R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000002 R13: 00007ffeb3ccfc3f R14: 00007fb8b4cde300 R15: 0000000000022000 ================================================================== BUG: KASAN: slab-use-after-free in flush_tlb_func+0x24d/0x560 Write of size 8 at addr ffff88801a0365c0 by task syz-executor.4/10964 CPU: 0 UID: 0 PID: 10964 Comm: syz-executor.4 Not tainted 6.16.0-rc4-next-20250701 #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/0x670 kasan_report+0xca/0x100 kasan_check_range+0x37/0x1a0 flush_tlb_func+0x24d/0x560 __flush_smp_call_function_queue+0x20d/0x740 __sysvec_call_function_single+0x6d/0x360 sysvec_call_function_single+0x5f/0xc0 asm_sysvec_call_function_single+0x1a/0x20 RIP: 0010:handle_softirqs+0x174/0x770 Code: c8 83 83 3c 0a 00 00 01 c7 44 24 20 0a 00 00 00 48 89 44 24 18 65 66 c7 05 cf 84 47 06 00 00 e8 22 65 40 00 fb bb ff ff ff ff <48> c7 c5 c0 c0 a0 85 41 0f bc de 83 c3 01 0f 85 9b 00 00 00 e9 8d RSP: 0018:ffff88806ce08f78 EFLAGS: 00000202 RAX: 0000000000000252 RBX: 00000000ffffffff RCX: 0000000000000004 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff813b5b6e RBP: ffff8880419af6b8 R08: 0000000000000001 R09: 0000000000000001 R10: ffffffff86438657 R11: 0000000000155cc0 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000200 R15: 0000000000000000 __irq_exit_rcu+0xc4/0x100 irq_exit_rcu+0x9/0x20 sysvec_call_function_single+0xa6/0xc0 asm_sysvec_call_function_single+0x1a/0x20 RIP: 0010:dump_stack_lvl+0x115/0x120 Code: fc ff ff 4c 89 e2 31 f6 31 ff e8 e6 50 7b fc e8 d1 07 a5 fc 48 89 ee 31 ff e8 d7 a5 c4 fc e8 72 aa c4 fc e8 7d d4 cc fc fb 5b <5d> 41 5c e9 63 aa c4 fc 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 RSP: 0018:ffff8880419af760 EFLAGS: 00000202 RAX: 000000000000024f RBX: ffffffff85d01f20 RCX: 0000000000000040 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff84aeec13 RBP: 0000000000000200 R08: 0000000000000001 R09: 0000000000000001 R10: ffffffff86438657 R11: 0000000000000001 R12: ffffffff8530f500 R13: ffffffff85d01f30 R14: 0000000000000000 R15: 0000000000000000 should_fail_ex+0x4d7/0x5e0 should_failslab+0xc2/0x120 kmem_cache_alloc_noprof+0x5f/0x470 vm_area_alloc+0x20/0x170 __mmap_region+0xc46/0x2670 mmap_region+0x314/0x3e0 do_mmap+0xa36/0x11d0 do_shmat+0xfac/0x1310 __x64_sys_shmat+0xcf/0x160 do_syscall_64+0xbf/0x360 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fb8b7768b19 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:00007fb8b4cde188 EFLAGS: 00000246 ORIG_RAX: 000000000000001e RAX: ffffffffffffffda RBX: 00007fb8b787bf60 RCX: 00007fb8b7768b19 RDX: 0000000000006000 RSI: 0000000020ffc000 RDI: 00000000000000a7 RBP: 00007fb8b4cde1d0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000002 R13: 00007ffeb3ccfc3f R14: 00007fb8b4cde300 R15: 0000000000022000 loop6: detected capacity change from 0 to 274 Allocated by task 277: kasan_save_stack+0x24/0x50 kasan_save_track+0x14/0x30 __kasan_slab_alloc+0x59/0x70 kmem_cache_alloc_noprof+0x13e/0x470 copy_process+0x6f3a/0x73e0 kernel_clone+0xea/0x820 __do_sys_clone+0xce/0x120 do_syscall_64+0xbf/0x360 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 10960: kasan_save_stack+0x24/0x50 kasan_save_track+0x14/0x30 kasan_save_free_info+0x3c/0x90 __kasan_slab_free+0x3c/0x60 kmem_cache_free+0x2a5/0x460 mmput+0x305/0x390 do_exit+0x79d/0x2970 do_group_exit+0xd3/0x2a0 get_signal+0x2315/0x2340 arch_do_signal_or_restart+0x80/0x790 exit_to_user_mode_loop+0x8b/0x100 do_syscall_64+0x2f7/0x360 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff88801a035c40 which belongs to the cache mm_struct of size 2456 The buggy address is located 2432 bytes inside of freed 2456-byte region [ffff88801a035c40, ffff88801a0365d8) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1a030 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 memcg:ffff88800b6f1301 anon flags: 0x100000000000040(head|node=0|zone=1) page_type: f5(slab) raw: 0100000000000040 ffff888008c4bc80 ffffea0000298c00 dead000000000003 raw: 0000000000000000 00000000800c000c 00000000f5000000 ffff88800b6f1301 head: 0100000000000040 ffff888008c4bc80 ffffea0000298c00 dead000000000003 head: 0000000000000000 00000000800c000c 00000000f5000000 ffff88800b6f1301 head: 0100000000000003 ffffea0000680c01 00000000ffffffff 00000000ffffffff head: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000008 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88801a036480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88801a036500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88801a036580: fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc fc ^ ffff88801a036600: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88801a036680: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ================================================================== loop5: detected capacity change from 0 to 10 FAULT_INJECTION: forcing a failure. name fail_page_alloc, interval 1, probability 0, space 0, times 0 CPU: 1 UID: 0 PID: 10994 Comm: syz-executor.7 Tainted: G B 6.16.0-rc4-next-20250701 #1 PREEMPT(voluntary) Tainted: [B]=BAD_PAGE 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 FAT-fs (loop5): bogus number of reserved sectors should_fail_alloc_page+0xe0/0x110 prepare_alloc_pages+0x1af/0x500 __alloc_frozen_pages_noprof+0x17f/0x1f10 alloc_pages_mpol+0xed/0x340 vma_alloc_folio_noprof+0xe9/0x440 __handle_mm_fault+0x142c/0x30f0 handle_mm_fault+0x2c3/0x900 __get_user_pages+0x58a/0x2f10 faultin_page_range+0x2f3/0x9d0 madvise_do_behavior+0x8d8/0xe20 do_madvise+0x16b/0x240 __x64_sys_madvise+0xa9/0x110 do_syscall_64+0xbf/0x360 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f8fdf467b19 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:00007f8fdc9dd188 EFLAGS: 00000246 ORIG_RAX: 000000000000001c RAX: ffffffffffffffda RBX: 00007f8fdf57af60 RCX: 00007f8fdf467b19 RDX: 0000000000000017 RSI: 0000000000002000 RDI: 0000000020ffe000 RBP: 00007f8fdc9dd1d0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000002 R13: 00007ffe58ee06ff R14: 00007f8fdc9dd300 R15: 0000000000022000 loop6: detected capacity change from 0 to 274 FAT-fs (loop5): Can't find a valid FAT filesystem FAT-fs (loop6): error, fat_get_cluster: invalid cluster chain (i_pos 0) FAT-fs (loop6): Filesystem has been set read-only ---------------- Code disassembly (best guess): 0: c8 83 83 3c enterq $0x8383,$0x3c 4: 0a 00 or (%rax),%al 6: 00 01 add %al,(%rcx) 8: c7 44 24 20 0a 00 00 movl $0xa,0x20(%rsp) f: 00 10: 48 89 44 24 18 mov %rax,0x18(%rsp) 15: 65 66 c7 05 cf 84 47 movw $0x0,%gs:0x64784cf(%rip) # 0x64784ee 1c: 06 00 00 1f: e8 22 65 40 00 callq 0x406546 24: fb sti 25: bb ff ff ff ff mov $0xffffffff,%ebx * 2a: 48 c7 c5 c0 c0 a0 85 mov $0xffffffff85a0c0c0,%rbp <-- trapping instruction 31: 41 0f bc de bsf %r14d,%ebx 35: 83 c3 01 add $0x1,%ebx 38: 0f 85 9b 00 00 00 jne 0xd9 3e: e9 .byte 0xe9 3f: 8d .byte 0x8d