EXT4-fs warning (device sda): ext4_resize_begin:81: There are errors in the filesystem, so online resizing is not allowed ================================================ WARNING: lock held when returning to user space! 6.18.0-rc7-next-20251127 #1 Not tainted ------------------------------------------------ syz-executor.3/27315 is leaving the kernel with locks still held! 1 lock held by syz-executor.3/27315: #0: ffff88801bd71c88 (&sb->s_type->i_mutex_key#24/1){+.+.}-{4:4}, at: start_creating_noperm+0x84/0xd0 kauditd_printk_skb: 85 callbacks suppressed audit: type=1326 audit(1764259509.112:3482): auid=0 uid=0 gid=0 ses=4 subj=system_u:system_r:kernel_t:s0 pid=27328 comm="syz-executor.6" exe="/syz-executor.6" sig=0 arch=c000003e syscall=202 compat=0 ip=0x7f2ec75e7b19 code=0x7ffc0000 audit: type=1326 audit(1764259509.114:3483): auid=0 uid=0 gid=0 ses=4 subj=system_u:system_r:kernel_t:s0 pid=27328 comm="syz-executor.6" exe="/syz-executor.6" sig=0 arch=c000003e syscall=16 compat=0 ip=0x7f2ec75e7b19 code=0x7ffc0000 audit: type=1326 audit(1764259509.114:3484): auid=0 uid=0 gid=0 ses=4 subj=system_u:system_r:kernel_t:s0 pid=27328 comm="syz-executor.6" exe="/syz-executor.6" sig=0 arch=c000003e syscall=202 compat=0 ip=0x7f2ec75e7b19 code=0x7ffc0000 audit: type=1326 audit(1764259509.114:3485): auid=0 uid=0 gid=0 ses=4 subj=system_u:system_r:kernel_t:s0 pid=27328 comm="syz-executor.6" exe="/syz-executor.6" sig=0 arch=c000003e syscall=202 compat=0 ip=0x7f2ec75e7b19 code=0x7ffc0000 ================================================================== BUG: KASAN: slab-use-after-free in rwsem_down_write_slowpath+0x1522/0x1670 Read of size 4 at addr ffff88801e6c37b4 by task syz-executor.3/27340 audit: type=1326 audit(1764259509.129:3486): auid=0 uid=0 gid=0 ses=4 subj=system_u:system_r:kernel_t:s0 pid=27328 comm="syz-executor.6" exe="/syz-executor.6" sig=0 arch=c000003e syscall=85 compat=0 ip=0x7f2ec75e7b19 code=0x7ffc0000 CPU: 1 UID: 0 PID: 27340 Comm: syz-executor.3 Not tainted 6.18.0-rc7-next-20251127 #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: 0033:0x7fdf11c07b19 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:00007fdf0f17d188 EFLAGS: 00000246 ORIG_RAX: 00000000000000f0 RAX: ffffffffffffffda RBX: 00007fdf11d1af60 RCX: 00007fdf11c07b19 RDX: 0000000000000104 RSI: 0000000000000000 RDI: 0000000020000080 RBP: 00007fdf11c61f6d R08: 0000000000000000 R09: 0000000000000000 R10: 00000000200000c0 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffd3d02b70f R14: 00007fdf0f17d300 R15: 0000000000022000 audit: type=1326 audit(1764259509.132:3487): auid=0 uid=0 gid=0 ses=4 subj=system_u:system_r:kernel_t:s0 pid=27328 comm="syz-executor.6" exe="/syz-executor.6" sig=0 arch=c000003e syscall=202 compat=0 ip=0x7f2ec75e7b19 code=0x7ffc0000 Allocated by task 27307: kasan_save_stack+0x24/0x50 audit: type=1326 audit(1764259509.138:3488): auid=0 uid=0 gid=0 ses=4 subj=system_u:system_r:kernel_t:s0 pid=27328 comm="syz-executor.6" exe="/syz-executor.6" sig=0 arch=c000003e syscall=304 compat=0 ip=0x7f2ec75e7b19 code=0x7ffc0000 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 99: 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 __irq_exit_rcu+0xc4/0x100 irq_exit_rcu+0x9/0x20 sysvec_apic_timer_interrupt+0x70/0x80 asm_sysvec_apic_timer_interrupt+0x1a/0x20 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 __irq_exit_rcu+0xc4/0x100 irq_exit_rcu+0x9/0x20 sysvec_apic_timer_interrupt+0x70/0x80 asm_sysvec_apic_timer_interrupt+0x1a/0x20 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 __cond_resched+0x4c/0x80 __mutex_lock+0xc5/0x2090 sched_mm_cid_exit+0x9a/0x450 do_exit+0x2db/0x2950 do_group_exit+0xd3/0x2a0 __x64_sys_exit_group+0x3e/0x50 x64_sys_call+0x18d6/0x18e0 do_syscall_64+0xbf/0x420 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff88801e6c3780 which belongs to the cache task_struct of size 6848 The buggy address is located 52 bytes inside of freed 6848-byte region [ffff88801e6c3780, ffff88801e6c5240) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1e6c0 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 memcg:ffff88800d1f5f81 flags: 0x100000000000040(head|node=0|zone=1) page_type: f5(slab) raw: 0100000000000040 ffff88800944c640 ffffea00013c9800 dead000000000002 raw: 0000000000000000 0000000000040004 00000000f5000000 ffff88800d1f5f81 head: 0100000000000040 ffff88800944c640 ffffea00013c9800 dead000000000002 head: 0000000000000000 0000000000040004 00000000f5000000 ffff88800d1f5f81 head: 0100000000000003 ffffea000079b001 00000000ffffffff 00000000ffffffff head: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000008 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88801e6c3680: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88801e6c3700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff88801e6c3780: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88801e6c3800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88801e6c3880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== audit: type=1326 audit(1764259509.151:3489): auid=0 uid=0 gid=0 ses=4 subj=system_u:system_r:kernel_t:s0 pid=27336 comm="syz-executor.3" exe="/syz-executor.3" sig=0 arch=c000003e syscall=202 compat=0 ip=0x7fdf11c07b19 code=0x7ffc0000 audit: type=1326 audit(1764259509.152:3490): auid=0 uid=0 gid=0 ses=4 subj=system_u:system_r:kernel_t:s0 pid=27336 comm="syz-executor.3" exe="/syz-executor.3" sig=0 arch=c000003e syscall=202 compat=0 ip=0x7fdf11c07b19 code=0x7ffc0000 audit: type=1326 audit(1764259509.154:3491): auid=0 uid=0 gid=0 ses=4 subj=system_u:system_r:kernel_t:s0 pid=27336 comm="syz-executor.3" exe="/syz-executor.3" sig=0 arch=c000003e syscall=240 compat=0 ip=0x7fdf11c07b19 code=0x7ffc0000