description+0x9b/0x650 mm/kasan/report.c:384 __kasan_report+0x182/0x260 mm/kasan/report.c:516 kasan_report+0x30/0x60 mm/kasan/common.c:653 check_memory_region_inline mm/kasan/generic.c:141 [inline] check_memory_region+0x2a5/0x2e0 mm/kasan/generic.c:191 memcpy+0x38/0x50 mm/kasan/common.c:124 legacy_parse_param+0x4c1/0x720 fs/fs_context.c:603 vfs_parse_fs_param+0x20f/0x430 fs/fs_context.c:145 vfs_fsconfig_locked fs/fsopen.c:265 [inline] __do_sys_fsconfig fs/fsopen.c:445 [inline] __se_sys_fsconfig+0xc6b/0xf40 fs/fsopen.c:314 do_syscall_64+0xcb/0x1e0 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x7f9259b05e99 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f9258c5b168 EFLAGS: 00000246 ORIG_RAX: 00000000000001af RAX: ffffffffffffffda RBX: 00007f9259c19030 RCX: 00007f9259b05e99 RDX: 0000000020000100 RSI: 0000000000000001 RDI: 0000000000000003 RBP: 00007f9259b5fff1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000020000140 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fff403b9f7f R14: 00007f9258c5b300 R15: 0000000000022000 Allocated by task 31223: save_stack mm/kasan/common.c:70 [inline] set_track mm/kasan/common.c:78 [inline] __kasan_kmalloc+0x137/0x1e0 mm/kasan/common.c:529 kmem_cache_alloc_trace+0x139/0x2b0 mm/slub.c:2849 kmalloc include/linux/slab.h:556 [inline] legacy_parse_param+0x421/0x720 fs/fs_context.c:596 vfs_parse_fs_param+0x20f/0x430 fs/fs_context.c:145 vfs_fsconfig_locked fs/fsopen.c:265 [inline] __do_sys_fsconfig fs/fsopen.c:445 [inline] __se_sys_fsconfig+0xc6b/0xf40 fs/fsopen.c:314 do_syscall_64+0xcb/0x1e0 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Freed by task 28036: save_stack mm/kasan/common.c:70 [inline] set_track mm/kasan/common.c:78 [inline] kasan_set_free_info mm/kasan/common.c:345 [inline] __kasan_slab_free+0x18a/0x240 mm/kasan/common.c:487 slab_free_hook mm/slub.c:1455 [inline] slab_free_freelist_hook+0x7b/0x150 mm/slub.c:1493 slab_free mm/slub.c:3073 [inline] kfree+0xe0/0x660 mm/slub.c:4064 skb_release_all net/core/skbuff.c:675 [inline] __kfree_skb+0x55/0x170 net/core/skbuff.c:689 skb_free_datagram+0x24/0xd0 net/core/datagram.c:329 netlink_recvmsg+0x5ce/0x1060 net/netlink/af_netlink.c:1999 sock_recvmsg_nosec net/socket.c:872 [inline] sock_recvmsg net/socket.c:890 [inline] __sys_recvfrom+0x31d/0x490 net/socket.c:1999 __do_sys_recvfrom net/socket.c:2017 [inline] __se_sys_recvfrom net/socket.c:2013 [inline] __x64_sys_recvfrom+0xda/0xf0 net/socket.c:2013 do_syscall_64+0xcb/0x1e0 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x44/0xa9 The buggy address belongs to the object at ffff8881ee784000 which belongs to the cache kmalloc-4k of size 4096 The buggy address is located 0 bytes to the right of 4096-byte region [ffff8881ee784000, ffff8881ee785000) The buggy address belongs to the page: page:ffffea0007b9e000 refcount:1 mapcount:0 mapping:ffff8881f5c0c280 index:0x0 compound_mapcount: 0 flags: 0x8000000000010200(slab|head) raw: 8000000000010200 0000000000000000 0000000100000001 ffff8881f5c0c280 raw: 0000000000000000 0000000080040004 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC) set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook mm/page_alloc.c:2165 [inline] prep_new_page+0x19a/0x380 mm/page_alloc.c:2171 get_page_from_freelist+0x550/0x8b0 mm/page_alloc.c:3794 __alloc_pages_nodemask+0x2d6/0x740 mm/page_alloc.c:4855 alloc_slab_page+0x39/0x3e0 mm/slub.c:343 allocate_slab mm/slub.c:1676 [inline] new_slab+0x97/0x460 mm/slub.c:1742 new_slab_objects mm/slub.c:2499 [inline] ___slab_alloc+0x330/0x4c0 mm/slub.c:2660 __slab_alloc mm/slub.c:2700 [inline] slab_alloc_node mm/slub.c:2785 [inline] slab_alloc mm/slub.c:2830 [inline] kmem_cache_alloc_trace+0x199/0x2b0 mm/slub.c:2847 kmalloc include/linux/slab.h:556 [inline] kzalloc include/linux/slab.h:690 [inline] snmp6_alloc_dev net/ipv6/addrconf.c:350 [inline] ipv6_add_dev+0x4d1/0x1480 net/ipv6/addrconf.c:399 addrconf_notify+0x57a/0x38d0 net/ipv6/addrconf.c:3524 notifier_call_chain kernel/notifier.c:98 [inline] __raw_notifier_call_chain kernel/notifier.c:399 [inline] raw_notifier_call_chain+0x9e/0x110 kernel/notifier.c:406 call_netdevice_notifiers_info net/core/dev.c:1670 [inline] call_netdevice_notifiers_extack net/core/dev.c:1682 [inline] call_netdevice_notifiers net/core/dev.c:1696 [inline] register_netdevice+0xdc8/0x12f0 net/core/dev.c:9196 register_netdev+0x37/0x50 net/core/dev.c:9294 sit_init_net+0x225/0x460 net/ipv6/sit.c:1866 ops_init+0x26e/0x340 net/core/net_namespace.c:137 __register_pernet_operations net/core/net_namespace.c:1146 [inline] register_pernet_operations+0x25c/0x8e0 net/core/net_namespace.c:1223 register_pernet_device+0x2f/0x80 net/core/net_namespace.c:1310 page_owner free stack trace missing Memory state around the buggy address: ffff8881ee784f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff8881ee784f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff8881ee785000: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff8881ee785080: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8881ee785100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================