R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
R13: 00007ffcaf24ae2f R14: 00007f197ec78300 R15: 0000000000022000
================================================
WARNING: lock held when returning to user space!
6.18.0-rc7-next-20251128 #1 Not tainted
------------------------------------------------
syz-executor.7/13805 is leaving the kernel with locks still held!
1 lock held by syz-executor.7/13805:
#0: ffff88800abd8f08 (&sb->s_type->i_mutex_key#31/1){+.+.}-{4:4}, at: start_creating_noperm+0x84/0xd0
FAULT_INJECTION: forcing a failure.
name failslab, interval 1, probability 0, space 0, times 0
CPU: 1 UID: 0 PID: 13813 Comm: syz-executor.5 Not tainted 6.18.0-rc7-next-20251128 #1 PREEMPT(voluntary)
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014
Call Trace:
dump_stack_lvl+0xfa/0x120
should_fail_ex+0x4d7/0x5e0
should_failslab+0xc2/0x120
__kmalloc_noprof+0xd6/0x830
genl_family_rcv_msg_attrs_parse.constprop.0+0xdb/0x290
genl_family_rcv_msg_doit+0xab/0x2f0
genl_rcv_msg+0x532/0x7e0
netlink_rcv_skb+0x147/0x430
genl_rcv+0x28/0x40
netlink_unicast+0x5a7/0x870
netlink_sendmsg+0x8a3/0xd80
____sys_sendmsg+0xa34/0xbf0
___sys_sendmsg+0x10f/0x1b0
__sys_sendmsg+0x150/0x200
do_syscall_64+0xbf/0x420
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f1981702b19
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f197ec78188 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f1981815f60 RCX: 00007f1981702b19
RDX: 0000000000000000 RSI: 0000000020000380 RDI: 0000000000000005
RBP: 00007f197ec781d0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
R13: 00007ffcaf24ae2f R14: 00007f197ec78300 R15: 0000000000022000
netlink: 112 bytes leftover after parsing attributes in process `syz-executor.3'.
netlink: 112 bytes leftover after parsing attributes in process `syz-executor.3'.
netlink: 112 bytes leftover after parsing attributes in process `syz-executor.3'.
==================================================================
BUG: KASAN: slab-use-after-free in rwsem_down_write_slowpath+0x1522/0x1670
Read of size 4 at addr ffff88804b245374 by task syz-executor.6/13851
CPU: 1 UID: 0 PID: 13851 Comm: syz-executor.6 Not tainted 6.18.0-rc7-next-20251128 #1 PREEMPT(voluntary)
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014
Call Trace:
dump_stack_lvl+0xca/0x120
print_report+0xcb/0x610
kasan_report+0xca/0x100
rwsem_down_write_slowpath+0x1522/0x1670
down_write_nested+0x1c6/0x1f0
start_creating_noperm+0x84/0xd0
do_mq_open+0x25f/0x980
__x64_sys_mq_open+0x14f/0x1e0
do_syscall_64+0xbf/0x420
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f913d883b19
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f913adf9188 EFLAGS: 00000246 ORIG_RAX: 00000000000000f0
RAX: ffffffffffffffda RBX: 00007f913d996f60 RCX: 00007f913d883b19
RDX: 0000000000000198 RSI: 0000000000000080 RDI: 0000000020000040
RBP: 00007f913d8ddf6d R08: 0000000000000000 R09: 0000000000000000
R10: 0000000020000080 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fff87d7b8ff R14: 00007f913adf9300 R15: 0000000000022000
Allocated by task 13833:
kasan_save_stack+0x24/0x50
kasan_save_track+0x14/0x30
__kasan_slab_alloc+0x59/0x70
kmem_cache_alloc_node_noprof+0x228/0x730
copy_process+0x460/0x7230
kernel_clone+0xea/0x7c0
__do_sys_clone+0xce/0x120
do_syscall_64+0xbf/0x420
entry_SYSCALL_64_after_hwframe+0x77/0x7f
Freed by task 22:
kasan_save_stack+0x24/0x50
kasan_save_track+0x14/0x30
kasan_save_free_info+0x3a/0x60
__kasan_slab_free+0x43/0x70
kmem_cache_free+0x2cd/0x660
rcu_core+0x73c/0x1ed0
handle_softirqs+0x1b1/0x740
run_ksoftirqd+0x2e/0x60
smpboot_thread_fn+0x41d/0x9d0
kthread+0x3c8/0x740
ret_from_fork+0x67a/0x7a0
ret_from_fork_asm+0x1a/0x30
Last potentially related work creation:
kasan_save_stack+0x24/0x50
kasan_record_aux_stack+0x89/0xa0
__call_rcu_common.constprop.0+0x70/0xad0
delayed_put_task_struct+0xde/0x230
rcu_core+0x73c/0x1ed0
handle_softirqs+0x1b1/0x740
do_softirq+0x48/0x80
__local_bh_enable_ip+0xf1/0x110
kernel_fpu_end+0x5e/0x70
crc32c+0x2d0/0x350
ext4_handle_dirty_dirblock+0x15e/0x230
ext4_delete_entry+0x34c/0x430
__ext4_unlink+0x7b2/0xce0
ext4_unlink+0x42e/0x540
vfs_unlink+0x44a/0xb50
do_unlinkat+0x361/0x620
__x64_sys_unlink+0xc7/0x110
do_syscall_64+0xbf/0x420
entry_SYSCALL_64_after_hwframe+0x77/0x7f
Second to last potentially related work creation:
kasan_save_stack+0x24/0x50
kasan_record_aux_stack+0x89/0xa0
__call_rcu_common.constprop.0+0x70/0xad0
put_task_struct_rcu_user+0x75/0xc0
__schedule+0x1003/0x46a0
schedule+0xdb/0x390
do_nanosleep+0x15e/0x570
hrtimer_nanosleep+0x1a9/0x500
common_nsleep+0xaa/0xd0
__x64_sys_clock_nanosleep+0x331/0x470
do_syscall_64+0xbf/0x420
entry_SYSCALL_64_after_hwframe+0x77/0x7f
The buggy address belongs to the object at ffff88804b245340
which belongs to the cache task_struct of size 6848
The buggy address is located 52 bytes inside of
freed 6848-byte region [ffff88804b245340, ffff88804b246e00)
The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x4b240
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
memcg:ffff8880168f0101
anon flags: 0x100000000000040(head|node=0|zone=1)
page_type: f5(slab)
raw: 0100000000000040 ffff88800944c640 0000000000000000 dead000000000001
raw: 0000000000000000 0000000000040004 00000000f5000000 ffff8880168f0101
head: 0100000000000040 ffff88800944c640 0000000000000000 dead000000000001
head: 0000000000000000 0000000000040004 00000000f5000000 ffff8880168f0101
head: 0100000000000003 ffffea00012c9001 00000000ffffffff 00000000ffffffff
head: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000008
page dumped because: kasan: bad access detected
Memory state around the buggy address:
ffff88804b245200: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc
ffff88804b245280: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff88804b245300: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb
^
ffff88804b245380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff88804b245400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
netlink: 112 bytes leftover after parsing attributes in process `syz-executor.7'.