R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
R13: 00007ffc604335ef R14: 00007f42b27f6300 R15: 0000000000022000
==================================================================
BUG: KASAN: slab-use-after-free in flush_tlb_func+0x24d/0x560
Write of size 8 at addr ffff888037025140 by task syz-fuzzer/255
CPU: 0 UID: 0 PID: 255 Comm: syz-fuzzer Not tainted 6.16.0-rc4-next-20250702 #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+0xa1/0xc0
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 b4 47 06 00 00 e8 42 6b 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: 0000:ffff88801ab9fec0 EFLAGS: 00000216
RAX: 0000000000089430 RBX: 00000000ffffffff RCX: ffffffff817bc5c6
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff813b5b6e
RBP: ffff88801ab9ff58 R08: 0000000000000001 R09: 0000000000000001
R10: ffffffff86439057 R11: 0000000000000001 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000002 R15: 0000000000000000
__irq_exit_rcu+0xc4/0x100
irq_exit_rcu+0x9/0x20
sysvec_apic_timer_interrupt+0x39/0x80
asm_sysvec_apic_timer_interrupt+0x1a/0x20
RIP: 0033:0x414873
Code: 89 cb 89 f1 48 d3 ea 48 21 fa 48 89 44 24 50 48 89 5c 24 58 48 89 54 24 60 48 8b 6c 24 28 48 83 c4 30 c3 48 29 d8 48 8b 51 68 <48> 39 d0 72 44 0f b6 71 65 40 80 fe 40 48 19 ff 44 0f b6 41 66 41
RSP: 002b:000000c000041e70 EFLAGS: 00000202
RAX: 0000000000001080 RBX: 000000c000082000 RCX: 00007f3de6440a20
RDX: 0000000000000180 RSI: 0000000000000002 RDI: fffffffffffc8d00
RBP: 000000c000041e98 R08: 00007f3de67d2fff R09: 000000c0000ba380
R10: 000000c000021e98 R11: 0000000000000050 R12: 000000c000083080
R13: 0000000001240aa0 R14: 0000000000000000 R15: 0000000000000000
Allocated by task 289:
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 8348:
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 ffff8880370247c0
which belongs to the cache mm_struct of size 2456
The buggy address is located 2432 bytes inside of
freed 2456-byte region [ffff8880370247c0, ffff888037025158)
The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x37020
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
memcg:ffff88800ba66701
flags: 0x100000000000040(head|node=0|zone=1)
page_type: f5(slab)
raw: 0100000000000040 ffff888008c4bc80 dead000000000100 dead000000000122
raw: 0000000000000000 00000000800c000c 00000000f5000000 ffff88800ba66701
head: 0100000000000040 ffff888008c4bc80 dead000000000100 dead000000000122
head: 0000000000000000 00000000800c000c 00000000f5000000 ffff88800ba66701
head: 0100000000000003 ffffea0000dc0801 00000000ffffffff 00000000ffffffff
head: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000008
page dumped because: kasan: bad access detected
Memory state around the buggy address:
ffff888037025000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff888037025080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888037025100: fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc fc
^
ffff888037025180: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff888037025200: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
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
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
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
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
sr 1:0:0:0: [sr0] tag#0 unaligned transfer
sr 1:0:0:0: [sr0] tag#0 unaligned transfer
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 02 00
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 02 00
loop3: detected capacity change from 0 to 512
EXT4-fs: Ignoring removed i_version option
FAULT_INJECTION: forcing a failure.
name fail_usercopy, interval 1, probability 0, space 0, times 0
CPU: 1 UID: 0 PID: 8374 Comm: syz-executor.4 Tainted: G B 6.16.0-rc4-next-20250702 #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
_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: 0033:0x7f42b523369c
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:00007f42b27f6170 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: ffffffffffffffff RCX: 00007f42b523369c
RDX: 000000000000000f RSI: 00007f42b27f61e0 RDI: 0000000000000003
RBP: 00007f42b27f61d0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
R13: 00007ffc604335ef R14: 00007f42b27f6300 R15: 0000000000022000
EXT4-fs (loop3): mounted filesystem 00000000-0000-0000-0000-000000000000 r/w without journal. Quota mode: none.
FAULT_INJECTION: forcing a failure.
name failslab, interval 1, probability 0, space 0, times 0
CPU: 0 UID: 0 PID: 8385 Comm: syz-executor.7 Tainted: G B 6.16.0-rc4-next-20250702 #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
should_failslab+0xc2/0x120
kmem_cache_alloc_node_noprof+0x71/0x470
__alloc_skb+0x2ab/0x370
alloc_skb_with_frags+0x8f/0x7c0
sock_alloc_send_pskb+0x7e5/0x960
__ip_append_data+0x155d/0x4110
ip_append_data+0x115/0x1a0
icmp_push_reply+0xa8/0x3f0
__icmp_send+0xc6f/0x1990
__udp4_lib_rcv+0x9da/0x2c20
ip_protocol_deliver_rcu+0x2f2/0x480
ip_local_deliver_finish+0x2f0/0x500
ip_local_deliver+0x1a3/0x200
ip_rcv+0x1c3/0x4b0
__netif_receive_skb_one_core+0x199/0x1e0
__netif_receive_skb+0x1d/0x170
netif_receive_skb+0x122/0x720
tun_rx_batched.isra.0+0x45c/0x710
tun_get_user+0x1c9b/0x3960
tun_chr_write_iter+0xd9/0x1e0
vfs_write+0xbe9/0x10c0
ksys_write+0x121/0x240
do_syscall_64+0xbf/0x360
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f5d112bb5ff
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:00007f5d0e87e150 EFLAGS: 00000293 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f5d1141bf60 RCX: 00007f5d112bb5ff
RDX: 000000000000002a RSI: 0000000020000200 RDI: 00000000000000f0
RBP: 00007f5d0e87e1d0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000001
R13: 00007ffd5fa20c8f R14: 00007f5d0e87e300 R15: 0000000000022000
EXT4-fs (loop3): unmounting filesystem 00000000-0000-0000-0000-000000000000.
----------------
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 b4 47 movw $0x0,%gs:0x647b4cf(%rip) # 0x647b4ee
1c: 06 00 00
1f: e8 42 6b 40 00 callq 0x406b66
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