* [syzbot ci] Re: net: Fix error handling in netdev_register_kobject
[not found] <20251107080117.15099-1-make24@iscas.ac.cn>
@ 2025-11-07 11:06 ` syzbot ci
0 siblings, 0 replies; only message in thread
From: syzbot ci @ 2025-11-07 11:06 UTC (permalink / raw)
To: akpm, atenart, davem, ebiederm, edumazet, gregkh, horms, kuba,
kuniyu, linux-kernel, make24, netdev, pabeni, sdf, stable,
yajun.deng
Cc: syzbot, syzkaller-bugs
syzbot ci has tested the following series
[v1] net: Fix error handling in netdev_register_kobject
https://lore.kernel.org/all/20251107080117.15099-1-make24@iscas.ac.cn
* [PATCH] net: Fix error handling in netdev_register_kobject
and found the following issue:
KASAN: slab-use-after-free Read in netdev_run_todo
Full report is available here:
https://ci.syzbot.org/series/29bd058e-ea85-48e2-9bb9-ff9c0214f12e
***
KASAN: slab-use-after-free Read in netdev_run_todo
tree: net-next
URL: https://kernel.googlesource.com/pub/scm/linux/kernel/git/netdev/net-next.git
base: 8a25a2e34157d882032112e4194ccdfb29c499e8
arch: amd64
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
config: https://ci.syzbot.org/builds/2f985280-f9ef-47c8-b4ec-80d44968222b/config
==================================================================
BUG: KASAN: slab-use-after-free in kobject_put+0x2ab/0x480
Read of size 1 at addr ffff888113992714 by task kworker/u8:0/12
CPU: 0 UID: 0 PID: 12 Comm: kworker/u8:0 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Workqueue: netns cleanup_net
Call Trace:
<TASK>
dump_stack_lvl+0x189/0x250
print_report+0xca/0x240
kasan_report+0x118/0x150
kobject_put+0x2ab/0x480
netdev_run_todo+0xd2e/0xea0
ops_undo_list+0x3e1/0x990
cleanup_net+0x4d8/0x820
process_scheduled_works+0xae1/0x17b0
worker_thread+0x8a0/0xda0
kthread+0x711/0x8a0
ret_from_fork+0x4bc/0x870
ret_from_fork_asm+0x1a/0x30
</TASK>
Allocated by task 5810:
kasan_save_track+0x3e/0x80
__kasan_kmalloc+0x93/0xb0
__kvmalloc_node_noprof+0x5cd/0x910
alloc_netdev_mqs+0xa6/0x11b0
ip6gre_init_net+0xb5/0x3c0
ops_init+0x35c/0x5c0
setup_net+0xfe/0x320
copy_net_ns+0x34e/0x4e0
create_new_namespaces+0x3f3/0x720
unshare_nsproxy_namespaces+0x11c/0x170
ksys_unshare+0x4c8/0x8c0
__x64_sys_unshare+0x38/0x50
do_syscall_64+0xfa/0xfa0
entry_SYSCALL_64_after_hwframe+0x77/0x7f
Freed by task 12:
kasan_save_track+0x3e/0x80
__kasan_save_free_info+0x46/0x50
__kasan_slab_free+0x5c/0x80
kfree+0x19a/0x6d0
device_release+0x9c/0x1c0
kobject_put+0x22b/0x480
netdev_run_todo+0xd0c/0xea0
ops_undo_list+0x3e1/0x990
cleanup_net+0x4d8/0x820
process_scheduled_works+0xae1/0x17b0
worker_thread+0x8a0/0xda0
kthread+0x711/0x8a0
ret_from_fork+0x4bc/0x870
ret_from_fork_asm+0x1a/0x30
The buggy address belongs to the object at ffff888113992000
which belongs to the cache kmalloc-cg-4k of size 4096
The buggy address is located 1812 bytes inside of
freed 4096-byte region [ffff888113992000, ffff888113993000)
The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x113990
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0x17ff00000000040(head|node=0|zone=2|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 017ff00000000040 ffff88810004b500 dead000000000122 0000000000000000
raw: 0000000000000000 0000000000040004 00000000f5000000 0000000000000000
head: 017ff00000000040 ffff88810004b500 dead000000000122 0000000000000000
head: 0000000000000000 0000000000040004 00000000f5000000 0000000000000000
head: 017ff00000000003 ffffea00044e6401 00000000ffffffff 00000000ffffffff
head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000008
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5810, tgid 5810 (syz-executor), ts 65154411256, free_ts 60842795356
post_alloc_hook+0x240/0x2a0
get_page_from_freelist+0x2365/0x2440
__alloc_frozen_pages_noprof+0x181/0x370
alloc_pages_mpol+0x232/0x4a0
allocate_slab+0x96/0x350
___slab_alloc+0xe94/0x18a0
__slab_alloc+0x65/0x100
__kmalloc_noprof+0x471/0x7f0
__register_sysctl_table+0x72/0x1340
__addrconf_sysctl_register+0x328/0x4c0
addrconf_sysctl_register+0x168/0x1c0
ipv6_add_dev+0xd46/0x1370
addrconf_notify+0x794/0x1010
notifier_call_chain+0x1b6/0x3e0
register_netdevice+0x1608/0x1ae0
register_netdev+0x40/0x60
page last free pid 15 tgid 15 stack trace:
__free_frozen_pages+0xbc4/0xd30
__folio_put+0x21b/0x2c0
skb_release_data+0x49a/0x7c0
napi_consume_skb+0x158/0x1e0
skb_defer_free_flush+0x18f/0x250
net_rx_action+0x804/0xe50
handle_softirqs+0x286/0x870
run_ksoftirqd+0x9b/0x100
smpboot_thread_fn+0x542/0xa60
kthread+0x711/0x8a0
ret_from_fork+0x4bc/0x870
ret_from_fork_asm+0x1a/0x30
Memory state around the buggy address:
ffff888113992600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff888113992680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888113992700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff888113992780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff888113992800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
***
If these findings have caused you to resend the series or submit a
separate fix, please add the following tag to your commit message:
Tested-by: syzbot@syzkaller.appspotmail.com
---
This report is generated by a bot. It may contain errors.
syzbot ci engineers can be reached at syzkaller@googlegroups.com.
^ permalink raw reply [flat|nested] only message in thread