syzbot


BUG: unable to handle kernel NULL pointer dereference in bond_xdp_xmit (2)

Status: upstream: reported on 2025/03/12 05:19
Reported-by: syzbot+de2d44312a2707cc57e7@syzkaller.appspotmail.com
First crash: 94d, last: 16d
Similar bugs (2)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.1 BUG: unable to handle kernel NULL pointer dereference in bond_xdp_xmit origin:lts-only C inconclusive 241 9h45m 414d 0/3 upstream: reported C repro on 2024/04/25 19:36
linux-5.15 BUG: unable to handle kernel NULL pointer dereference in bond_xdp_xmit 5 241d 301d 0/3 auto-obsoleted due to no activity on 2025/01/23 16:27

Sample crash report:
BUG: kernel NULL pointer dereference, address: 0000000000000000
#PF: supervisor instruction fetch in kernel mode
#PF: error_code(0x0010) - not-present page
PGD 7a77a067 P4D 7a77a067 PUD 0 
Oops: 0010 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 8767 Comm: syz.3.911 Not tainted 5.15.184-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:0x0
Code: Unable to access opcode bytes at RIP 0xffffffffffffffd6.
RSP: 0018:ffffc90003d4f618 EFLAGS: 00010246
RAX: 1ffffffff163e41f RBX: 0000000000000000 RCX: 0000000000000001
RDX: ffffc90003d4f6c0 RSI: 0000000000000001 RDI: ffff888061578000
RBP: ffffc90003d4f730 R08: dffffc0000000000 R09: ffffed100c2af008
R10: ffffed100c2af008 R11: 1ffff1100c2af007 R12: ffffffff8b1f20f8
R13: dffffc0000000000 R14: ffff888061578000 R15: ffffe8ffffd46a88
FS:  00007fbd4e7786c0(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd6 CR3: 000000001e7f2000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 bond_xdp_xmit+0x282/0x420 drivers/net/bonding/bond_main.c:5228
 bq_xmit_all+0xbb1/0xf60 kernel/bpf/devmap.c:391
 __dev_flush+0xbf/0x1b0 kernel/bpf/devmap.c:421
 xdp_do_flush+0xa/0x20 net/core/filter.c:3985
 tun_build_skb drivers/net/tun.c:1703 [inline]
 tun_get_user+0x297c/0x38d0 drivers/net/tun.c:1797
 tun_chr_write_iter+0x112/0x1e0 drivers/net/tun.c:2019
 call_write_iter include/linux/fs.h:2172 [inline]
 new_sync_write fs/read_write.c:507 [inline]
 vfs_write+0x712/0xd00 fs/read_write.c:594
 ksys_write+0x14d/0x250 fs/read_write.c:647
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7fbd5090f41f
Code: 89 54 24 18 48 89 74 24 10 89 7c 24 08 e8 f9 92 02 00 48 8b 54 24 18 48 8b 74 24 10 41 89 c0 8b 7c 24 08 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 31 44 89 c7 48 89 44 24 08 e8 4c 93 02 00 48
RSP: 002b:00007fbd4e778000 EFLAGS: 00000293 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007fbd50b37fa0 RCX: 00007fbd5090f41f
RDX: 0000000000000082 RSI: 0000200000000640 RDI: 00000000000000c8
RBP: 00007fbd50992ab1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000082 R11: 0000000000000293 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fbd50b37fa0 R15: 00007ffc6f3c20c8
 </TASK>
Modules linked in:
CR2: 0000000000000000
---[ end trace 37ec6bc4fe3f7387 ]---
RIP: 0010:0x0
Code: Unable to access opcode bytes at RIP 0xffffffffffffffd6.
RSP: 0018:ffffc90003d4f618 EFLAGS: 00010246
RAX: 1ffffffff163e41f RBX: 0000000000000000 RCX: 0000000000000001
RDX: ffffc90003d4f6c0 RSI: 0000000000000001 RDI: ffff888061578000
RBP: ffffc90003d4f730 R08: dffffc0000000000 R09: ffffed100c2af008
R10: ffffed100c2af008 R11: 1ffff1100c2af007 R12: ffffffff8b1f20f8
R13: dffffc0000000000 R14: ffff888061578000 R15: ffffe8ffffd46a88
FS:  00007fbd4e7786c0(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd6 CR3: 000000001e7f2000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400

Crashes (7):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/05/28 23:05 linux-5.15.y 98f47d0e9b8c 3d2f584d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan BUG: unable to handle kernel NULL pointer dereference in bond_xdp_xmit
2025/04/29 00:53 linux-5.15.y f7347f400572 aeb6ec69 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan BUG: unable to handle kernel NULL pointer dereference in bond_xdp_xmit
2025/04/24 11:02 linux-5.15.y f7347f400572 9882047a .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan BUG: unable to handle kernel NULL pointer dereference in bond_xdp_xmit
2025/04/03 23:03 linux-5.15.y 0c935c049b5c d7ae3a11 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan BUG: unable to handle kernel NULL pointer dereference in bond_xdp_xmit
2025/03/26 08:19 linux-5.15.y 0c935c049b5c 89d30d73 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan BUG: unable to handle kernel NULL pointer dereference in bond_xdp_xmit
2025/03/18 19:35 linux-5.15.y 0c935c049b5c 22a6c2b1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan BUG: unable to handle kernel NULL pointer dereference in bond_xdp_xmit
2025/03/12 05:18 linux-5.15.y c16c81c81336 ee70e6db .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan BUG: unable to handle kernel NULL pointer dereference in bond_xdp_xmit
* Struck through repros no longer work on HEAD.