EXT4-fs error (device loop2): ext4_ext_check_inode:523: inode #2: comm syz-executor.2: pblk 0 bad header/extent: invalid extent entries - magic f30a, entries 1, max 4(4), depth 8898(8898)
==================================================================
BUG: KASAN: slab-use-after-free in flush_tlb_func+0x24d/0x560
Write of size 8 at addr ffff888016f313c0 by task syz-executor.5/5125
CPU: 0 UID: 0 PID: 5125 Comm: syz-executor.5 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
EXT4-fs (loop2): get root inode failed
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:ffff88806ce08f78 EFLAGS: 00000216
RAX: 0000000000000490 RBX: 00000000ffffffff RCX: ffffffff817bbfa6
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff813b5b6e
RBP: ffff88801d7df9d8 R08: 0000000000000001 R09: 0000000000000001
R10: ffffffff86438657 R11: 0000000000000001 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000002 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:_raw_spin_unlock_irqrestore+0x34/0x50
Code: c7 18 53 48 89 f3 48 8b 74 24 10 e8 c6 28 97 fc 48 89 ef e8 fe 73 97 fc 80 e7 02 74 06 e8 54 3b c1 fc fb 65 ff 0d ec 5a c8 02 <74> 07 5b 5d e9 f3 1e 00 00 0f 1f 44 00 00 5b 5d e9 e7 1e 00 00 0f
RSP: 0018:ffff88801d7dfa80 EFLAGS: 00000286
RAX: 000000000000048d RBX: 0000000000000286 RCX: ffffffff817bbfa6
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff84ba853c
RBP: ffffffff85d0b400 R08: 0000000000000001 R09: 0000000000000001
R10: ffffffff86438657 R11: 0000000000000001 R12: ffff888016889580
R13: 0000000000000230 R14: 0000000000000001 R15: 0000000000000286
__create_object+0x59/0x80
kmem_cache_alloc_noprof+0x397/0x470
taskstats_exit+0x672/0xba0
do_exit+0x5d1/0x2970
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
RIP: 0033:0x7f75abbdcb19
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:00007ffd80610d98 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffdfc RBX: 0000000000000032 RCX: 00007f75abbdcb19
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f75abceff6c
RBP: 00007f75abceff6c R08: 00007f75abccc000 R09: 0000000000000000
R10: 00007ffd80610e70 R11: 0000000000000246 R12: 00000000000521ef
R13: 00000000000003e8 R14: 00007f75abceff60 R15: 00000000000521ee
EXT4-fs (loop2): mount failed
Allocated by task 291:
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 5117:
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 ffff888016f30a40
which belongs to the cache mm_struct of size 2456
The buggy address is located 2432 bytes inside of
freed 2456-byte region [ffff888016f30a40, ffff888016f313d8)
The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x16f30
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
memcg:ffff88800e43e381
anon flags: 0x100000000000040(head|node=0|zone=1)
page_type: f5(slab)
raw: 0100000000000040 ffff888008c4bc80 0000000000000000 dead000000000001
raw: 0000000000000000 00000000800c000c 00000000f5000000 ffff88800e43e381
head: 0100000000000040 ffff888008c4bc80 0000000000000000 dead000000000001
head: 0000000000000000 00000000800c000c 00000000f5000000 ffff88800e43e381
head: 0100000000000003 ffffea00005bcc01 00000000ffffffff 00000000ffffffff
head: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000008
page dumped because: kasan: bad access detected
Memory state around the buggy address:
ffff888016f31280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff888016f31300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888016f31380: fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc fc
^
ffff888016f31400: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff888016f31480: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
FAULT_INJECTION: forcing a failure.
name failslab, interval 1, probability 0, space 0, times 0
CPU: 0 UID: 0 PID: 5147 Comm: syz-executor.4 Tainted: G B 6.16.0-rc4-next-20250630 #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_noprof+0x5f/0x470
__es_insert_extent+0xed2/0x1370
ext4_es_insert_extent+0x4d0/0x1100
ext4_ext_map_blocks+0x1797/0x5f30
ext4_map_query_blocks+0x117/0x890
ext4_map_blocks+0x4c3/0x15a0
ext4_append+0x1b6/0x530
ext4_init_new_dir+0x21e/0x460
ext4_mkdir+0x3c5/0xb30
vfs_mkdir+0x59a/0x8d0
do_mkdirat+0x19f/0x3d0
__x64_sys_mkdir+0xf3/0x140
do_syscall_64+0xbf/0x360
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f12240f4c27
Code: 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 53 00 00 00 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:00007f122166afa8 EFLAGS: 00000246 ORIG_RAX: 0000000000000053
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f12240f4c27
RDX: 0000000000000000 RSI: 00000000000001ff RDI: 0000000020000100
RBP: 00007f122166b040 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000020000000
R13: 0000000020000100 R14: 00007f122166b000 R15: 0000000020000040
loop2: detected capacity change from 0 to 2048
loop0: detected capacity change from 0 to 2048
EXT4-fs error (device loop0): ext4_ext_check_inode:523: inode #2: comm syz-executor.0: pblk 0 bad header/extent: invalid extent entries - magic f30a, entries 1, max 4(4), depth 8898(8898)
EXT4-fs: dax option not supported
EXT4-fs error (device loop2): ext4_ext_check_inode:523: inode #2: comm syz-executor.2: pblk 0 bad header/extent: invalid extent entries - magic f30a, entries 1, max 4(4), depth 8898(8898)
EXT4-fs (loop0): get root inode failed
EXT4-fs (loop0): mount failed
EXT4-fs (loop2): get root inode failed
EXT4-fs (loop2): mount failed
SELinux: Context system_ is not valid (left unmapped).
EXT4-fs: dax option not supported
----------------
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