==================================================================
BUG: KASAN: use-after-free in __kernfs_remove+0x9dd/0xb30
Read of size 2 at addr ffff88801f7f8268 by task syz-executor.4/4885
CPU: 0 PID: 4885 Comm: syz-executor.4 Not tainted 6.0.0-rc3-next-20220829 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014
Call Trace:
dump_stack_lvl+0x8b/0xb3
print_report.cold+0x5e/0x5e5
kasan_report+0xb1/0x1c0
__kernfs_remove+0x9dd/0xb30
kernfs_remove_by_name_ns+0xa8/0x110
sysfs_slab_add+0x142/0x1f0
__kmem_cache_create+0x49d/0x600
kmem_cache_create_usercopy+0x1fd/0x2e0
p9_client_create+0xc85/0x1050
v9fs_session_init+0x1dd/0x1670
v9fs_mount+0xb9/0xbd0
legacy_get_tree+0x105/0x220
vfs_get_tree+0x8e/0x300
path_mount+0x1310/0x1e20
__x64_sys_mount+0x282/0x300
do_syscall_64+0x3b/0x90
entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f5d76f85b19
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:00007f5d744fb188 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f5d77098f60 RCX: 00007f5d76f85b19
RDX: 0000000020000040 RSI: 0000000020000000 RDI: 0000000000000000
RBP: 00007f5d76fdff6d R08: 0000000020000500 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fffcda177ff R14: 00007f5d744fb300 R15: 0000000000022000
Allocated by task 4879:
kasan_save_stack+0x1e/0x40
__kasan_slab_alloc+0x66/0x80
kmem_cache_alloc+0x1b1/0x3e0
__kernfs_new_node+0xd4/0x8c0
kernfs_create_dir_ns+0x9c/0x230
sysfs_create_dir_ns+0x127/0x290
kobject_add_internal+0x24c/0x8e0
kobject_init_and_add+0x101/0x160
sysfs_slab_add+0x165/0x1f0
__kmem_cache_create+0x49d/0x600
kmem_cache_create_usercopy+0x1fd/0x2e0
p9_client_create+0xc85/0x1050
v9fs_session_init+0x1dd/0x1670
v9fs_mount+0xb9/0xbd0
legacy_get_tree+0x105/0x220
vfs_get_tree+0x8e/0x300
path_mount+0x1310/0x1e20
__x64_sys_mount+0x282/0x300
do_syscall_64+0x3b/0x90
entry_SYSCALL_64_after_hwframe+0x63/0xcd
Freed by task 4885:
kasan_save_stack+0x1e/0x40
kasan_set_track+0x21/0x30
kasan_set_free_info+0x20/0x40
__kasan_slab_free+0x108/0x190
kmem_cache_free+0xf7/0x610
kernfs_put.part.0+0x2c7/0x540
kernfs_put+0x42/0x50
__kernfs_remove+0x7d4/0xb30
kernfs_remove_by_name_ns+0xa8/0x110
sysfs_slab_add+0x142/0x1f0
__kmem_cache_create+0x49d/0x600
kmem_cache_create_usercopy+0x1fd/0x2e0
p9_client_create+0xc85/0x1050
v9fs_session_init+0x1dd/0x1670
v9fs_mount+0xb9/0xbd0
legacy_get_tree+0x105/0x220
vfs_get_tree+0x8e/0x300
path_mount+0x1310/0x1e20
__x64_sys_mount+0x282/0x300
do_syscall_64+0x3b/0x90
entry_SYSCALL_64_after_hwframe+0x63/0xcd
The buggy address belongs to the object at ffff88801f7f81d0
which belongs to the cache kernfs_node_cache of size 168
The buggy address is located 152 bytes inside of
168-byte region [ffff88801f7f81d0, ffff88801f7f8278)
The buggy address belongs to the physical page:
page:00000000c8188ca8 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1f7f8
flags: 0x100000000000200(slab|node=0|zone=1)
raw: 0100000000000200 0000000000000000 dead000000000122 ffff88800847b8c0
raw: 0000000000000000 0000000000110011 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
Memory state around the buggy address:
ffff88801f7f8100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff88801f7f8180: fb fb fc fc fc fc fc fc fc fc fa fb fb fb fb fb
>ffff88801f7f8200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fc
^
ffff88801f7f8280: fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb fb
ffff88801f7f8300: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
==================================================================
------------[ cut here ]------------
WARNING: CPU: 0 PID: 4885 at fs/kernfs/dir.c:504 kernfs_get.part.0+0x6d/0x80
Modules linked in:
CPU: 0 PID: 4885 Comm: syz-executor.4 Tainted: G B 6.0.0-rc3-next-20220829 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014
RIP: 0010:kernfs_get.part.0+0x6d/0x80
Code: e8 b8 d9 a6 ff 85 ed 74 1c e8 ff dc a6 ff be 04 00 00 00 48 89 df e8 22 d6 d9 ff f0 ff 03 5b 5d e9 08 3d c1 02 e8 e3 dc a6 ff <0f> 0b eb db 48 89 df e8 97 d2 d9 ff eb c2 0f 1f 44 00 00 55 48 89
RSP: 0018:ffff888043bd7780 EFLAGS: 00010246
RAX: 0000000000040000 RBX: ffff88801f7f81d0 RCX: ffffc90002592000
RDX: 0000000000040000 RSI: ffffffff819efdfd RDI: 0000000000000005
RBP: 0000000000000000 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000000
R13: dffffc0000000000 R14: ffff88800d35eb20 R15: ffff88801f7f81d0
FS: 00007f5d744fb700(0000) GS:ffff88806ce00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2e028000 CR3: 0000000036a00000 CR4: 0000000000350ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
__kernfs_remove+0x34a/0xb30
kernfs_remove_by_name_ns+0xa8/0x110
sysfs_slab_add+0x142/0x1f0
__kmem_cache_create+0x49d/0x600
kmem_cache_create_usercopy+0x1fd/0x2e0
p9_client_create+0xc85/0x1050
v9fs_session_init+0x1dd/0x1670
v9fs_mount+0xb9/0xbd0
legacy_get_tree+0x105/0x220
vfs_get_tree+0x8e/0x300
path_mount+0x1310/0x1e20
__x64_sys_mount+0x282/0x300
do_syscall_64+0x3b/0x90
entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f5d76f85b19
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:00007f5d744fb188 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f5d77098f60 RCX: 00007f5d76f85b19
RDX: 0000000020000040 RSI: 0000000020000000 RDI: 0000000000000000
RBP: 00007f5d76fdff6d R08: 0000000020000500 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fffcda177ff R14: 00007f5d744fb300 R15: 0000000000022000
irq event stamp: 1049
hardirqs last enabled at (1049): [] asm_sysvec_apic_timer_interrupt+0x16/0x20
hardirqs last disabled at (1048): [] __do_softirq+0x6be/0x8d0
softirqs last enabled at (664): [] __irq_exit_rcu+0x11b/0x180
softirqs last disabled at (657): [] __irq_exit_rcu+0x11b/0x180
---[ end trace 0000000000000000 ]---
------------[ cut here ]------------
WARNING: CPU: 0 PID: 4885 at fs/kernfs/dir.c:473 __kernfs_remove+0x982/0xb30
Modules linked in:
CPU: 0 PID: 4885 Comm: syz-executor.4 Tainted: G B W 6.0.0-rc3-next-20220829 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014
RIP: 0010:__kernfs_remove+0x982/0xb30
Code: 80 3c 28 00 0f 85 f9 00 00 00 49 83 6c 24 68 01 4c 8b 63 30 e9 5f fd ff ff 48 8b 9d 28 ff ff ff e9 c0 f9 ff ff e8 5e b2 a6 ff <0f> 0b e9 bc fa ff ff e8 52 b2 a6 ff 4c 89 e2 48 b8 00 00 00 00 00
RSP: 0018:ffff888043bd7798 EFLAGS: 00010246
RAX: 0000000000040000 RBX: ffff88801f7f81d0 RCX: ffffc90002592000
RDX: 0000000000040000 RSI: ffffffff819f2882 RDI: 0000000000000001
RBP: ffff888043bd78c8 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000001 R12: 0000000000000001
R13: dffffc0000000000 R14: ffff88800d35eb20 R15: ffff888007c5b400
FS: 00007f5d744fb700(0000) GS:ffff88806ce00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2e028000 CR3: 0000000036a00000 CR4: 0000000000350ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
kernfs_remove_by_name_ns+0xa8/0x110
sysfs_slab_add+0x142/0x1f0
__kmem_cache_create+0x49d/0x600
kmem_cache_create_usercopy+0x1fd/0x2e0
p9_client_create+0xc85/0x1050
v9fs_session_init+0x1dd/0x1670
v9fs_mount+0xb9/0xbd0
legacy_get_tree+0x105/0x220
vfs_get_tree+0x8e/0x300
path_mount+0x1310/0x1e20
__x64_sys_mount+0x282/0x300
do_syscall_64+0x3b/0x90
entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f5d76f85b19
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:00007f5d744fb188 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f5d77098f60 RCX: 00007f5d76f85b19
RDX: 0000000020000040 RSI: 0000000020000000 RDI: 0000000000000000
RBP: 00007f5d76fdff6d R08: 0000000020000500 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fffcda177ff R14: 00007f5d744fb300 R15: 0000000000022000
irq event stamp: 1049
hardirqs last enabled at (1049): [] asm_sysvec_apic_timer_interrupt+0x16/0x20
hardirqs last disabled at (1048): [] __do_softirq+0x6be/0x8d0
softirqs last enabled at (664): [] __irq_exit_rcu+0x11b/0x180
softirqs last disabled at (657): [] __irq_exit_rcu+0x11b/0x180
---[ end trace 0000000000000000 ]---
random: crng reseeded on system resumption
Restarting kernel threads ... done.