Re: [syzbot] WARNING in batadv_nc_mesh_free

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue: general protection fault in batadv_nc_purge_paths

RBP: 00007fe7b40631d0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000002 R13: 00007ffe7ffd3def R14: 00007fe7b4063300 R15: 0000000000022000 general protection fault, probably for non-canonical address 0xdffffc0000000002: 0000 [#1] PREEMPT SMP KASAN KASAN: null-ptr-deref in range [0x0000000000000010-0x0000000000000017] CPU: 1 PID: 9061 Comm: syz-executor.0 Not tainted 5.15.0-rc6-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:batadv_nc_purge_paths+0x38/0x3f0 net/batman-adv/network-coding.c:437 Code: 48 89 d3 49 89 f6 48 89 7c 24 58 49 bd 00 00 00 00 00 fc ff df e8 38 48 ab f7 4d 8d 7e 10 4c 89 f8 48 c1 e8 03 48 89 44 24 48 <42> 8a 04 28 84 c0 0f 85 88 03 00 00 41 8b 2f 31 ff 89 ee e8 20 4c RSP: 0018:ffffc9000d04eac0 EFLAGS: 00010202 RAX: 0000000000000002 RBX: 0000000000000000 RCX: ffff888078270000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff88807ec2cc80 RBP: 00000000fffffff4 R08: ffffffff8154e5b4 R09: ffffed100fd85adc R10: ffffed100fd85adc R11: 0000000000000000 R12: ffff88807ec2cc80 R13: dffffc0000000000 R14: 0000000000000000 R15: 0000000000000010 FS: 00007fe7b4063700(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f359172e000 CR3: 000000005e749000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: batadv_nc_mesh_free+0x7a/0xf0 net/batman-adv/network-coding.c:1869 batadv_mesh_free+0x6f/0x140 net/batman-adv/main.c:249 batadv_mesh_init+0x5b1/0x620 net/batman-adv/main.c:230 batadv_softif_init_late+0x8fe/0xd70 net/batman-adv/soft-interface.c:804 register_netdevice+0x826/0x1c30 net/core/dev.c:10229 __rtnl_newlink net/core/rtnetlink.c:3458 [inline] rtnl_newlink+0x14b3/0x1d10 net/core/rtnetlink.c:3506 rtnetlink_rcv_msg+0x934/0xe60 net/core/rtnetlink.c:5572 netlink_rcv_skb+0x200/0x470 net/netlink/af_netlink.c:2510 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline] netlink_unicast+0x814/0x9f0 net/netlink/af_netlink.c:1345 netlink_sendmsg+0xa29/0xe50 net/netlink/af_netlink.c:1935 sock_sendmsg_nosec net/socket.c:704 [inline] sock_sendmsg net/socket.c:724 [inline] ____sys_sendmsg+0x5b9/0x910 net/socket.c:2409 ___sys_sendmsg net/socket.c:2463 [inline] __sys_sendmsg+0x36f/0x450 net/socket.c:2492 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7fe7b48eda39 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:00007fe7b4063188 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007fe7b49f0f60 RCX: 00007fe7b48eda39 RDX: 0000000000000000 RSI: 0000000020000140 RDI: 0000000000000003 RBP: 00007fe7b40631d0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000002 R13: 00007ffe7ffd3def R14: 00007fe7b4063300 R15: 0000000000022000 Modules linked in: ---[ end trace 67ff054734964acf ]--- RIP: 0010:batadv_nc_purge_paths+0x38/0x3f0 net/batman-adv/network-coding.c:437 Code: 48 89 d3 49 89 f6 48 89 7c 24 58 49 bd 00 00 00 00 00 fc ff df e8 38 48 ab f7 4d 8d 7e 10 4c 89 f8 48 c1 e8 03 48 89 44 24 48 <42> 8a 04 28 84 c0 0f 85 88 03 00 00 41 8b 2f 31 ff 89 ee e8 20 4c RSP: 0018:ffffc9000d04eac0 EFLAGS: 00010202 RAX: 0000000000000002 RBX: 0000000000000000 RCX: ffff888078270000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff88807ec2cc80 RBP: 00000000fffffff4 R08: ffffffff8154e5b4 R09: ffffed100fd85adc R10: ffffed100fd85adc R11: 0000000000000000 R12: ffff88807ec2cc80 R13: dffffc0000000000 R14: 0000000000000000 R15: 0000000000000010 FS: 00007fe7b4063700(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fc230f87020 CR3: 000000005e749000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 ---------------- Code disassembly (best guess): 0: 48 89 d3 mov %rdx,%rbx 3: 49 89 f6 mov %rsi,%r14 6: 48 89 7c 24 58 mov %rdi,0x58(%rsp) b: 49 bd 00 00 00 00 00 movabs $0xdffffc0000000000,%r13 12: fc ff df 15: e8 38 48 ab f7 callq 0xf7ab4852 1a: 4d 8d 7e 10 lea 0x10(%r14),%r15 1e: 4c 89 f8 mov %r15,%rax 21: 48 c1 e8 03 shr $0x3,%rax 25: 48 89 44 24 48 mov %rax,0x48(%rsp) * 2a: 42 8a 04 28 mov (%rax,%r13,1),%al <-- trapping instruction 2e: 84 c0 test %al,%al 30: 0f 85 88 03 00 00 jne 0x3be 36: 41 8b 2f mov (%r15),%ebp 39: 31 ff xor %edi,%edi 3b: 89 ee mov %ebp,%esi 3d: e8 .byte 0xe8 3e: 20 .byte 0x20 3f: 4c rex.WR

Tested on:

commit: 1d4590f5 Merge tag 'acpi-5.15-rc7' of git://git.kernel.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=156e86c4b00000 kernel config: https://syzkaller.appspot.com/x/.config?x=d95853dad8472c91 dashboard link: https://syzkaller.appspot.com/bug?extid=28b0702ada0bf7381f58 compiler: Debian clang version 11.0.1-2, GNU ld (GNU Binutils for Debian) 2.35.2 patch: https://syzkaller.appspot.com/x/patch.diff?x=16cb3daf300000