syzbot


kernel BUG in pskb_expand_head

Status: upstream: reported C repro on 2025/07/23 19:00
Bug presence: origin:lts
[Documentation on labels]
Reported-by: syzbot+30e65637741adeefd34e@syzkaller.appspotmail.com
First crash: 4d02h, last: 3d04h
Bug presence (2)
Date Name Commit Repro Result
2025/07/25 lts (merge base) c79648372d02 C [report] kernel BUG in pskb_expand_head
2025/07/25 upstream (ToT) 2942242dde89 C Didn't crash
Similar bugs (9)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-5.15 kernel BUG in pskb_expand_head (2) origin:lts-only -1 C 4 2d22h 9d06h 0/3 upstream: reported C repro on 2025/07/18 14:25
android-6-1 kernel BUG in pskb_expand_head -1 1 781d 781d 0/2 auto-obsoleted due to no activity on 2023/09/05 19:11
upstream kernel BUG in pskb_expand_head (4) intel-wired-lan -1 1 150d 150d 28/29 fixed on 2025/06/10 16:19
upstream kernel BUG in pskb_expand_head (3) net -1 1 399d 399d 0/29 closed as invalid on 2024/09/04 18:07
upstream kernel BUG in pskb_expand_head (2) bpf net -1 10 794d 809d 0/29 auto-obsoleted due to no activity on 2023/08/23 09:08
linux-5.15 kernel BUG in pskb_expand_head -1 1 833d 833d 0/3 auto-obsoleted due to no activity on 2023/08/14 13:19
upstream kernel BUG in llc_sap_action_send_xid_c net -1 C error 61 1356d 1570d 20/29 fixed on 2021/11/10 00:50
upstream kernel BUG in pskb_expand_head net -1 C done 1600 899d 1350d 22/29 fixed on 2023/02/25 08:02
linux-6.1 kernel BUG in pskb_expand_head -1 1 789d 789d 0/3 auto-obsoleted due to no activity on 2023/09/07 17:22

Sample crash report:
------------[ cut here ]------------
kernel BUG at net/core/skbuff.c:1727!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 39 Comm: kworker/1:1 Not tainted 5.15.189-syzkaller-00079-ga71626bd56a5 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Workqueue: events sk_psock_backlog
RIP: 0010:pskb_expand_head+0x11a5/0x11d0 net/core/skbuff.c:1727
Code: 44 89 e1 80 e1 07 80 c1 03 38 c1 0f 8c de f3 ff ff 4c 89 e7 e8 8c 9a f6 fd e9 d1 f3 ff ff e8 42 22 b8 fd 0f 0b e8 3b 22 b8 fd <0f> 0b 48 8b 4d d0 80 e1 07 80 c1 03 38 c1 0f 8c b2 fa ff ff 48 8b
RSP: 0018:ffffc9000028fa08 EFLAGS: 00010293
RAX: ffffffff83b08d95 RBX: dffffc0000000000 RCX: ffff8881087813c0
RDX: 0000000000000000 RSI: 0000000000000002 RDI: 0000000000000001
RBP: ffffc9000028faa8 R08: dffffc0000000000 R09: ffffed102484a936
R10: ffffed102484a936 R11: 1ffff1102484a935 R12: 0000000000000e80
R13: 0000000000000000 R14: 0000000000000002 R15: 0000000000008080
FS:  0000000000000000(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000009000 CR3: 0000000124255000 CR4: 00000000003506a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 __pskb_pull_tail+0xb1/0x1480 net/core/skbuff.c:2281
 __skb_linearize include/linux/skbuff.h:3529 [inline]
 skb_linearize include/linux/skbuff.h:3541 [inline]
 sk_psock_skb_ingress_enqueue+0x67/0x410 net/core/skmsg.c:539
 sk_psock_skb_ingress net/core/skmsg.c:583 [inline]
 sk_psock_handle_skb net/core/skmsg.c:621 [inline]
 sk_psock_backlog+0xa72/0x1230 net/core/skmsg.c:686
 process_one_work+0x6be/0xba0 kernel/workqueue.c:2325
 worker_thread+0xa59/0x1200 kernel/workqueue.c:2472
 kthread+0x411/0x500 kernel/kthread.c:337
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>
Modules linked in:
---[ end trace d96cb1e586f4c800 ]---
RIP: 0010:pskb_expand_head+0x11a5/0x11d0 net/core/skbuff.c:1727
Code: 44 89 e1 80 e1 07 80 c1 03 38 c1 0f 8c de f3 ff ff 4c 89 e7 e8 8c 9a f6 fd e9 d1 f3 ff ff e8 42 22 b8 fd 0f 0b e8 3b 22 b8 fd <0f> 0b 48 8b 4d d0 80 e1 07 80 c1 03 38 c1 0f 8c b2 fa ff ff 48 8b
RSP: 0018:ffffc9000028fa08 EFLAGS: 00010293
RAX: ffffffff83b08d95 RBX: dffffc0000000000 RCX: ffff8881087813c0
RDX: 0000000000000000 RSI: 0000000000000002 RDI: 0000000000000001
RBP: ffffc9000028faa8 R08: dffffc0000000000 R09: ffffed102484a936
R10: ffffed102484a936 R11: 1ffff1102484a935 R12: 0000000000000e80
R13: 0000000000000000 R14: 0000000000000002 R15: 0000000000008080
FS:  0000000000000000(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000009000 CR3: 000000010d253000 CR4: 00000000003506a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400

Crashes (6):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/07/23 20:31 android13-5.15-lts a71626bd56a5 e1dd4f22 .config strace log report syz / log C [disk image] [vmlinux] [kernel image] ci2-android-5-15-perf kernel BUG in pskb_expand_head
2025/07/23 19:40 android13-5.15-lts a71626bd56a5 e1dd4f22 .config strace log report syz / log C [disk image] [vmlinux] [kernel image] ci2-android-5-15-perf kernel BUG in pskb_expand_head
2025/07/23 18:56 android13-5.15-lts a71626bd56a5 e1dd4f22 .config strace log report syz / log C [disk image] [vmlinux] [kernel image] ci2-android-5-15-perf kernel BUG in pskb_expand_head
2025/07/24 15:49 android13-5.15-lts a71626bd56a5 65d60d73 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15-perf kernel BUG in pskb_expand_head
2025/07/24 06:15 android13-5.15-lts a71626bd56a5 0c1d6ded .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15-perf kernel BUG in pskb_expand_head
2025/07/23 18:10 android13-5.15-lts a71626bd56a5 e1dd4f22 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15-perf kernel BUG in pskb_expand_head
* Struck through repros no longer work on HEAD.