SELinux: security_context_str_to_sid (root,errors=continue) failed with errno=-22 ================================================================== BUG: KASAN: slab-use-after-free in __fput+0xaae/0xb50 Read of size 8 at addr ffff88804d8b54f8 by task syz-executor.6/4625 CPU: 1 UID: 0 PID: 4625 Comm: syz-executor.6 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 SELinux: security_context_str_to_sid (root,errors=continue) failed with errno=-22 __fput+0xaae/0xb50 task_work_run+0x172/0x280 do_exit+0x856/0x2950 do_group_exit+0xd3/0x2a0 get_signal+0x24aa/0x25d0 arch_do_signal_or_restart+0x80/0x7a0 exit_to_user_mode_loop+0x92/0x4d0 do_syscall_64+0x3c3/0x420 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fdb2969db19 Code: Unable to access opcode bytes at 0x7fdb2969daef. RSP: 002b:00007fdb26c13218 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 00007fdb297b0f68 RCX: 00007fdb2969db19 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fdb297b0f68 RBP: 00007fdb297b0f60 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fdb297b0f6c R13: 00007ffc02f498af R14: 00007fdb26c13300 R15: 0000000000022000 Allocated by task 4625: kasan_save_stack+0x24/0x50 kasan_save_track+0x14/0x30 __kasan_slab_alloc+0x59/0x70 kmem_cache_alloc_lru_noprof+0x217/0x720 __d_alloc+0x34/0xa10 d_alloc+0x4a/0x1e0 lookup_one_qstr_excl+0x174/0x270 start_creating_noperm+0x94/0xd0 do_mq_open+0x25f/0x980 __x64_sys_mq_open+0x14f/0x1e0 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 dentry_free+0xc3/0x160 __dentry_kill+0x498/0x5f0 finish_dput+0x75/0x430 dput.part.0+0x43f/0x530 dput+0x1f/0x30 __fput+0x515/0xb50 task_work_run+0x172/0x280 do_exit+0x856/0x2950 do_group_exit+0xd3/0x2a0 get_signal+0x24aa/0x25d0 arch_do_signal_or_restart+0x80/0x7a0 exit_to_user_mode_loop+0x92/0x4d0 do_syscall_64+0x3c3/0x420 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff88804d8b5490 which belongs to the cache dentry of size 312 The buggy address is located 104 bytes inside of freed 312-byte region [ffff88804d8b5490, ffff88804d8b55c8) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x4d8b4 head: order:1 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 memcg:ffff88801f7b1201 flags: 0x100000000000040(head|node=0|zone=1) page_type: f5(slab) raw: 0100000000000040 ffff888009462280 dead000000000122 0000000000000000 raw: 0000000000000000 0000000080150015 00000000f5000000 ffff88801f7b1201 head: 0100000000000040 ffff888009462280 dead000000000122 0000000000000000 head: 0000000000000000 0000000080150015 00000000f5000000 ffff88801f7b1201 head: 0100000000000001 ffffea0001362d01 00000000ffffffff 00000000ffffffff head: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000002 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88804d8b5380: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff88804d8b5400: 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc >ffff88804d8b5480: fc fc fa fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88804d8b5500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88804d8b5580: fb fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc ================================================================== Oops: general protection fault, probably for non-canonical address 0xdffffc0000000005: 0000 [#1] SMP KASAN NOPTI KASAN: null-ptr-deref in range [0x0000000000000028-0x000000000000002f] CPU: 1 UID: 0 PID: 4625 Comm: syz-executor.6 Tainted: G B 6.18.0-rc7-next-20251127 #1 PREEMPT(voluntary) Tainted: [B]=BAD_PAGE Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014 RIP: 0010:__fput+0x1cc/0xb50 Code: 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 f6 08 00 00 48 b8 00 00 00 00 00 fc ff df 4d 8b 7e 68 49 8d 7f 28 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 c9 08 00 00 48 ba 00 00 00 00 00 fc ff df 49 8b RSP: 0018:ffff888017367aa0 EFLAGS: 00010216 RAX: dffffc0000000000 RBX: ffff888018a5a8c0 RCX: ffffffff813a4cef RDX: 0000000000000005 RSI: ffffffff81b3432e RDI: 0000000000000028 RBP: ffff888013b05340 R08: 0000000000000001 R09: fffffbfff0f5e698 R10: 0000000000000000 R11: 0000000000000001 R12: ffff888013b05380 R13: 0000000000000008 R14: ffff88804d8b5490 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880e547a000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2d722000 CR3: 000000000e3ed000 CR4: 0000000000350ef0 Call Trace: task_work_run+0x172/0x280 do_exit+0x856/0x2950 do_group_exit+0xd3/0x2a0 get_signal+0x24aa/0x25d0 arch_do_signal_or_restart+0x80/0x7a0 exit_to_user_mode_loop+0x92/0x4d0 do_syscall_64+0x3c3/0x420 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fdb2969db19 Code: Unable to access opcode bytes at 0x7fdb2969daef. RSP: 002b:00007fdb26c13218 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 00007fdb297b0f68 RCX: 00007fdb2969db19 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fdb297b0f68 RBP: 00007fdb297b0f60 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fdb297b0f6c R13: 00007ffc02f498af R14: 00007fdb26c13300 R15: 0000000000022000 Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:__fput+0x1cc/0xb50 Code: 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 f6 08 00 00 48 b8 00 00 00 00 00 fc ff df 4d 8b 7e 68 49 8d 7f 28 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 c9 08 00 00 48 ba 00 00 00 00 00 fc ff df 49 8b RSP: 0018:ffff888017367aa0 EFLAGS: 00010216 RAX: dffffc0000000000 RBX: ffff888018a5a8c0 RCX: ffffffff813a4cef RDX: 0000000000000005 RSI: ffffffff81b3432e RDI: 0000000000000028 RBP: ffff888013b05340 R08: 0000000000000001 R09: fffffbfff0f5e698 R10: 0000000000000000 R11: 0000000000000001 R12: ffff888013b05380 R13: 0000000000000008 R14: ffff88804d8b5490 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880e547a000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2d722000 CR3: 000000000e3ed000 CR4: 0000000000350ef0 Fixing recursive fault but reboot is needed! BUG: scheduling while atomic: syz-executor.6/4625/0x00000000 INFO: lockdep is turned off. Modules linked in: CPU: 1 UID: 0 PID: 4625 Comm: syz-executor.6 Tainted: G B D 6.18.0-rc7-next-20251127 #1 PREEMPT(voluntary) Tainted: [B]=BAD_PAGE, [D]=DIE Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014 Call Trace: dump_stack_lvl+0xfa/0x120 __schedule_bug+0xb9/0x100 __schedule+0x249f/0x46a0 do_task_dead+0xdc/0x110 make_task_dead+0x373/0x3b0 rewind_stack_and_make_dead+0x16/0x20 RIP: 0033:0x7fdb2969db19 Code: Unable to access opcode bytes at 0x7fdb2969daef. RSP: 002b:00007fdb26c13218 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 00007fdb297b0f68 RCX: 00007fdb2969db19 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fdb297b0f68 RBP: 00007fdb297b0f60 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fdb297b0f6c R13: 00007ffc02f498af R14: 00007fdb26c13300 R15: 0000000000022000 ext3: Bad value for 'errors' ext3: Bad value for 'errors' ---------------- Code disassembly (best guess): 0: 48 89 fa mov %rdi,%rdx 3: 48 c1 ea 03 shr $0x3,%rdx 7: 80 3c 02 00 cmpb $0x0,(%rdx,%rax,1) b: 0f 85 f6 08 00 00 jne 0x907 11: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax 18: fc ff df 1b: 4d 8b 7e 68 mov 0x68(%r14),%r15 1f: 49 8d 7f 28 lea 0x28(%r15),%rdi 23: 48 89 fa mov %rdi,%rdx 26: 48 c1 ea 03 shr $0x3,%rdx * 2a: 80 3c 02 00 cmpb $0x0,(%rdx,%rax,1) <-- trapping instruction 2e: 0f 85 c9 08 00 00 jne 0x8fd 34: 48 ba 00 00 00 00 00 movabs $0xdffffc0000000000,%rdx 3b: fc ff df 3e: 49 rex.WB 3f: 8b .byte 0x8b