Hello, syzbot has tested the proposed patch but the reproducer is still triggering an issue: general protection fault in macvlan_get_link_net
general protection fault, probably for non-canonical address 0xdffffc00000000b3: 0000 [#1] PREEMPT SMP KASAN KASAN: null-ptr-deref in range [0x0000000000000598-0x000000000000059f] CPU: 0 PID: 8229 Comm: syz-executor.0 Not tainted 5.8.0-rc4-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:read_pnet include/net/net_namespace.h:330 [inline] RIP: 0010:dev_net include/linux/netdevice.h:2261 [inline] RIP: 0010:macvlan_get_link_net+0x43/0x60 drivers/net/macvlan.c:1667 Code: c6 f0 0b 00 00 4c 89 f0 48 c1 e8 03 42 80 3c 38 00 74 08 4c 89 f7 e8 dc cb d6 fc bb 98 05 00 00 49 03 1e 48 89 d8 48 c1 e8 03 <42> 80 3c 38 00 74 08 48 89 df e8 be cb d6 fc 48 8b 03 5b 41 5e 41 RSP: 0018:ffffc90004e47110 EFLAGS: 00010202 RAX: 00000000000000b3 RBX: 0000000000000598 RCX: ffff88808f57c040 RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffff888089dc8000 RBP: ffffc90004e47228 R08: ffffffff866c14ae R09: fffffbfff12b7531 R10: fffffbfff12b7531 R11: 0000000000000000 R12: 1ffff110113b904b R13: ffff888089dc825f R14: ffff888089dc8bf0 R15: dffffc0000000000 FS: 00007f40720ea700(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005623955cb160 CR3: 000000009dc8e000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: rtnl_fill_link_netnsid net/core/rtnetlink.c:1569 [inline] rtnl_fill_ifinfo+0x3355/0x4650 net/core/rtnetlink.c:1758 rtmsg_ifinfo_build_skb+0xe2/0x180 net/core/rtnetlink.c:3706 rollback_registered_many+0xc9b/0x14a0 net/core/dev.c:8972 unregister_netdevice_many+0x46/0x260 net/core/dev.c:10113 __rtnl_newlink net/core/rtnetlink.c:3381 [inline] rtnl_newlink+0x1876/0x1c10 net/core/rtnetlink.c:3398 rtnetlink_rcv_msg+0x889/0xd40 net/core/rtnetlink.c:5461 netlink_rcv_skb+0x190/0x3a0 net/netlink/af_netlink.c:2469 netlink_unicast_kernel net/netlink/af_netlink.c:1303 [inline] netlink_unicast+0x786/0x940 net/netlink/af_netlink.c:1329 netlink_sendmsg+0xa57/0xd70 net/netlink/af_netlink.c:1918 sock_sendmsg_nosec net/socket.c:652 [inline] sock_sendmsg net/socket.c:672 [inline] ____sys_sendmsg+0x519/0x800 net/socket.c:2352 ___sys_sendmsg net/socket.c:2406 [inline] __sys_sendmsg+0x2b1/0x360 net/socket.c:2439 do_syscall_64+0x73/0xe0 arch/x86/entry/common.c:384 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45cb99 Code: Bad RIP value. RSP: 002b:00007f40720e9c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 0000000000502680 RCX: 000000000045cb99 RDX: 0000000000000000 RSI: 0000000020000080 RDI: 0000000000000006 RBP: 000000000078bfa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000000000000a40 R14: 00000000004cd2f6 R15: 00007f40720ea6d4 Modules linked in: ---[ end trace 45c7e0a1442252cb ]--- RIP: 0010:read_pnet include/net/net_namespace.h:330 [inline] RIP: 0010:dev_net include/linux/netdevice.h:2261 [inline] RIP: 0010:macvlan_get_link_net+0x43/0x60 drivers/net/macvlan.c:1667 Code: c6 f0 0b 00 00 4c 89 f0 48 c1 e8 03 42 80 3c 38 00 74 08 4c 89 f7 e8 dc cb d6 fc bb 98 05 00 00 49 03 1e 48 89 d8 48 c1 e8 03 <42> 80 3c 38 00 74 08 48 89 df e8 be cb d6 fc 48 8b 03 5b 41 5e 41 RSP: 0018:ffffc90004e47110 EFLAGS: 00010202 RAX: 00000000000000b3 RBX: 0000000000000598 RCX: ffff88808f57c040 RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffff888089dc8000 RBP: ffffc90004e47228 R08: ffffffff866c14ae R09: fffffbfff12b7531 R10: fffffbfff12b7531 R11: 0000000000000000 R12: 1ffff110113b904b R13: ffff888089dc825f R14: ffff888089dc8bf0 R15: dffffc0000000000 FS: 00007f40720ea700(0000) GS:ffff8880ae900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005623955cb160 CR3: 000000009dc8e000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Tested on: commit: 9506a941 net: fix a race condition in dev_get_iflink() git tree: https://github.com/congwang/linux.git net console output: https://syzkaller.appspot.com/x/log.txt?x=1569d430900000 kernel config: https://syzkaller.appspot.com/x/.config?x=b1a5a263f7a540cb dashboard link: https://syzkaller.appspot.com/bug?extid=95eec132c4bd9b1d8430 compiler: clang version 10.0.0 (https://github.com/llvm/llvm-project/ c2443155a0fb245c8f17f2c1c72b6ea391e86e81)
