syzbot


WARNING in __alloc_skb (3)

Status: fixed on 2024/03/29 01:33
Subsystems: ppp
[Documentation on labels]
Fix commit: cb88cb53badb ppp_async: limit MRU to 64K
First crash: 69d, last: 69d
Discussions (2)
Title Replies (including bot) Last reply
[PATCH net] ppp_async: limit MRU to 64K 3 (3) 2024/02/07 03:00
[PATCH net] ppp_async: limit MRU to 64K 2 (2) 2024/02/05 18:59
Similar bugs (3)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream WARNING in __alloc_skb arm-msm net C error 24 1132d 1144d 20/26 fixed on 2021/04/09 19:46
linux-6.1 WARNING in __alloc_skb origin:upstream C done 2 158d 158d 3/3 fixed on 2023/12/11 10:30
upstream WARNING in __alloc_skb (2) ppp C done 2 140d 154d 25/26 fixed on 2024/01/20 21:18
Last patch testing requests (1)
Created Duration User Patch Repo Result
2024/02/05 11:24 2h02m edumazet@google.com patch git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci OK log

Sample crash report:
------------[ cut here ]------------
WARNING: CPU: 1 PID: 11 at mm/page_alloc.c:4543 __alloc_pages+0x308/0x698 mm/page_alloc.c:4543
Modules linked in:
CPU: 1 PID: 11 Comm: kworker/u4:0 Not tainted 6.8.0-rc2-syzkaller-g41bccc98fb79 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023
Workqueue: events_unbound flush_to_ldisc
pstate: 204000c5 (nzCv daIF +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : __alloc_pages+0x308/0x698 mm/page_alloc.c:4543
lr : __alloc_pages+0xc8/0x698 mm/page_alloc.c:4537
sp : ffff800093967580
x29: ffff800093967660 x28: ffff8000939675a0 x27: dfff800000000000
x26: ffff70001272ceb4 x25: 0000000000000000 x24: ffff8000939675c0
x23: 0000000000000000 x22: 0000000000060820 x21: 1ffff0001272ceb8
x20: ffff8000939675e0 x19: 0000000000000010 x18: ffff800093967120
x17: ffff800083bded5c x16: ffff80008ac97500 x15: 0000000000000005
x14: 1ffff0001272cebc x13: 0000000000000000 x12: 0000000000000000
x11: ffff70001272cec1 x10: 1ffff0001272cec0 x9 : 0000000000000001
x8 : ffff800091c91000 x7 : 0000000000000000 x6 : 000000000000003f
x5 : 00000000ffffffff x4 : 0000000000000000 x3 : 0000000000000020
x2 : 0000000000000008 x1 : 0000000000000000 x0 : ffff8000939675e0
Call trace:
 __alloc_pages+0x308/0x698 mm/page_alloc.c:4543
 __alloc_pages_node include/linux/gfp.h:238 [inline]
 alloc_pages_node include/linux/gfp.h:261 [inline]
 __kmalloc_large_node+0xbc/0x1fc mm/slub.c:3926
 __do_kmalloc_node mm/slub.c:3969 [inline]
 __kmalloc_node_track_caller+0x418/0x620 mm/slub.c:4001
 kmalloc_reserve+0x17c/0x23c net/core/skbuff.c:590
 __alloc_skb+0x1c8/0x3d8 net/core/skbuff.c:651
 __netdev_alloc_skb+0xb8/0x3e8 net/core/skbuff.c:715
 netdev_alloc_skb include/linux/skbuff.h:3235 [inline]
 dev_alloc_skb include/linux/skbuff.h:3248 [inline]
 ppp_async_input drivers/net/ppp/ppp_async.c:863 [inline]
 ppp_asynctty_receive+0x588/0x186c drivers/net/ppp/ppp_async.c:341
 tty_ldisc_receive_buf+0x12c/0x15c drivers/tty/tty_buffer.c:390
 tty_port_default_receive_buf+0x74/0xac drivers/tty/tty_port.c:37
 receive_buf drivers/tty/tty_buffer.c:444 [inline]
 flush_to_ldisc+0x284/0x6e4 drivers/tty/tty_buffer.c:494
 process_one_work+0x694/0x1204 kernel/workqueue.c:2633
 process_scheduled_works kernel/workqueue.c:2706 [inline]
 worker_thread+0x938/0xef4 kernel/workqueue.c:2787
 kthread+0x288/0x310 kernel/kthread.c:388
 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:860
irq event stamp: 68080
hardirqs last  enabled at (68079): [<ffff80008ae4d110>] __raw_spin_unlock_irq include/linux/spinlock_api_smp.h:159 [inline]
hardirqs last  enabled at (68079): [<ffff80008ae4d110>] _raw_spin_unlock_irq+0x30/0x80 kernel/locking/spinlock.c:202
hardirqs last disabled at (68080): [<ffff80008ae4ceb0>] __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:108 [inline]
hardirqs last disabled at (68080): [<ffff80008ae4ceb0>] _raw_spin_lock_irqsave+0x2c/0x7c kernel/locking/spinlock.c:162
softirqs last  enabled at (66910): [<ffff80008002189c>] softirq_handle_end kernel/softirq.c:399 [inline]
softirqs last  enabled at (66910): [<ffff80008002189c>] __do_softirq+0xac8/0xce4 kernel/softirq.c:582
softirqs last disabled at (66019): [<ffff80008002ab48>] ____do_softirq+0x14/0x20 arch/arm64/kernel/irq.c:81
---[ end trace 0000000000000000 ]---
PPPasync: no memory (input pkt)

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/02/05 06:52 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 41bccc98fb79 a67b2c42 .config console log report syz C [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 WARNING in __alloc_skb
2024/02/05 06:19 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 41bccc98fb79 a67b2c42 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 WARNING in __alloc_skb
* Struck through repros no longer work on HEAD.