================================================================== BUG: KASAN: use-after-free in strcmp+0x90/0xb0 lib/string.c:364 Read of size 1 at addr ffff8880a1da6018 by task syz-executor.5/8625 CPU: 1 PID: 8625 Comm: syz-executor.5 Not tainted 5.8.0-rc2-syzkaller #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+0x18f/0x20d lib/dump_stack.c:118 print_address_description.constprop.0.cold+0xae/0x436 mm/kasan/report.c:383 __kasan_report mm/kasan/report.c:513 [inline] kasan_report.cold+0x1f/0x37 mm/kasan/report.c:530 strcmp+0x90/0xb0 lib/string.c:364 devlink_get_from_attrs+0x1bf/0x2f0 net/core/devlink.c:137 devlink_health_reporter_get_from_cb net/core/devlink.c:5763 [inline] devlink_nl_cmd_health_reporter_dump_get_dumpit+0x14a/0x930 net/core/devlink.c:6006 genl_lock_dumpit+0x7f/0xb0 net/netlink/genetlink.c:575 netlink_dump+0x4cd/0xf60 net/netlink/af_netlink.c:2245 __netlink_dump_start+0x643/0x900 net/netlink/af_netlink.c:2353 genl_family_rcv_msg_dumpit+0x2ac/0x310 net/netlink/genetlink.c:638 genl_family_rcv_msg net/netlink/genetlink.c:733 [inline] genl_rcv_msg+0x797/0x9e0 net/netlink/genetlink.c:753 netlink_rcv_skb+0x15a/0x430 net/netlink/af_netlink.c:2469 genl_rcv+0x24/0x40 net/netlink/genetlink.c:764 netlink_unicast_kernel net/netlink/af_netlink.c:1303 [inline] netlink_unicast+0x533/0x7d0 net/netlink/af_netlink.c:1329 netlink_sendmsg+0x856/0xd90 net/netlink/af_netlink.c:1918 sock_sendmsg_nosec net/socket.c:652 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:672 ____sys_sendmsg+0x6e8/0x810 net/socket.c:2363 ___sys_sendmsg+0xf3/0x170 net/socket.c:2417 __sys_sendmsg+0xe5/0x1b0 net/socket.c:2450 do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:359 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45cba9 Code: Bad RIP value. RSP: 002b:00007f42a4283c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00000000004fee00 RCX: 000000000045cba9 RDX: 0000000000000000 RSI: 00000000200003c0 RDI: 0000000000000007 RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000000000000944 R14: 00000000004cc188 R15: 00007f42a42846d4 Allocated by task 8627: save_stack+0x1b/0x40 mm/kasan/common.c:48 set_track mm/kasan/common.c:56 [inline] __kasan_kmalloc.constprop.0+0xc2/0xd0 mm/kasan/common.c:494 __kmalloc_reserve net/core/skbuff.c:142 [inline] __alloc_skb+0xae/0x550 net/core/skbuff.c:210 alloc_skb include/linux/skbuff.h:1083 [inline] netlink_alloc_large_skb net/netlink/af_netlink.c:1175 [inline] netlink_sendmsg+0x94f/0xd90 net/netlink/af_netlink.c:1893 sock_sendmsg_nosec net/socket.c:652 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:672 ____sys_sendmsg+0x6e8/0x810 net/socket.c:2363 ___sys_sendmsg+0xf3/0x170 net/socket.c:2417 __sys_sendmsg+0xe5/0x1b0 net/socket.c:2450 do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:359 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Freed by task 8627: save_stack+0x1b/0x40 mm/kasan/common.c:48 set_track mm/kasan/common.c:56 [inline] kasan_set_free_info mm/kasan/common.c:316 [inline] __kasan_slab_free+0xf5/0x140 mm/kasan/common.c:455 __cache_free mm/slab.c:3426 [inline] kfree+0x103/0x2c0 mm/slab.c:3757 skb_free_head net/core/skbuff.c:590 [inline] skb_release_data+0x6d9/0x910 net/core/skbuff.c:610 skb_release_all net/core/skbuff.c:664 [inline] __kfree_skb net/core/skbuff.c:678 [inline] consume_skb net/core/skbuff.c:837 [inline] consume_skb+0xc2/0x160 net/core/skbuff.c:831 netlink_unicast_kernel net/netlink/af_netlink.c:1304 [inline] netlink_unicast+0x53b/0x7d0 net/netlink/af_netlink.c:1329 netlink_sendmsg+0x856/0xd90 net/netlink/af_netlink.c:1918 sock_sendmsg_nosec net/socket.c:652 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:672 ____sys_sendmsg+0x6e8/0x810 net/socket.c:2363 ___sys_sendmsg+0xf3/0x170 net/socket.c:2417 __sys_sendmsg+0xe5/0x1b0 net/socket.c:2450 do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:359 entry_SYSCALL_64_after_hwframe+0x44/0xa9 The buggy address belongs to the object at ffff8880a1da6000 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 24 bytes inside of 512-byte region [ffff8880a1da6000, ffff8880a1da6200) The buggy address belongs to the page: page:ffffea0002876980 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 flags: 0xfffe0000000200(slab) raw: 00fffe0000000200 ffffea0002413108 ffffea00027bdfc8 ffff8880aa000a80 raw: 0000000000000000 ffff8880a1da6000 0000000100000004 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8880a1da5f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8880a1da5f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff8880a1da6000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880a1da6080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880a1da6100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================