Hello,
syzbot found the following issue on:
HEAD commit: 1b4ef5214f17 Linux 6.6.124
git tree: linux-6.6.y
console output:
https://syzkaller.appspot.com/x/log.txt?x=17af6e5a580000
kernel config:
https://syzkaller.appspot.com/x/.config?x=2a950bf7c0bff9f9
dashboard link:
https://syzkaller.appspot.com/bug?extid=6fca2b584268f3142fb2
compiler: Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8
Unfortunately, I don't have any reproducer for this issue yet.
Downloadable assets:
disk image:
https://storage.googleapis.com/syzbot-assets/054222c95938/disk-1b4ef521.raw.xz
vmlinux:
https://storage.googleapis.com/syzbot-assets/bf3f638dea81/vmlinux-1b4ef521.xz
kernel image:
https://storage.googleapis.com/syzbot-assets/ba2200fbe5c9/bzImage-1b4ef521.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by:
syzbot+6fca2b...@syzkaller.appspotmail.com
==================================================================
BUG: KASAN: slab-out-of-bounds in fib6_add_rt2node net/ipv6/ip6_fib.c:1140 [inline]
BUG: KASAN: slab-out-of-bounds in fib6_add+0x4680/0x46e0 net/ipv6/ip6_fib.c:1503
Read of size 1 at addr ffff88802638d0ce by task syz.8.5128/24221
CPU: 0 PID: 24221 Comm: syz.8.5128 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026
Call Trace:
<TASK>
dump_stack_lvl+0x18c/0x250 lib/dump_stack.c:106
print_address_description mm/kasan/report.c:364 [inline]
print_report+0xa8/0x210 mm/kasan/report.c:468
kasan_report+0x117/0x150 mm/kasan/report.c:581
fib6_add_rt2node net/ipv6/ip6_fib.c:1140 [inline]
fib6_add+0x4680/0x46e0 net/ipv6/ip6_fib.c:1503
__ip6_ins_rt net/ipv6/route.c:1352 [inline]
ip6_route_add+0x8a/0x160 net/ipv6/route.c:3903
inet6_rtm_newroute+0x2ba/0x1c90 net/ipv6/route.c:5567
rtnetlink_rcv_msg+0x869/0xfa0 net/core/rtnetlink.c:6472
netlink_rcv_skb+0x241/0x4d0 net/netlink/af_netlink.c:2545
netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline]
netlink_unicast+0x751/0x8d0 net/netlink/af_netlink.c:1346
netlink_sendmsg+0x8d0/0xbf0 net/netlink/af_netlink.c:1894
sock_sendmsg_nosec net/socket.c:730 [inline]
__sock_sendmsg net/socket.c:745 [inline]
____sys_sendmsg+0x5ba/0x960 net/socket.c:2594
___sys_sendmsg+0x2a6/0x360 net/socket.c:2648
__sys_sendmsg net/socket.c:2677 [inline]
__do_sys_sendmsg net/socket.c:2686 [inline]
__se_sys_sendmsg+0x1c2/0x2b0 net/socket.c:2684
do_syscall_x64 arch/x86/entry/common.c:46 [inline]
do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f445e79bf79
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f445f5a3028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f445ea15fa0 RCX: 00007f445e79bf79
RDX: 0000000000000000 RSI: 0000200000004380 RDI: 0000000000000004
RBP: 00007f445e8327e0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f445ea16038 R14: 00007f445ea15fa0 R15: 00007ffc73d78b88
</TASK>
Allocated by task 11867:
kasan_save_stack mm/kasan/common.c:46 [inline]
kasan_set_track+0x4e/0x70 mm/kasan/common.c:53
____kasan_kmalloc mm/kasan/common.c:375 [inline]
__kasan_kmalloc+0x8f/0xa0 mm/kasan/common.c:384
kasan_kmalloc include/linux/kasan.h:198 [inline]
__do_kmalloc_node mm/slab_common.c:1007 [inline]
__kmalloc+0xb4/0x230 mm/slab_common.c:1020
kmalloc include/linux/slab.h:604 [inline]
kzalloc include/linux/slab.h:721 [inline]
fib6_info_alloc+0x30/0xf0 net/ipv6/ip6_fib.c:155
ip6_route_info_create+0x44f/0x1240 net/ipv6/route.c:3803
ip6_route_add+0x28/0x160 net/ipv6/route.c:3899
inet6_rtm_newroute+0x2ba/0x1c90 net/ipv6/route.c:5567
rtnetlink_rcv_msg+0x869/0xfa0 net/core/rtnetlink.c:6472
netlink_rcv_skb+0x241/0x4d0 net/netlink/af_netlink.c:2545
netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline]
netlink_unicast+0x751/0x8d0 net/netlink/af_netlink.c:1346
netlink_sendmsg+0x8d0/0xbf0 net/netlink/af_netlink.c:1894
sock_sendmsg_nosec net/socket.c:730 [inline]
__sock_sendmsg net/socket.c:745 [inline]
____sys_sendmsg+0x5ba/0x960 net/socket.c:2594
___sys_sendmsg+0x2a6/0x360 net/socket.c:2648
__sys_sendmsg net/socket.c:2677 [inline]
__do_sys_sendmsg net/socket.c:2686 [inline]
__se_sys_sendmsg+0x1c2/0x2b0 net/socket.c:2684
do_syscall_x64 arch/x86/entry/common.c:46 [inline]
do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2
Last potentially related work creation:
kasan_save_stack+0x3e/0x60 mm/kasan/common.c:46
__kasan_record_aux_stack+0xaf/0xc0 mm/kasan/generic.c:492
insert_work+0x3d/0x310 kernel/workqueue.c:1651
__queue_work+0xc39/0x1020 kernel/workqueue.c:1800
queue_work_on+0x128/0x1f0 kernel/workqueue.c:1835
queue_work include/linux/workqueue.h:562 [inline]
netdevice_queue_work drivers/infiniband/core/roce_gid_mgmt.c:658 [inline]
netdevice_event+0x793/0x8e0 drivers/infiniband/core/roce_gid_mgmt.c:801
notifier_call_chain+0x197/0x380 kernel/notifier.c:93
call_netdevice_notifiers_extack net/core/dev.c:2077 [inline]
call_netdevice_notifiers net/core/dev.c:2091 [inline]
dev_set_mac_address+0x39a/0x4d0 net/core/dev.c:8961
alb_set_slave_mac_addr+0x1bd/0x2e0 drivers/net/bonding/bond_alb.c:1038
bond_alb_set_mac_address+0xba3/0x10e0 drivers/net/bonding/bond_alb.c:1818
bond_set_mac_address+0xfb/0x800 drivers/net/bonding/bond_main.c:4817
dev_set_mac_address+0x312/0x4d0 net/core/dev.c:8956
dev_set_mac_address_user+0x31/0x50 net/core/dev.c:8975
do_setlink+0x7ac/0x4130 net/core/rtnetlink.c:2860
rtnl_setlink+0x3d9/0x4e0 net/core/rtnetlink.c:3208
rtnetlink_rcv_msg+0x869/0xfa0 net/core/rtnetlink.c:6472
netlink_rcv_skb+0x241/0x4d0 net/netlink/af_netlink.c:2545
netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline]
netlink_unicast+0x751/0x8d0 net/netlink/af_netlink.c:1346
netlink_sendmsg+0x8d0/0xbf0 net/netlink/af_netlink.c:1894
sock_sendmsg_nosec net/socket.c:730 [inline]
__sock_sendmsg net/socket.c:745 [inline]
____sys_sendmsg+0x5ba/0x960 net/socket.c:2594
___sys_sendmsg+0x2a6/0x360 net/socket.c:2648
__sys_sendmsg net/socket.c:2677 [inline]
__do_sys_sendmsg net/socket.c:2686 [inline]
__se_sys_sendmsg+0x1c2/0x2b0 net/socket.c:2684
do_syscall_x64 arch/x86/entry/common.c:46 [inline]
do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2
Second to last potentially related work creation:
kasan_save_stack+0x3e/0x60 mm/kasan/common.c:46
__kasan_record_aux_stack+0xaf/0xc0 mm/kasan/generic.c:492
kvfree_call_rcu+0xee/0x790 kernel/rcu/tree.c:3452
ip6mr_net_exit_batch+0x4a/0x90 net/ipv6/ip6mr.c:1376
ops_exit_list net/core/net_namespace.c:178 [inline]
cleanup_net+0x795/0xbb0 net/core/net_namespace.c:652
process_one_work kernel/workqueue.c:2634 [inline]
process_scheduled_works+0xa5d/0x15d0 kernel/workqueue.c:2711
worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
The buggy address belongs to the object at ffff88802638d000
which belongs to the cache kmalloc-192 of size 192
The buggy address is located 22 bytes to the right of
allocated 184-byte region [ffff88802638d000, ffff88802638d0b8)
The buggy address belongs to the physical page:
page:ffffea000098e340 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x2638d
flags: 0xfff00000000800(slab|node=0|zone=1|lastcpupid=0x7ff)
page_type: 0xffffffff()
raw: 00fff00000000800 ffff888017c41a00 ffffea00012376c0 dead000000000004
raw: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x12c00(GFP_NOIO|__GFP_NOWARN|__GFP_NORETRY), pid 23, tgid 23 (kworker/1:0), ts 12878510928, free_ts 12443003415
set_page_owner include/linux/page_owner.h:31 [inline]
post_alloc_hook+0x1c1/0x200 mm/page_alloc.c:1581
prep_new_page mm/page_alloc.c:1588 [inline]
get_page_from_freelist+0x1951/0x19e0 mm/page_alloc.c:3220
__alloc_pages+0x1f0/0x460 mm/page_alloc.c:4486
alloc_slab_page+0x5d/0x160 mm/slub.c:1881
allocate_slab mm/slub.c:2028 [inline]
new_slab+0x87/0x2d0 mm/slub.c:2081
___slab_alloc+0xc5d/0x12f0 mm/slub.c:3253
__slab_alloc mm/slub.c:3339 [inline]
__slab_alloc_node mm/slub.c:3392 [inline]
slab_alloc_node mm/slub.c:3485 [inline]
__kmem_cache_alloc_node+0x19e/0x250 mm/slub.c:3534
__do_kmalloc_node mm/slab_common.c:1006 [inline]
__kmalloc+0xa4/0x230 mm/slab_common.c:1020
kmalloc include/linux/slab.h:604 [inline]
usb_alloc_urb+0x46/0x140 drivers/usb/core/urb.c:75
usb_internal_control_msg drivers/usb/core/message.c:96 [inline]
usb_control_msg+0x119/0x3e0 drivers/usb/core/message.c:154
get_port_status drivers/usb/core/hub.c:609 [inline]
hub_ext_port_status+0x103/0x6d0 drivers/usb/core/hub.c:626
usb_hub_port_status drivers/usb/core/hub.c:648 [inline]
hub_activate+0x77b/0x1a60 drivers/usb/core/hub.c:1159
process_one_work kernel/workqueue.c:2634 [inline]
process_scheduled_works+0xa5d/0x15d0 kernel/workqueue.c:2711
worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
page last free stack trace:
reset_page_owner include/linux/page_owner.h:24 [inline]
free_pages_prepare mm/page_alloc.c:1181 [inline]
free_unref_page_prepare+0x7b2/0x8c0 mm/page_alloc.c:2365
free_unref_page+0x32/0x2e0 mm/page_alloc.c:2458
vfree+0x1a6/0x320 mm/vmalloc.c:2868
delayed_vfree_work+0x55/0x80 mm/vmalloc.c:2788
process_one_work kernel/workqueue.c:2634 [inline]
process_scheduled_works+0xa5d/0x15d0 kernel/workqueue.c:2711
worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
Memory state around the buggy address:
ffff88802638cf80: 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc fc
ffff88802638d000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff88802638d080: 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc fc
^
ffff88802638d100: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff88802638d180: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
==================================================================
---
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