R10: 0000000000000011 R11: 0000000000000246 R12: 0000000000000002 R13: 00007ffd549d0b7f R14: 00007f7db925c300 R15: 0000000000022000 ================================================================== BUG: KASAN: slab-use-after-free in flush_tlb_func+0x24d/0x560 Write of size 8 at addr ffff88803db593c0 by task syz-executor.3/16017 CPU: 0 UID: 0 PID: 16017 Comm: syz-executor.3 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: 00000206 RAX: 0000000000000184 RBX: 00000000ffffffff RCX: 0000000000000004 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff813b5b6e RBP: ffff88803d20fb18 R08: 0000000000000001 R09: 0000000000000001 R10: ffffffff86438657 R11: 0000000000000001 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000382 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 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:ffff88803d20fbc8 EFLAGS: 00000206 RAX: 0000000000000181 RBX: ffffffff85e96520 RCX: 0000000000000040 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff84aeec13 RBP: 0000000000000200 R08: 0000000000000001 R09: 0000000000000001 R10: ffffffff86438657 R11: fffffffffffcd570 R12: ffffffff8530f500 R13: ffffffff85e96530 R14: 0000000000000000 R15: 0000000000000000 should_fail_ex+0x4d7/0x5e0 _copy_to_user+0x32/0xd0 simple_read_from_buffer+0xe0/0x180 proc_fail_nth_read+0x189/0x270 vfs_read+0x1eb/0xbe0 ksys_read+0x121/0x240 do_syscall_64+0xbf/0x360 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f7dbbc9969c Code: ec 28 48 89 54 24 18 48 89 74 24 10 89 7c 24 08 e8 f9 fc ff ff 48 8b 54 24 18 48 8b 74 24 10 41 89 c0 8b 7c 24 08 31 c0 0f 05 <48> 3d 00 f0 ff ff 77 34 44 89 c7 48 89 44 24 08 e8 2f fd ff ff 48 RSP: 002b:00007f7db925c170 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: ffffffffffffffff RCX: 00007f7dbbc9969c RDX: 000000000000000f RSI: 00007f7db925c1e0 RDI: 0000000000000004 RBP: 00007f7db925c1d0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000011 R11: 0000000000000246 R12: 0000000000000002 R13: 00007ffd549d0b7f R14: 00007f7db925c300 R15: 0000000000022000 loop0: detected capacity change from 0 to 512 Allocated by task 280: 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 16009: 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 __x64_sys_exit_group+0x3e/0x50 x64_sys_call+0xf76/0x18a0 do_syscall_64+0xbf/0x360 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff88803db58a40 which belongs to the cache mm_struct of size 2456 The buggy address is located 2432 bytes inside of freed 2456-byte region [ffff88803db58a40, ffff88803db593d8) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x3db58 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 memcg:ffff88801dd8f281 flags: 0x100000000000040(head|node=0|zone=1) page_type: f5(slab) raw: 0100000000000040 ffff888008c4bc80 ffffea000060de00 dead000000000002 raw: 0000000000000000 00000000000c000c 00000000f5000000 ffff88801dd8f281 head: 0100000000000040 ffff888008c4bc80 ffffea000060de00 dead000000000002 head: 0000000000000000 00000000000c000c 00000000f5000000 ffff88801dd8f281 head: 0100000000000003 ffffea0000f6d601 00000000ffffffff 00000000ffffffff head: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000008 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88803db59280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88803db59300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88803db59380: fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc fc ^ ffff88803db59400: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88803db59480: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== loop7: detected capacity change from 0 to 512 EXT4-fs (loop0): mounted filesystem 00000000-0000-0000-0000-000000000000 r/w without journal. Quota mode: writeback. EXT4-fs error (device loop7): ext4_ext_check_inode:523: inode #2: comm syz-executor.7: pblk 0 bad header/extent: invalid extent entries - magic f30a, entries 1, max 4(4), depth 0(0) ext4 filesystem being mounted at /syzkaller-testdir774868573/syzkaller.OmCPNE/322/file0 supports timestamps until 2038-01-19 (0x7fffffff) EXT4-fs (loop7): get root inode failed EXT4-fs (loop7): mount failed loop5: detected capacity change from 0 to 512 EXT4-fs error (device loop5): ext4_ext_check_inode:523: inode #2: comm syz-executor.5: pblk 0 bad header/extent: invalid extent entries - magic f30a, entries 1, max 4(4), depth 0(0) EXT4-fs (loop5): get root inode failed EXT4-fs (loop5): mount failed EXT4-fs (loop0): unmounting filesystem 00000000-0000-0000-0000-000000000000. loop2: detected capacity change from 0 to 512 EXT4-fs (loop2): mounted filesystem 00000000-0000-0000-0000-000000000000 r/w without journal. Quota mode: writeback. ext4 filesystem being mounted at /syzkaller-testdir004202176/syzkaller.H3I8sV/286/file0 supports timestamps until 2038-01-19 (0x7fffffff) Quota error (device loop2): do_check_range: Getting block 60418 out of range 1-5 Quota error (device loop2): qtree_read_dquot: Can't read quota structure for id 0 EXT4-fs error (device loop2): ext4_acquire_dquot:6931: comm syz-executor.2: Failed to acquire dquot type 1 loop0: detected capacity change from 0 to 512 loop1: detected capacity change from 0 to 512 EXT4-fs (loop0): mounted filesystem 00000000-0000-0000-0000-000000000000 r/w without journal. Quota mode: writeback. ext4 filesystem being mounted at /syzkaller-testdir774868573/syzkaller.OmCPNE/323/file0 supports timestamps until 2038-01-19 (0x7fffffff) loop5: detected capacity change from 0 to 512 EXT4-fs (loop0): unmounting filesystem 00000000-0000-0000-0000-000000000000. EXT4-fs (loop1): mounted filesystem 00000000-0000-0000-0000-000000000000 r/w without journal. Quota mode: writeback. ext4 filesystem being mounted at /syzkaller-testdir384785317/syzkaller.aDlixR/308/file0 supports timestamps until 2038-01-19 (0x7fffffff) EXT4-fs (loop2): unmounting filesystem 00000000-0000-0000-0000-000000000000. EXT4-fs error (device loop5): ext4_ext_check_inode:523: inode #2: comm syz-executor.5: pblk 0 bad header/extent: invalid extent entries - magic f30a, entries 1, max 4(4), depth 0(0) EXT4-fs (loop1): unmounting filesystem 00000000-0000-0000-0000-000000000000. loop7: detected capacity change from 0 to 512 EXT4-fs (loop5): get root inode failed EXT4-fs (loop5): mount failed EXT4-fs error (device loop7): __ext4_fill_super:5500: inode #2: comm syz-executor.7: iget: special inode unallocated EXT4-fs (loop7): get root inode failed EXT4-fs (loop7): mount failed ---------------- 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