R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000002 R13: 00007ffc74b1b09f R14: 00007fe55b952300 R15: 0000000000022000 ================================================================== BUG: KASAN: slab-use-after-free in flush_tlb_func+0x24d/0x560 Write of size 8 at addr ffff88803cda13c0 by task syz-executor.6/6630 CPU: 1 UID: 0 PID: 6630 Comm: syz-executor.6 Not tainted 6.16.0-rc4-next-20250630 #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+0x39/0x1b0 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:ffff88806cf08f78 EFLAGS: 00000202 RAX: 00000000000002b6 RBX: 00000000ffffffff RCX: 0000000000000008 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff813b5b6e RBP: ffff88801eb0faa8 R08: 0000000000000001 R09: 0000000000000001 R10: ffffffff86438657 R11: 0000000000000001 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000200 R15: 0000000000000000 __irq_exit_rcu+0xc4/0x100 irq_exit_rcu+0x9/0x20 sysvec_apic_timer_interrupt+0x70/0x80 asm_sysvec_apic_timer_interrupt+0x1a/0x20 RIP: 0010:dump_stack_lvl+0x115/0x120 Code: fc ff ff 4c 89 e2 31 f6 31 ff e8 e6 40 7b fc e8 e1 f7 a4 fc 48 89 ee 31 ff e8 d7 95 c4 fc e8 72 9a c4 fc e8 7d c4 cc fc fb 5b <5d> 41 5c e9 63 9a c4 fc 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 RSP: 0018:ffff88801eb0fb50 EFLAGS: 00000206 RAX: 00000000000002b1 RBX: ffffffff85e964a0 RCX: 0000000000000080 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff84aefc13 RBP: 0000000000000200 R08: 0000000000000001 R09: 0000000000000001 R10: ffffffff86438657 R11: 0000000000000001 R12: ffffffff8530f500 R13: ffffffff85e964b0 R14: 0000000000000000 R15: 0000000000000000 should_fail_ex+0x4d7/0x5e0 _copy_from_user+0x30/0xd0 kstrtouint_from_user+0xbd/0x180 proc_fail_nth_write+0x7c/0x250 vfs_write+0x2b7/0x10c0 ksys_write+0x121/0x240 do_syscall_64+0xbf/0x360 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fe55e38f5ff Code: 89 54 24 18 48 89 74 24 10 89 7c 24 08 e8 99 fd ff ff 48 8b 54 24 18 48 8b 74 24 10 41 89 c0 8b 7c 24 08 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 31 44 89 c7 48 89 44 24 08 e8 cc fd ff ff 48 RSP: 002b:00007fe55b952170 EFLAGS: 00000293 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fe55e38f5ff RDX: 0000000000000001 RSI: 00007fe55b9521e0 RDI: 0000000000000003 RBP: 00007fe55b9521d0 R08: 0000000000000000 R09: 00007fe55b9521d0 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000002 R13: 00007ffc74b1b09f R14: 00007fe55b952300 R15: 0000000000022000 Allocated by task 280: kasan_save_stack+0x24/0x50 kasan_save_track+0x14/0x30 __kasan_slab_alloc+0x59/0x70 kmem_cache_alloc_noprof+0x13c/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 6626: kasan_save_stack+0x24/0x50 kasan_save_track+0x14/0x30 kasan_save_free_info+0x3a/0x60 __kasan_slab_free+0x38/0x50 kmem_cache_free+0x2a1/0x460 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 ffff88803cda0a40 which belongs to the cache mm_struct of size 2456 The buggy address is located 2432 bytes inside of freed 2456-byte region [ffff88803cda0a40, ffff88803cda13d8) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x3cda0 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 memcg:ffff88800df13b01 anon flags: 0x100000000000040(head|node=0|zone=1) page_type: f5(slab) raw: 0100000000000040 ffff888008c4bc80 ffffea0000b13c00 dead000000000003 raw: 0000000000000000 00000000000c000c 00000000f5000000 ffff88800df13b01 head: 0100000000000040 ffff888008c4bc80 ffffea0000b13c00 dead000000000003 head: 0000000000000000 00000000000c000c 00000000f5000000 ffff88800df13b01 head: 0100000000000003 ffffea0000f36801 00000000ffffffff 00000000ffffffff head: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000008 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88803cda1280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88803cda1300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88803cda1380: fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc fc ^ ffff88803cda1400: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88803cda1480: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ================================================================== EXT4-fs (loop1): mounted filesystem 00000000-0000-0000-0000-000000000000 r/w without journal. Quota mode: writeback. ext4 filesystem being mounted at /syzkaller-testdir303771649/syzkaller.3dnMoM/89/file0 supports timestamps until 2038-01-19 (0x7fffffff) EXT4-fs (loop1): unmounting filesystem 00000000-0000-0000-0000-000000000000. loop7: detected capacity change from 0 to 264192 loop7: detected capacity change from 0 to 264192 sr 1:0:0:0: [sr0] tag#0 FAILED Result: hostbyte=DID_OK driverbyte=DRIVER_OK cmd_age=0s sr 1:0:0:0: [sr0] tag#0 Sense Key : Not Ready [current] sr 1:0:0:0: [sr0] tag#0 Add. Sense: Medium not present sr 1:0:0:0: [sr0] tag#0 CDB: Read(10) 28 00 00 00 00 00 00 00 08 00 blk_print_req_error: 24 callbacks suppressed I/O error, dev sr0, sector 0 op 0x0:(READ) flags 0x80700 phys_seg 4 prio class 0 sr 1:0:0:0: [sr0] tag#0 unaligned transfer I/O error, dev sr0, sector 0 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 0 buffer_io_error: 30 callbacks suppressed Buffer I/O error on dev sr0, logical block 0, async page read sr 1:0:0:0: [sr0] tag#0 unaligned transfer I/O error, dev sr0, sector 1 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 0 Buffer I/O error on dev sr0, logical block 1, async page read sr 1:0:0:0: [sr0] tag#0 unaligned transfer I/O error, dev sr0, sector 2 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 0 Buffer I/O error on dev sr0, logical block 2, async page read sr 1:0:0:0: [sr0] tag#0 unaligned transfer I/O error, dev sr0, sector 3 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 0 Buffer I/O error on dev sr0, logical block 3, async page read sr 1:0:0:0: [sr0] tag#0 unaligned transfer I/O error, dev sr0, sector 4 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 0 Buffer I/O error on dev sr0, logical block 4, async page read sr 1:0:0:0: [sr0] tag#0 unaligned transfer I/O error, dev sr0, sector 5 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 0 Buffer I/O error on dev sr0, logical block 5, async page read sr 1:0:0:0: [sr0] tag#0 unaligned transfer I/O error, dev sr0, sector 6 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 0 Buffer I/O error on dev sr0, logical block 6, async page read sr 1:0:0:0: [sr0] tag#0 unaligned transfer I/O error, dev sr0, sector 7 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 0 Buffer I/O error on dev sr0, logical block 7, async page read ---------------- 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