==================================================================
BUG: KASAN: slab-use-after-free in __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
BUG: KASAN: slab-use-after-free in _raw_spin_lock_irqsave+0x3a/0x60 kernel/locking/spinlock.c:162
Read of size 1 at addr ffff888046be3418 by task rcu_exp_gp_kthr/18
CPU: 3 UID: 0 PID: 18 Comm: rcu_exp_gp_kthr Not tainted syzkaller #0 PREEMPT(full)
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Call Trace:
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
print_address_description mm/kasan/report.c:378 [inline]
print_report+0xcd/0x630 mm/kasan/report.c:482
kasan_report+0xe0/0x110 mm/kasan/report.c:595
__kasan_check_byte+0x36/0x50 mm/kasan/common.c:580
kasan_check_byte include/linux/kasan.h:401 [inline]
lock_acquire kernel/locking/lockdep.c:5842 [inline]
lock_acquire+0xfc/0x350 kernel/locking/lockdep.c:5825
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
_raw_spin_lock_irqsave+0x3a/0x60 kernel/locking/spinlock.c:162
p9_tag_remove net/9p/client.c:397 [inline]
p9_req_put net/9p/client.c:405 [inline]
p9_req_put+0xaf/0x250 net/9p/client.c:402
req_done+0x1dc/0x2e0 net/9p/trans_virtio.c:147
vring_interrupt drivers/virtio/virtio_ring.c:2718 [inline]
vring_interrupt+0x31e/0x400 drivers/virtio/virtio_ring.c:2693
__handle_irq_event_percpu+0x236/0x920 kernel/irq/handle.c:203
handle_irq_event_percpu kernel/irq/handle.c:240 [inline]
handle_irq_event+0xab/0x1e0 kernel/irq/handle.c:257
handle_edge_irq+0x3ca/0x9e0 kernel/irq/chip.c:855
generic_handle_irq_desc include/linux/irqdesc.h:173 [inline]
handle_irq arch/x86/kernel/irq.c:254 [inline]
call_irq_handler arch/x86/kernel/irq.c:310 [inline]
__common_interrupt+0xd0/0x2f0 arch/x86/kernel/irq.c:325
common_interrupt+0xba/0xe0 arch/x86/kernel/irq.c:318
asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:688
RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline]
RIP: 0010:csd_lock kernel/smp.c:357 [inline]
RIP: 0010:smp_call_function_single+0x42f/0x6b0 kernel/smp.c:674
Code: 48 b8 00 00 00 00 00 fc ff df 48 8b 4c 24 20 49 89 cf 83 e1 07 49 c1 ef 03 49 01 c7 8d 41 03 88 44 24 38 e8 93 f5 0b 00 f3 90 <41> 0f b6 07 38 44 24 38 7c 08 84 c0 0f 85 d4 01 00 00 8b 43 08 31
RSP: 0018:ffffc90000157ba0 EFLAGS: 00000293
RAX: 0000000000000000 RBX: ffff88806a73b580 RCX: ffffffff81b11623
RDX: ffff88801d6fc900 RSI: ffffffff81b115fd RDI: 0000000000000005
RBP: ffffc90000157cf8 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000001 R11: fffffbfff1c79e5e R12: 1ffff9200002af7c
R13: 0000000000000002 R14: 0000000000000001 R15: ffffed100d4e76b1
__sync_rcu_exp_select_node_cpus+0x597/0xd50 kernel/rcu/tree_exp.h:420
sync_rcu_exp_select_node_cpus kernel/rcu/tree_exp.h:455 [inline]
sync_rcu_exp_select_cpus+0x3cb/0xab0 kernel/rcu/tree_exp.h:522
rcu_exp_sel_wait_wake kernel/rcu/tree_exp.h:718 [inline]
wait_rcu_exp_gp+0x2c/0x40 kernel/rcu/tree_exp.h:492
kthread_worker_fn+0x310/0xc50 kernel/kthread.c:1010
kthread+0x3c5/0x780 kernel/kthread.c:463
ret_from_fork+0x675/0x7d0 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Allocated by task 11977:
kasan_save_stack+0x33/0x60 mm/kasan/common.c:56
kasan_save_track+0x14/0x30 mm/kasan/common.c:77
poison_kmalloc_redzone mm/kasan/common.c:400 [inline]
__kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:417
kmalloc_noprof include/linux/slab.h:957 [inline]
p9_client_create+0xc7/0x11d0 net/9p/client.c:985
v9fs_session_init+0x1f7/0x1a80 fs/9p/v9fs.c:410
v9fs_mount+0xc5/0xa90 fs/9p/vfs_super.c:122
legacy_get_tree+0x10c/0x220 fs/fs_context.c:663
vfs_get_tree+0x8e/0x340 fs/super.c:1751
fc_mount fs/namespace.c:1208 [inline]
do_new_mount_fc fs/namespace.c:3651 [inline]
do_new_mount fs/namespace.c:3727 [inline]
path_mount+0x7b9/0x23a0 fs/namespace.c:4037
do_mount fs/namespace.c:4050 [inline]
__do_sys_mount fs/namespace.c:4238 [inline]
__se_sys_mount fs/namespace.c:4215 [inline]
__x64_sys_mount+0x293/0x310 fs/namespace.c:4215
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
Freed by task 11977:
kasan_save_stack+0x33/0x60 mm/kasan/common.c:56
kasan_save_track+0x14/0x30 mm/kasan/common.c:77
__kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:587
kasan_save_free_info mm/kasan/kasan.h:406 [inline]
poison_slab_object mm/kasan/common.c:252 [inline]
__kasan_slab_free+0x5f/0x80 mm/kasan/common.c:284
kasan_slab_free include/linux/kasan.h:234 [inline]
slab_free_hook mm/slub.c:2539 [inline]
slab_free mm/slub.c:6630 [inline]
kfree+0x2b8/0x6d0 mm/slub.c:6837
p9_client_create+0xa28/0x11d0 net/9p/client.c:1064
v9fs_session_init+0x1f7/0x1a80 fs/9p/v9fs.c:410
v9fs_mount+0xc5/0xa90 fs/9p/vfs_super.c:122
legacy_get_tree+0x10c/0x220 fs/fs_context.c:663
vfs_get_tree+0x8e/0x340 fs/super.c:1751
fc_mount fs/namespace.c:1208 [inline]
do_new_mount_fc fs/namespace.c:3651 [inline]
do_new_mount fs/namespace.c:3727 [inline]
path_mount+0x7b9/0x23a0 fs/namespace.c:4037
do_mount fs/namespace.c:4050 [inline]
__do_sys_mount fs/namespace.c:4238 [inline]
__se_sys_mount fs/namespace.c:4215 [inline]
__x64_sys_mount+0x293/0x310 fs/namespace.c:4215
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
The buggy address belongs to the object at ffff888046be3400
which belongs to the cache kmalloc-512 of size 512
The buggy address is located 24 bytes inside of
freed 512-byte region [ffff888046be3400, ffff888046be3600)
The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x46be0
head: order:2 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
anon flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000040 ffff88801b442c80 0000000000000000 dead000000000001
raw: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000
head: 00fff00000000040 ffff88801b442c80 0000000000000000 dead000000000001
head: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000
head: 00fff00000000002 ffffea00011af801 00000000ffffffff 00000000ffffffff
head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000004
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 2, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5958, tgid 5958 (syz-executor), ts 98690225570, free_ts 98558368657
set_page_owner include/linux/page_owner.h:32 [inline]
post_alloc_hook+0x1c0/0x230 mm/page_alloc.c:1850
prep_new_page mm/page_alloc.c:1858 [inline]
get_page_from_freelist+0x10a3/0x3a30 mm/page_alloc.c:3884
__alloc_frozen_pages_noprof+0x25f/0x2470 mm/page_alloc.c:5183
alloc_pages_mpol+0x1fb/0x550 mm/mempolicy.c:2416
alloc_slab_page mm/slub.c:3055 [inline]
allocate_slab mm/slub.c:3228 [inline]
new_slab+0x24a/0x360 mm/slub.c:3282
___slab_alloc+0xdae/0x1a60 mm/slub.c:4651
__slab_alloc.constprop.0+0x63/0x110 mm/slub.c:4770
__slab_alloc_node mm/slub.c:4846 [inline]
slab_alloc_node mm/slub.c:5268 [inline]
__do_kmalloc_node mm/slub.c:5641 [inline]
__kmalloc_noprof+0x501/0x880 mm/slub.c:5654
kmalloc_noprof include/linux/slab.h:961 [inline]
kzalloc_noprof include/linux/slab.h:1094 [inline]
fib6_info_alloc+0x40/0x160 net/ipv6/ip6_fib.c:155
ip6_route_info_create+0x14c/0x870 net/ipv6/route.c:3809
ip6_route_add.part.0+0x22/0x1d0 net/ipv6/route.c:3938
ip6_route_add+0x45/0x60 net/ipv6/route.c:3935
addrconf_prefix_route+0x2fd/0x510 net/ipv6/addrconf.c:2488
inet6_addr_add+0x589/0x960 net/ipv6/addrconf.c:3053
inet6_rtm_newaddr+0x1619/0x1c70 net/ipv6/addrconf.c:5059
rtnetlink_rcv_msg+0x95e/0xe90 net/core/rtnetlink.c:6951
page last free pid 5349 tgid 5349 stack trace:
reset_page_owner include/linux/page_owner.h:25 [inline]
free_pages_prepare mm/page_alloc.c:1394 [inline]
__free_frozen_pages+0x7df/0x1160 mm/page_alloc.c:2906
discard_slab mm/slub.c:3326 [inline]
__put_partials+0x130/0x170 mm/slub.c:3872
qlink_free mm/kasan/quarantine.c:163 [inline]
qlist_free_all+0x4d/0x120 mm/kasan/quarantine.c:179
kasan_quarantine_reduce+0x195/0x1e0 mm/kasan/quarantine.c:286
__kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:352
kasan_slab_alloc include/linux/kasan.h:252 [inline]
slab_post_alloc_hook mm/slub.c:4970 [inline]
slab_alloc_node mm/slub.c:5280 [inline]
kmem_cache_alloc_node_noprof+0x28a/0x770 mm/slub.c:5332
__alloc_skb+0x2b2/0x380 net/core/skbuff.c:660
alloc_skb include/linux/skbuff.h:1383 [inline]
netlink_alloc_large_skb+0x69/0x140 net/netlink/af_netlink.c:1186
netlink_sendmsg+0x698/0xdd0 net/netlink/af_netlink.c:1871
sock_sendmsg_nosec net/socket.c:727 [inline]
__sock_sendmsg net/socket.c:742 [inline]
____sys_sendmsg+0xa98/0xc70 net/socket.c:2630
___sys_sendmsg+0x134/0x1d0 net/socket.c:2684
__sys_sendmsg+0x16d/0x220 net/socket.c:2716
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
Memory state around the buggy address:
ffff888046be3300: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff888046be3380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff888046be3400: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff888046be3480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff888046be3500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
----------------
Code disassembly (best guess):
0: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax
7: fc ff df
a: 48 8b 4c 24 20 mov 0x20(%rsp),%rcx
f: 49 89 cf mov %rcx,%r15
12: 83 e1 07 and $0x7,%ecx
15: 49 c1 ef 03 shr $0x3,%r15
19: 49 01 c7 add %rax,%r15
1c: 8d 41 03 lea 0x3(%rcx),%eax
1f: 88 44 24 38 mov %al,0x38(%rsp)
23: e8 93 f5 0b 00 call 0xbf5bb
28: f3 90 pause
* 2a: 41 0f b6 07 movzbl (%r15),%eax <-- trapping instruction
2e: 38 44 24 38 cmp %al,0x38(%rsp)
32: 7c 08 jl 0x3c
34: 84 c0 test %al,%al
36: 0f 85 d4 01 00 00 jne 0x210
3c: 8b 43 08 mov 0x8(%rbx),%eax
3f: 31 .byte 0x31