syzbot


KASAN: slab-use-after-free Read in kernfs_add_one

Status: upstream: reported on 2024/09/27 15:10
Subsystems: kernfs
[Documentation on labels]
Reported-by: syzbot+81380e5b57bacce8a9f6@syzkaller.appspotmail.com
First crash: 73d, last: 5d11h
Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [kernfs?] KASAN: slab-use-after-free Read in kernfs_add_one 0 (1) 2024/09/27 15:10
Similar bugs (5)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KASAN: use-after-free Read in kernfs_add_one kernfs C error inconclusive 39 225d 1155d 0/28 auto-obsoleted due to no activity on 2024/08/14 07:44
linux-6.1 KASAN: use-after-free Read in kernfs_add_one (2) 1 215d 215d 0/3 auto-obsoleted due to no activity on 2024/07/29 04:04
linux-6.1 KASAN: use-after-free Read in kernfs_add_one (3) 1 107d 107d 0/3 auto-obsoleted due to no activity on 2024/11/13 12:08
linux-6.1 KASAN: use-after-free Read in kernfs_add_one 1 522d 522d 0/3 auto-obsoleted due to no activity on 2023/09/26 01:13
linux-5.15 KASAN: use-after-free Read in kernfs_add_one 1 418d 418d 0/3 auto-obsoleted due to no activity on 2024/01/09 18:18

Sample crash report:
==================================================================
BUG: KASAN: slab-use-after-free in kernfs_root fs/kernfs/kernfs-internal.h:70 [inline]
BUG: KASAN: slab-use-after-free in kernfs_add_one+0x447/0x8b0 fs/kernfs/dir.c:818
Read of size 8 at addr ffff8880357ddd50 by task kworker/0:1/12145

CPU: 0 UID: 0 PID: 12145 Comm: kworker/0:1 Not tainted 6.12.0-rc7-syzkaller-00125-gcfaaa7d010d1 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/30/2024
Workqueue: events request_firmware_work_func
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:377 [inline]
 print_report+0x169/0x550 mm/kasan/report.c:488
 kasan_report+0x143/0x180 mm/kasan/report.c:601
 kernfs_root fs/kernfs/kernfs-internal.h:70 [inline]
 kernfs_add_one+0x447/0x8b0 fs/kernfs/dir.c:818
 kernfs_create_dir_ns+0xd9/0x120 fs/kernfs/dir.c:1071
 sysfs_create_dir_ns+0x189/0x3a0 fs/sysfs/dir.c:59
 create_dir lib/kobject.c:73 [inline]
 kobject_add_internal+0x435/0x8d0 lib/kobject.c:240
 kobject_add_varg lib/kobject.c:374 [inline]
 kobject_add+0x152/0x220 lib/kobject.c:426
 class_dir_create_and_add drivers/base/core.c:3215 [inline]
 get_device_parent+0x391/0x410 drivers/base/core.c:3266
 device_add+0x325/0xbf0 drivers/base/core.c:3596
 fw_load_sysfs_fallback drivers/base/firmware_loader/fallback.c:86 [inline]
 fw_load_from_user_helper drivers/base/firmware_loader/fallback.c:162 [inline]
 firmware_fallback_sysfs+0x307/0x9e0 drivers/base/firmware_loader/fallback.c:238
 _request_firmware+0xdf7/0x13b0 drivers/base/firmware_loader/main.c:942
 request_firmware_work_func+0x12a/0x280 drivers/base/firmware_loader/main.c:1195
 process_one_work kernel/workqueue.c:3229 [inline]
 process_scheduled_works+0xa63/0x1850 kernel/workqueue.c:3310
 worker_thread+0x870/0xd30 kernel/workqueue.c:3391
 kthread+0x2f0/0x390 kernel/kthread.c:389
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>

Allocated by task 12145:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
 unpoison_slab_object mm/kasan/common.c:319 [inline]
 __kasan_slab_alloc+0x66/0x80 mm/kasan/common.c:345
 kasan_slab_alloc include/linux/kasan.h:247 [inline]
 slab_post_alloc_hook mm/slub.c:4085 [inline]
 slab_alloc_node mm/slub.c:4134 [inline]
 kmem_cache_alloc_noprof+0x135/0x2a0 mm/slub.c:4141
 __kernfs_new_node+0xd8/0x870 fs/kernfs/dir.c:624
 kernfs_new_node+0x137/0x240 fs/kernfs/dir.c:700
 kernfs_create_dir_ns+0x43/0x120 fs/kernfs/dir.c:1061
 sysfs_create_dir_ns+0x189/0x3a0 fs/sysfs/dir.c:59
 create_dir lib/kobject.c:73 [inline]
 kobject_add_internal+0x435/0x8d0 lib/kobject.c:240
 kobject_add_varg lib/kobject.c:374 [inline]
 kobject_add+0x152/0x220 lib/kobject.c:426
 class_dir_create_and_add drivers/base/core.c:3215 [inline]
 get_device_parent+0x391/0x410 drivers/base/core.c:3266
 device_add+0x325/0xbf0 drivers/base/core.c:3596
 fw_load_sysfs_fallback drivers/base/firmware_loader/fallback.c:86 [inline]
 fw_load_from_user_helper drivers/base/firmware_loader/fallback.c:162 [inline]
 firmware_fallback_sysfs+0x307/0x9e0 drivers/base/firmware_loader/fallback.c:238
 _request_firmware+0xdf7/0x13b0 drivers/base/firmware_loader/main.c:942
 request_firmware_work_func+0x12a/0x280 drivers/base/firmware_loader/main.c:1195
 process_one_work kernel/workqueue.c:3229 [inline]
 process_scheduled_works+0xa63/0x1850 kernel/workqueue.c:3310
 worker_thread+0x870/0xd30 kernel/workqueue.c:3391
 kthread+0x2f0/0x390 kernel/kthread.c:389
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

Freed by task 21840:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:579
 poison_slab_object mm/kasan/common.c:247 [inline]
 __kasan_slab_free+0x59/0x70 mm/kasan/common.c:264
 kasan_slab_free include/linux/kasan.h:230 [inline]
 slab_free_hook mm/slub.c:2342 [inline]
 slab_free mm/slub.c:4579 [inline]
 kmem_cache_free+0x1a2/0x420 mm/slub.c:4681
 rcu_do_batch kernel/rcu/tree.c:2567 [inline]
 rcu_core+0xaaa/0x17a0 kernel/rcu/tree.c:2823
 handle_softirqs+0x2c5/0x980 kernel/softirq.c:554
 __do_softirq kernel/softirq.c:588 [inline]
 invoke_softirq kernel/softirq.c:428 [inline]
 __irq_exit_rcu+0xf4/0x1c0 kernel/softirq.c:637
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:649
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline]
 sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1049
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702

Last potentially related work creation:
 kasan_save_stack+0x3f/0x60 mm/kasan/common.c:47
 __kasan_record_aux_stack+0xac/0xc0 mm/kasan/generic.c:541
 __call_rcu_common kernel/rcu/tree.c:3086 [inline]
 call_rcu+0x167/0xa70 kernel/rcu/tree.c:3190
 kernfs_put+0x1dc/0x370 fs/kernfs/dir.c:578
 __kernfs_remove+0x768/0x870 fs/kernfs/dir.c:1508
 kernfs_remove+0x7a/0xa0 fs/kernfs/dir.c:1528
 __kobject_del+0xe2/0x310 lib/kobject.c:604
 kobject_del+0x45/0x60 lib/kobject.c:627
 device_del+0x7ff/0x9b0 drivers/base/core.c:3881
 usb_disconnect+0x60b/0x950 drivers/usb/core/hub.c:2332
 hub_port_connect drivers/usb/core/hub.c:5361 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5661 [inline]
 port_event drivers/usb/core/hub.c:5821 [inline]
 hub_event+0x1ebc/0x5150 drivers/usb/core/hub.c:5903
 process_one_work kernel/workqueue.c:3229 [inline]
 process_scheduled_works+0xa63/0x1850 kernel/workqueue.c:3310
 worker_thread+0x870/0xd30 kernel/workqueue.c:3391
 kthread+0x2f0/0x390 kernel/kthread.c:389
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

The buggy address belongs to the object at ffff8880357ddd20
 which belongs to the cache kernfs_node_cache of size 176
The buggy address is located 48 bytes inside of
 freed 176-byte region [ffff8880357ddd20, ffff8880357dddd0)

The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x357dd
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000000 ffff888140ab0000 dead000000000122 0000000000000000
raw: 0000000000000000 0000000080110011 00000001f5000000 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x52cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 19709, tgid 19709 (kworker/0:3), ts 1564533240226, free_ts 1564096572011
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1f3/0x230 mm/page_alloc.c:1556
 prep_new_page mm/page_alloc.c:1564 [inline]
 get_page_from_freelist+0x363e/0x3790 mm/page_alloc.c:3474
 __alloc_pages_noprof+0x292/0x710 mm/page_alloc.c:4750
 alloc_pages_mpol_noprof+0x3e8/0x680 mm/mempolicy.c:2265
 alloc_slab_page+0x6a/0x140 mm/slub.c:2412
 allocate_slab+0x5a/0x2f0 mm/slub.c:2578
 new_slab mm/slub.c:2631 [inline]
 ___slab_alloc+0xcd1/0x14b0 mm/slub.c:3818
 __slab_alloc+0x58/0xa0 mm/slub.c:3908
 __slab_alloc_node mm/slub.c:3961 [inline]
 slab_alloc_node mm/slub.c:4122 [inline]
 kmem_cache_alloc_noprof+0x1c1/0x2a0 mm/slub.c:4141
 __kernfs_new_node+0xd8/0x870 fs/kernfs/dir.c:624
 kernfs_new_node+0x137/0x240 fs/kernfs/dir.c:700
 __kernfs_create_file+0x49/0x2e0 fs/kernfs/file.c:1034
 sysfs_add_file_mode_ns+0x24a/0x310 fs/sysfs/file.c:307
 create_files fs/sysfs/group.c:76 [inline]
 internal_create_group+0x7a7/0x11d0 fs/sysfs/group.c:180
 internal_create_groups fs/sysfs/group.c:220 [inline]
 sysfs_create_groups+0x56/0x120 fs/sysfs/group.c:246
 device_add_groups drivers/base/core.c:2819 [inline]
 device_add_attrs+0x199/0x600 drivers/base/core.c:2894
page last free pid 18929 tgid 18929 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1127 [inline]
 free_unref_page+0xded/0x1130 mm/page_alloc.c:2657
 bpf_ringbuf_free kernel/bpf/ringbuf.c:226 [inline]
 ringbuf_map_free+0xc2/0x120 kernel/bpf/ringbuf.c:235
 bpf_map_free kernel/bpf/syscall.c:744 [inline]
 bpf_map_free_deferred+0xe4/0x100 kernel/bpf/syscall.c:768
 process_one_work kernel/workqueue.c:3229 [inline]
 process_scheduled_works+0xa63/0x1850 kernel/workqueue.c:3310
 worker_thread+0x870/0xd30 kernel/workqueue.c:3391
 kthread+0x2f0/0x390 kernel/kthread.c:389
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

Memory state around the buggy address:
 ffff8880357ddc00: fc fc fc fc fc fc fa fb fb fb fb fb fb fb fb fb
 ffff8880357ddc80: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
>ffff8880357ddd00: fc fc fc fc fa fb fb fb fb fb fb fb fb fb fb fb
                                                 ^
 ffff8880357ddd80: fb fb fb fb fb fb fb fb fb fb fc fc fc fc fc fc
 ffff8880357dde00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================

Crashes (4):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/11/15 18:41 upstream cfaaa7d010d1 f6ede3a3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root KASAN: slab-use-after-free Read in kernfs_add_one
2024/11/15 08:50 upstream cfaaa7d010d1 f6ede3a3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce KASAN: slab-use-after-free Read in kernfs_add_one
2024/10/31 21:56 upstream 0fc810ae3ae1 96eb609f .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce KASAN: slab-use-after-free Read in kernfs_add_one
2024/09/08 10:37 upstream d1f2d51b711a 9750182a .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-386 KASAN: slab-use-after-free Read in kernfs_add_one
* Struck through repros no longer work on HEAD.