Hello, syzbot found the following issue on: HEAD commit: 70701b83e208 tcp: Fix uninitialized access in skb frags ar.. git tree: net console output: https://syzkaller.appspot.com/x/log.txt?x=1654c32ab00000 kernel config: https://syzkaller.appspot.com/x/.config?x=a262045c4c15a9e0 dashboard link: https://syzkaller.appspot.com/bug?extid=9111d2255a9710e87562 compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2 Unfortunately, I don't have any reproducer for this issue yet. IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+9111d2255a9710e87562@xxxxxxxxxxxxxxxxxxxxxxxxx general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007] CPU: 0 PID: 6744 Comm: syz-executor.0 Not tainted 5.15.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:nla_get_u32 include/net/netlink.h:1554 [inline] RIP: 0010:nldev_stat_set_mode_doit drivers/infiniband/core/nldev.c:1909 [inline] RIP: 0010:nldev_stat_set_doit+0x578/0x10d0 drivers/infiniband/core/nldev.c:2040 Code: fa 4c 8b a4 24 f8 02 00 00 48 b8 00 00 00 00 00 fc ff df c7 84 24 80 00 00 00 00 00 00 00 49 8d 7c 24 04 48 89 fa 48 c1 ea 03 <0f> b6 14 02 48 89 f8 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 02 RSP: 0018:ffffc90004acf2e8 EFLAGS: 00010247 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffc90002b94000 RDX: 0000000000000000 RSI: ffffffff8684c5ff RDI: 0000000000000004 RBP: ffff88807cda4000 R08: 0000000000000000 R09: ffff888023fb8027 R10: ffffffff8684c5d7 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000001 R14: ffff888041024280 R15: ffff888031ade780 FS: 00007eff9dddd700(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2ef24000 CR3: 0000000036902000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> rdma_nl_rcv_msg+0x36d/0x690 drivers/infiniband/core/netlink.c:195 rdma_nl_rcv_skb drivers/infiniband/core/netlink.c:239 [inline] rdma_nl_rcv+0x2ee/0x430 drivers/infiniband/core/netlink.c:259 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline] netlink_unicast+0x533/0x7d0 net/netlink/af_netlink.c:1345 netlink_sendmsg+0x86d/0xda0 net/netlink/af_netlink.c:1916 sock_sendmsg_nosec net/socket.c:704 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:724 ____sys_sendmsg+0x6e8/0x810 net/socket.c:2409 ___sys_sendmsg+0xf3/0x170 net/socket.c:2463 __sys_sendmsg+0xe5/0x1b0 net/socket.c:2492 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7effa0867ae9 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:00007eff9dddd188 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007effa097af60 RCX: 00007effa0867ae9 RDX: 0000000000000000 RSI: 0000000020000040 RDI: 0000000000000003 RBP: 00007effa08c1f6d R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffc008a753f R14: 00007eff9dddd300 R15: 0000000000022000 </TASK> Modules linked in: ---[ end trace bacb470dc6c820de ]--- RIP: 0010:nla_get_u32 include/net/netlink.h:1554 [inline] RIP: 0010:nldev_stat_set_mode_doit drivers/infiniband/core/nldev.c:1909 [inline] RIP: 0010:nldev_stat_set_doit+0x578/0x10d0 drivers/infiniband/core/nldev.c:2040 Code: fa 4c 8b a4 24 f8 02 00 00 48 b8 00 00 00 00 00 fc ff df c7 84 24 80 00 00 00 00 00 00 00 49 8d 7c 24 04 48 89 fa 48 c1 ea 03 <0f> b6 14 02 48 89 f8 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 02 RSP: 0018:ffffc90004acf2e8 EFLAGS: 00010247 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffc90002b94000 RDX: 0000000000000000 RSI: ffffffff8684c5ff RDI: 0000000000000004 RBP: ffff88807cda4000 R08: 0000000000000000 R09: ffff888023fb8027 R10: ffffffff8684c5d7 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000001 R14: ffff888041024280 R15: ffff888031ade780 FS: 00007eff9dddd700(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2ef24000 CR3: 0000000036902000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 ---------------- Code disassembly (best guess): 0: fa cli 1: 4c 8b a4 24 f8 02 00 mov 0x2f8(%rsp),%r12 8: 00 9: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax 10: fc ff df 13: c7 84 24 80 00 00 00 movl $0x0,0x80(%rsp) 1a: 00 00 00 00 1e: 49 8d 7c 24 04 lea 0x4(%r12),%rdi 23: 48 89 fa mov %rdi,%rdx 26: 48 c1 ea 03 shr $0x3,%rdx * 2a: 0f b6 14 02 movzbl (%rdx,%rax,1),%edx <-- trapping instruction 2e: 48 89 f8 mov %rdi,%rax 31: 83 e0 07 and $0x7,%eax 34: 83 c0 03 add $0x3,%eax 37: 38 d0 cmp %dl,%al 39: 7c 08 jl 0x43 3b: 84 d2 test %dl,%dl 3d: 0f .byte 0xf 3e: 85 02 test %eax,(%rdx) --- This report is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at syzkaller@xxxxxxxxxxxxxxxx. syzbot will keep track of this issue. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
