incfs: ino conflict with backing FS 2
==================================================================
BUG: KASAN: slab-out-of-bounds in ext4_xattr_set_entry+0x1a71/0x21d0 fs/ext4/xattr.c:1703
Read of size 25977 at addr ffff88813195d400 by task syz.3.1693/5848
CPU: 1 PID: 5848 Comm: syz.3.1693 Tainted: G W syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
__dump_stack+0x21/0x24 lib/dump_stack.c:88
dump_stack_lvl+0x110/0x170 lib/dump_stack.c:106
print_address_description+0x71/0x200 mm/kasan/report.c:316
print_report+0x4a/0x60 mm/kasan/report.c:420
kasan_report+0x122/0x150 mm/kasan/report.c:524
check_region_inline mm/kasan/generic.c:-1 [inline]
kasan_check_range+0x249/0x2a0 mm/kasan/generic.c:189
memmove+0x2d/0x70 mm/kasan/shadow.c:54
ext4_xattr_set_entry+0x1a71/0x21d0 fs/ext4/xattr.c:1703
ext4_xattr_block_set+0xad3/0x3260 fs/ext4/xattr.c:1993
ext4_xattr_set_handle+0xbc4/0x12c0 fs/ext4/xattr.c:2418
ext4_xattr_set+0x242/0x320 fs/ext4/xattr.c:2520
ext4_xattr_trusted_set+0x3c/0x50 fs/ext4/xattr_trusted.c:38
__vfs_setxattr+0x3f2/0x440 fs/xattr.c:182
__vfs_setxattr_noperm+0x12a/0x5e0 fs/xattr.c:216
__vfs_setxattr_locked+0x212/0x230 fs/xattr.c:277
vfs_setxattr+0x167/0x2e0 fs/xattr.c:309
incfs_setxattr fs/incfs/vfs.c:1782 [inline]
incfs_handler_setxattr+0x102/0x340 fs/incfs/vfs.c:200
__vfs_setxattr+0x3f2/0x440 fs/xattr.c:182
__vfs_setxattr_noperm+0x12a/0x5e0 fs/xattr.c:216
__vfs_setxattr_locked+0x212/0x230 fs/xattr.c:277
vfs_setxattr+0x167/0x2e0 fs/xattr.c:309
do_setxattr fs/xattr.c:594 [inline]
setxattr+0x346/0x360 fs/xattr.c:617
path_setxattr+0x147/0x290 fs/xattr.c:636
__do_sys_lsetxattr fs/xattr.c:659 [inline]
__se_sys_lsetxattr fs/xattr.c:655 [inline]
__x64_sys_lsetxattr+0xc2/0xe0 fs/xattr.c:655
x64_sys_call+0x8b7/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:190
do_syscall_x64 arch/x86/entry/common.c:46 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fcb8bb9aeb9
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fcb8cab4028 EFLAGS: 00000246 ORIG_RAX: 00000000000000bd
RAX: ffffffffffffffda RBX: 00007fcb8be15fa0 RCX: 00007fcb8bb9aeb9
RDX: 0000200000000300 RSI: 00002000000000c0 RDI: 0000200000000100
RBP: 00007fcb8bc08c1f R08: 0000000000000000 R09: 0000000000000000
R10: 000000000000fe37 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fcb8be16038 R14: 00007fcb8be15fa0 R15: 00007ffe582e95f8
Allocated by task 5848:
kasan_save_stack mm/kasan/common.c:46 [inline]
kasan_set_track+0x4b/0x70 mm/kasan/common.c:53
kasan_save_alloc_info+0x25/0x30 mm/kasan/generic.c:505
____kasan_kmalloc mm/kasan/common.c:380 [inline]
__kasan_kmalloc+0x95/0xb0 mm/kasan/common.c:389
kasan_kmalloc include/linux/kasan.h:212 [inline]
__do_kmalloc_node mm/slab_common.c:938 [inline]
__kmalloc_node_track_caller+0xb1/0x1e0 mm/slab_common.c:958
kmemdup+0x2b/0x60 mm/util.c:134
kmemdup include/linux/fortify-string.h:585 [inline]
ext4_xattr_block_set+0x9d5/0x3260 fs/ext4/xattr.c:1941
ext4_xattr_set_handle+0xbc4/0x12c0 fs/ext4/xattr.c:2418
ext4_xattr_set+0x242/0x320 fs/ext4/xattr.c:2520
ext4_xattr_trusted_set+0x3c/0x50 fs/ext4/xattr_trusted.c:38
__vfs_setxattr+0x3f2/0x440 fs/xattr.c:182
__vfs_setxattr_noperm+0x12a/0x5e0 fs/xattr.c:216
__vfs_setxattr_locked+0x212/0x230 fs/xattr.c:277
vfs_setxattr+0x167/0x2e0 fs/xattr.c:309
incfs_setxattr fs/incfs/vfs.c:1782 [inline]
incfs_handler_setxattr+0x102/0x340 fs/incfs/vfs.c:200
__vfs_setxattr+0x3f2/0x440 fs/xattr.c:182
__vfs_setxattr_noperm+0x12a/0x5e0 fs/xattr.c:216
__vfs_setxattr_locked+0x212/0x230 fs/xattr.c:277
vfs_setxattr+0x167/0x2e0 fs/xattr.c:309
do_setxattr fs/xattr.c:594 [inline]
setxattr+0x346/0x360 fs/xattr.c:617
path_setxattr+0x147/0x290 fs/xattr.c:636
__do_sys_lsetxattr fs/xattr.c:659 [inline]
__se_sys_lsetxattr fs/xattr.c:655 [inline]
__x64_sys_lsetxattr+0xc2/0xe0 fs/xattr.c:655
x64_sys_call+0x8b7/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:190
do_syscall_x64 arch/x86/entry/common.c:46 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2
Last potentially related work creation:
kasan_save_stack+0x3a/0x60 mm/kasan/common.c:46
__kasan_record_aux_stack+0xb6/0xc0 mm/kasan/generic.c:486
kasan_record_aux_stack_noalloc+0xb/0x10 mm/kasan/generic.c:496
insert_work+0x51/0x300 kernel/workqueue.c:1368
__queue_work+0x9b1/0xd30 kernel/workqueue.c:1527
queue_work_on+0xde/0x150 kernel/workqueue.c:1555
queue_work include/linux/workqueue.h:510 [inline]
schedule_work include/linux/workqueue.h:571 [inline]
queue_release_one_tty drivers/tty/tty_io.c:1552 [inline]
kref_put include/linux/kref.h:65 [inline]
tty_kref_put drivers/tty/tty_io.c:1565 [inline]
release_tty+0x739/0x820 drivers/tty/tty_io.c:1601
tty_release_struct+0xbf/0xe0 drivers/tty/tty_io.c:1700
tty_release+0xbfd/0x1210 drivers/tty/tty_io.c:1860
__fput+0x1fc/0x8f0 fs/file_table.c:320
____fput+0x15/0x20 fs/file_table.c:348
task_work_run+0x1e1/0x250 kernel/task_work.c:203
exit_task_work include/linux/task_work.h:39 [inline]
do_exit+0xa35/0x2660 kernel/exit.c:886
do_group_exit+0x210/0x2d0 kernel/exit.c:1028
get_signal+0x13b5/0x1520 kernel/signal.c:2891
arch_do_signal_or_restart+0xd1/0x1140 arch/x86/kernel/signal.c:871
exit_to_user_mode_loop+0x7a/0xb0 kernel/entry/common.c:174
exit_to_user_mode_prepare+0x87/0xd0 kernel/entry/common.c:210
irqentry_exit_to_user_mode+0x9/0x10 kernel/entry/common.c:316
irqentry_exit+0x12/0x40 kernel/entry/common.c:419
exc_page_fault+0x5e/0xb0 arch/x86/mm/fault.c:1525
asm_exc_page_fault+0x27/0x30 arch/x86/include/asm/idtentry.h:608
The buggy address belongs to the object at ffff88813195d000
which belongs to the cache kmalloc-1k of size 1024
The buggy address is located 0 bytes to the right of
1024-byte region [ffff88813195d000, ffff88813195d400)
The buggy address belongs to the physical page:
page:ffffea0004c65600 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x131958
head:ffffea0004c65600 order:3 compound_mapcount:0 compound_pincount:0
flags: 0x4000000000010200(slab|head|zone=1)
raw: 4000000000010200 0000000000000000 dead000000000001 ffff888100043080
raw: 0000000000000000 0000000080100010 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd60c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_RETRY_MAYFAIL|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 287, tgid 287 (syz-executor), ts 24027652828, free_ts 0
set_page_owner include/linux/page_owner.h:33 [inline]
post_alloc_hook+0x1f5/0x210 mm/page_alloc.c:2643
prep_new_page+0x1c/0x110 mm/page_alloc.c:2650
get_page_from_freelist+0x2d12/0x2d80 mm/page_alloc.c:4554
__alloc_pages+0x1d9/0x480 mm/page_alloc.c:5868
alloc_slab_page+0x6e/0xf0 include/linux/gfp.h:-1
allocate_slab mm/slub.c:1967 [inline]
new_slab+0x98/0x3d0 mm/slub.c:2020
___slab_alloc+0x6bd/0xb20 mm/slub.c:3177
__slab_alloc+0x5e/0xa0 mm/slub.c:3263
slab_alloc_node mm/slub.c:3348 [inline]
__kmem_cache_alloc_node+0x203/0x2c0 mm/slub.c:3423
__do_kmalloc_node mm/slab_common.c:937 [inline]
__kmalloc_node+0xa1/0x1e0 mm/slab_common.c:945
kmalloc_node include/linux/slab.h:589 [inline]
kvmalloc_node+0x28a/0x460 mm/util.c:592
kvmalloc include/linux/slab.h:716 [inline]
kvzalloc include/linux/slab.h:724 [inline]
netif_alloc_netdev_queues net/core/dev.c:10031 [inline]
alloc_netdev_mqs+0x7b7/0xf90 net/core/dev.c:10767
rtnl_create_link+0x319/0xb10 net/core/rtnetlink.c:3295
rtnl_newlink_create net/core/rtnetlink.c:3412 [inline]
__rtnl_newlink net/core/rtnetlink.c:3642 [inline]
rtnl_newlink+0x1439/0x20b0 net/core/rtnetlink.c:3655
rtnetlink_rcv_msg+0xb3b/0xe00 net/core/rtnetlink.c:6150
netlink_rcv_skb+0x20f/0x460 net/netlink/af_netlink.c:2521
page_owner free stack trace missing
Memory state around the buggy address:
ffff88813195d300: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ffff88813195d380: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff88813195d400: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
^
ffff88813195d480: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff88813195d500: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================
general protection fault, probably for non-canonical address 0xdffffc0000000160: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000b00-0x0000000000000b07]
CPU: 0 PID: 5848 Comm: syz.3.1693 Tainted: G B W syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:rq_clock_task kernel/sched/sched.h:1539 [inline]
RIP: 0010:update_curr+0x70/0x600 kernel/sched/fair.c:898
Code: b3 30 01 00 00 4c 89 f0 48 c1 e8 03 42 80 3c 28 00 74 08 4c 89 f7 e8 cf ac 67 00 bb 00 0b 00 00 49 03 1e 48 89 d8 48 c1 e8 03 <42> 80 3c 28 00 74 08 48 89 df e8 b1 ac 67 00 4c 89 7d c8 4d 85 ff
RSP: 0018:ffffc90002a6ecb8 EFLAGS: 00010006
RAX: 0000000000000160 RBX: 0000000000000b00 RCX: dffffc0000000001
RDX: ffff888109a814c0 RSI: ffff88811f432900 RDI: ffff888132874400
RBP: ffffc90002a6ed10 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff5200054ddc0 R12: 1ffff1102650e888
R13: dffffc0000000000 R14: ffff888132874530 R15: 0000000000000000
FS: 00007fcb8cab46c0(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f0e82be1198 CR3: 000000010d356000 CR4: 00000000003506b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
put_prev_entity+0x4a/0x3b0 kernel/sched/fair.c:5106
pick_next_task_fair+0x5b1/0xa80 kernel/sched/fair.c:7968
__pick_next_task kernel/sched/core.c:6058 [inline]
pick_next_task kernel/sched/core.c:6567 [inline]
__schedule+0x452/0x1500 kernel/sched/core.c:6712
preempt_schedule_irq+0xaa/0x120 kernel/sched/core.c:7062
raw_irqentry_exit_cond_resched+0x29/0x30 kernel/entry/common.c:396
irqentry_exit+0x37/0x40 kernel/entry/common.c:439
sysvec_apic_timer_interrupt+0x64/0xc0 arch/x86/kernel/apic/apic.c:1118
asm_sysvec_apic_timer_interrupt+0x1b/0x20 arch/x86/include/asm/idtentry.h:691
RIP: 0010:memset_erms+0x9/0x10 arch/x86/lib/memset_64.S:64
Code: c1 e9 03 40 0f b6 f6 48 b8 01 01 01 01 01 01 01 01 48 0f af c6 f3 48 ab 89 d1 f3 aa 4c 89 c8 c3 90 49 89 f9 40 88 f0 48 89 d1 aa 4c 89 c8 c3 90 49 89 fa 40 0f b6 ce 48 b8 01 01 01 01 01 01
RSP: 0018:ffffc90002a6f110 EFLAGS: 00010202
RAX: 0000000000000000 RBX: 00000000042480f4 RCX: 00000000032611f4
RDX: 00000000042480f4 RSI: 0000000000000000 RDI: ffff888132944300
RBP: ffffc90002a6f130 R08: ffff888135ba54f3 R09: ffff88813195d400
R10: dffffc0000000000 R11: ffffed102632ba80 R12: 0000000000000000
R13: 00000000042480f4 R14: 0000000000000000 R15: ffff88813195d400
ext4_xattr_set_entry+0x1a7e/0x21d0 fs/ext4/xattr.c:1704
ext4_xattr_block_set+0xad3/0x3260 fs/ext4/xattr.c:1993
ext4_xattr_set_handle+0xbc4/0x12c0 fs/ext4/xattr.c:2418
ext4_xattr_set+0x242/0x320 fs/ext4/xattr.c:2520
ext4_xattr_trusted_set+0x3c/0x50 fs/ext4/xattr_trusted.c:38
__vfs_setxattr+0x3f2/0x440 fs/xattr.c:182
__vfs_setxattr_noperm+0x12a/0x5e0 fs/xattr.c:216
__vfs_setxattr_locked+0x212/0x230 fs/xattr.c:277
vfs_setxattr+0x167/0x2e0 fs/xattr.c:309
incfs_setxattr fs/incfs/vfs.c:1782 [inline]
incfs_handler_setxattr+0x102/0x340 fs/incfs/vfs.c:200
__vfs_setxattr+0x3f2/0x440 fs/xattr.c:182
__vfs_setxattr_noperm+0x12a/0x5e0 fs/xattr.c:216
__vfs_setxattr_locked+0x212/0x230 fs/xattr.c:277
vfs_setxattr+0x167/0x2e0 fs/xattr.c:309
do_setxattr fs/xattr.c:594 [inline]
setxattr+0x346/0x360 fs/xattr.c:617
path_setxattr+0x147/0x290 fs/xattr.c:636
__do_sys_lsetxattr fs/xattr.c:659 [inline]
__se_sys_lsetxattr fs/xattr.c:655 [inline]
__x64_sys_lsetxattr+0xc2/0xe0 fs/xattr.c:655
x64_sys_call+0x8b7/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:190
do_syscall_x64 arch/x86/entry/common.c:46 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fcb8bb9aeb9
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fcb8cab4028 EFLAGS: 00000246 ORIG_RAX: 00000000000000bd
RAX: ffffffffffffffda RBX: 00007fcb8be15fa0 RCX: 00007fcb8bb9aeb9
RDX: 0000200000000300 RSI: 00002000000000c0 RDI: 0000200000000100
RBP: 00007fcb8bc08c1f R08: 0000000000000000 R09: 0000000000000000
R10: 000000000000fe37 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fcb8be16038 R14: 00007fcb8be15fa0 R15: 00007ffe582e95f8
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:rq_clock_task kernel/sched/sched.h:1539 [inline]
RIP: 0010:update_curr+0x70/0x600 kernel/sched/fair.c:898
Code: b3 30 01 00 00 4c 89 f0 48 c1 e8 03 42 80 3c 28 00 74 08 4c 89 f7 e8 cf ac 67 00 bb 00 0b 00 00 49 03 1e 48 89 d8 48 c1 e8 03 <42> 80 3c 28 00 74 08 48 89 df e8 b1 ac 67 00 4c 89 7d c8 4d 85 ff
RSP: 0018:ffffc90002a6ecb8 EFLAGS: 00010006
RAX: 0000000000000160 RBX: 0000000000000b00 RCX: dffffc0000000001
RDX: ffff888109a814c0 RSI: ffff88811f432900 RDI: ffff888132874400
RBP: ffffc90002a6ed10 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff5200054ddc0 R12: 1ffff1102650e888
R13: dffffc0000000000 R14: ffff888132874530 R15: 0000000000000000
FS: 00007fcb8cab46c0(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f0e82be1198 CR3: 000000010d356000 CR4: 00000000003506b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
0: b3 30 mov $0x30,%bl
2: 01 00 add %eax,(%rax)
4: 00 4c 89 f0 add %cl,-0x10(%rcx,%rcx,4)
8: 48 c1 e8 03 shr $0x3,%rax
c: 42 80 3c 28 00 cmpb $0x0,(%rax,%r13,1)
11: 74 08 je 0x1b
13: 4c 89 f7 mov %r14,%rdi
16: e8 cf ac 67 00 call 0x67acea
1b: bb 00 0b 00 00 mov $0xb00,%ebx
20: 49 03 1e add (%r14),%rbx
23: 48 89 d8 mov %rbx,%rax
26: 48 c1 e8 03 shr $0x3,%rax
* 2a: 42 80 3c 28 00 cmpb $0x0,(%rax,%r13,1) <-- trapping instruction
2f: 74 08 je 0x39
31: 48 89 df mov %rbx,%rdi
34: e8 b1 ac 67 00 call 0x67acea
39: 4c 89 7d c8 mov %r15,-0x38(%rbp)
3d: 4d 85 ff test %r15,%r15