KASAN: use-after-free Read in kernfs_add_one

Status: auto-obsoleted due to no activity on 2024/01/09 18:18
Reported-by: syzbot+2b1e09de67485a21a763@syzkaller.appspotmail.com
First crash: 1030d, last: 1030d
▶ ▼ Similar bugs (7)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KASAN: use-after-free Read in kernfs_add_one kernfs 19 C error inconclusive 39 837d 1768d 0/29 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) 19 1 827d 827d 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) 19 1 720d 720d 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 (4) origin:upstream missing-backport 19 C inconclusive 5 354d 581d 0/3 upstream: reported C repro on 2024/12/22 11:05
linux-5.15 KASAN: use-after-free Read in kernfs_add_one (2) 19 2 319d 395d 0/3 auto-obsoleted due to no activity on 2025/12/19 02:39
linux-6.1 KASAN: use-after-free Read in kernfs_add_one 19 1 1134d 1134d 0/3 auto-obsoleted due to no activity on 2023/09/26 01:13
upstream KASAN: slab-use-after-free Read in kernfs_add_one kernfs 19 6 506d 667d 0/29 auto-obsoleted due to no activity on 2025/06/15 10:44

Sample crash report:
usb 5-1: Direct firmware load for ueagle-atm/eagleII.fw failed with error -2
usb 5-1: Falling back to sysfs fallback for: ueagle-atm/eagleII.fw
==================================================================
BUG: KASAN: use-after-free in kernfs_root fs/kernfs/kernfs-internal.h:48 [inline]
BUG: KASAN: use-after-free in kernfs_add_one+0x491/0x640 fs/kernfs/dir.c:775
Read of size 8 at addr ffff8880701ba030 by task kworker/0:9/17146

CPU: 0 PID: 17146 Comm: kworker/0:9 Not tainted 5.15.133-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/06/2023
Workqueue: events request_firmware_work_func
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106
 print_address_description+0x63/0x3b0 mm/kasan/report.c:248
 __kasan_report mm/kasan/report.c:434 [inline]
 kasan_report+0x16b/0x1c0 mm/kasan/report.c:451
 kernfs_root fs/kernfs/kernfs-internal.h:48 [inline]
 kernfs_add_one+0x491/0x640 fs/kernfs/dir.c:775
 kernfs_create_dir_ns+0x1c0/0x230 fs/kernfs/dir.c:1003
 sysfs_create_dir_ns+0x185/0x390 fs/sysfs/dir.c:59
 create_dir lib/kobject.c:89 [inline]
 kobject_add_internal+0x6e0/0xe00 lib/kobject.c:263
 kobject_add_varg lib/kobject.c:398 [inline]
 kobject_add+0x14e/0x210 lib/kobject.c:450
 device_add+0x476/0xfd0 drivers/base/core.c:3329
 fw_load_sysfs_fallback drivers/base/firmware_loader/fallback.c:507 [inline]
 fw_load_from_user_helper drivers/base/firmware_loader/fallback.c:583 [inline]
 firmware_fallback_sysfs+0x3f0/0xc90 drivers/base/firmware_loader/fallback.c:659
 _request_firmware+0xbb1/0x1200 drivers/base/firmware_loader/main.c:848
 request_firmware_work_func+0x126/0x270 drivers/base/firmware_loader/main.c:1097
 process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2310
 worker_thread+0xaca/0x1280 kernel/workqueue.c:2457
 kthread+0x3f6/0x4f0 kernel/kthread.c:319
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298
 </TASK>

Allocated by task 17146:
 kasan_save_stack mm/kasan/common.c:38 [inline]
 kasan_set_track mm/kasan/common.c:46 [inline]
 set_alloc_info mm/kasan/common.c:434 [inline]
 __kasan_slab_alloc+0x8e/0xc0 mm/kasan/common.c:467
 kasan_slab_alloc include/linux/kasan.h:254 [inline]
 slab_post_alloc_hook+0x53/0x380 mm/slab.h:519
 slab_alloc_node mm/slub.c:3220 [inline]
 slab_alloc mm/slub.c:3228 [inline]
 kmem_cache_alloc+0xf3/0x280 mm/slub.c:3233
 kmem_cache_zalloc include/linux/slab.h:711 [inline]
 __kernfs_new_node+0xdb/0x750 fs/kernfs/dir.c:593
 kernfs_new_node fs/kernfs/dir.c:657 [inline]
 kernfs_create_dir_ns+0x90/0x230 fs/kernfs/dir.c:993
 sysfs_create_dir_ns+0x185/0x390 fs/sysfs/dir.c:59
 create_dir lib/kobject.c:89 [inline]
 kobject_add_internal+0x6e0/0xe00 lib/kobject.c:263
 kobject_add_varg lib/kobject.c:398 [inline]
 kobject_add+0x14e/0x210 lib/kobject.c:450
 device_add+0x476/0xfd0 drivers/base/core.c:3329
 fw_load_sysfs_fallback drivers/base/firmware_loader/fallback.c:507 [inline]
 fw_load_from_user_helper drivers/base/firmware_loader/fallback.c:583 [inline]
 firmware_fallback_sysfs+0x3f0/0xc90 drivers/base/firmware_loader/fallback.c:659
 _request_firmware+0xbb1/0x1200 drivers/base/firmware_loader/main.c:848
 request_firmware_work_func+0x126/0x270 drivers/base/firmware_loader/main.c:1097
 process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2310
 worker_thread+0xaca/0x1280 kernel/workqueue.c:2457
 kthread+0x3f6/0x4f0 kernel/kthread.c:319
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298

Freed by task 12528:
 kasan_save_stack mm/kasan/common.c:38 [inline]
 kasan_set_track+0x4b/0x80 mm/kasan/common.c:46
 kasan_set_free_info+0x1f/0x40 mm/kasan/generic.c:360
 ____kasan_slab_free+0xd8/0x120 mm/kasan/common.c:366
 kasan_slab_free include/linux/kasan.h:230 [inline]
 slab_free_hook mm/slub.c:1705 [inline]
 slab_free_freelist_hook+0xdd/0x160 mm/slub.c:1731
 slab_free mm/slub.c:3499 [inline]
 kmem_cache_free+0x91/0x1f0 mm/slub.c:3515
 kernfs_put+0x325/0x4a0 fs/kernfs/dir.c:547
 __kernfs_remove+0x99e/0xc80 fs/kernfs/dir.c:1381
 kernfs_remove+0x1d/0x30 fs/kernfs/dir.c:1394
 __kobject_del+0xe2/0x310 lib/kobject.c:628
 kobject_del+0x41/0x60 lib/kobject.c:651
 device_del+0x9fe/0xbd0 drivers/base/core.c:3594
 usb_disconnect+0x58f/0x8c0 drivers/usb/core/hub.c:2257
 hub_port_connect drivers/usb/core/hub.c:5262 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5558 [inline]
 port_event drivers/usb/core/hub.c:5704 [inline]
 hub_event+0x1d58/0x54b0 drivers/usb/core/hub.c:5786
 process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2310
 process_scheduled_works kernel/workqueue.c:2373 [inline]
 worker_thread+0xdcf/0x1280 kernel/workqueue.c:2459
 kthread+0x3f6/0x4f0 kernel/kthread.c:319
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298

The buggy address belongs to the object at ffff8880701ba000
 which belongs to the cache kernfs_node_cache of size 168
The buggy address is located 48 bytes inside of
 168-byte region [ffff8880701ba000, ffff8880701ba0a8)
The buggy address belongs to the page:
page:ffffea0001c06e80 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x701ba
flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000200 0000000000000000 dead000000000122 ffff888011dddb40
raw: 0000000000000000 0000000080110011 00000001ffffffff 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 0x112cc0(GFP_USER|__GFP_NOWARN|__GFP_NORETRY), pid 17146, ts 2575486055782, free_ts 2575343735190
 prep_new_page mm/page_alloc.c:2426 [inline]
 get_page_from_freelist+0x322a/0x33c0 mm/page_alloc.c:4159
 __alloc_pages+0x272/0x700 mm/page_alloc.c:5421
 alloc_slab_page mm/slub.c:1775 [inline]
 allocate_slab mm/slub.c:1912 [inline]
 new_slab+0xbb/0x4b0 mm/slub.c:1975
 ___slab_alloc+0x6f6/0xe10 mm/slub.c:3008
 __slab_alloc mm/slub.c:3095 [inline]
 slab_alloc_node mm/slub.c:3186 [inline]
 slab_alloc mm/slub.c:3228 [inline]
 kmem_cache_alloc+0x18e/0x280 mm/slub.c:3233
 kmem_cache_zalloc include/linux/slab.h:711 [inline]
 __kernfs_new_node+0xdb/0x750 fs/kernfs/dir.c:593
 kernfs_new_node fs/kernfs/dir.c:657 [inline]
 kernfs_create_dir_ns+0x90/0x230 fs/kernfs/dir.c:993
 sysfs_create_dir_ns+0x185/0x390 fs/sysfs/dir.c:59
 create_dir lib/kobject.c:89 [inline]
 kobject_add_internal+0x6e0/0xe00 lib/kobject.c:263
 kobject_add_varg lib/kobject.c:398 [inline]
 kobject_add+0x14e/0x210 lib/kobject.c:450
 device_add+0x476/0xfd0 drivers/base/core.c:3329
 fw_load_sysfs_fallback drivers/base/firmware_loader/fallback.c:507 [inline]
 fw_load_from_user_helper drivers/base/firmware_loader/fallback.c:583 [inline]
 firmware_fallback_sysfs+0x3f0/0xc90 drivers/base/firmware_loader/fallback.c:659
 _request_firmware+0xbb1/0x1200 drivers/base/firmware_loader/main.c:848
 request_firmware_work_func+0x126/0x270 drivers/base/firmware_loader/main.c:1097
 process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2310
 worker_thread+0xaca/0x1280 kernel/workqueue.c:2457
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1340 [inline]
 free_pcp_prepare mm/page_alloc.c:1391 [inline]
 free_unref_page_prepare+0xc34/0xcf0 mm/page_alloc.c:3317
 free_unref_page+0x95/0x2d0 mm/page_alloc.c:3396
 __vunmap+0x8d4/0xa20 mm/vmalloc.c:2621
 free_work+0x57/0x80 mm/vmalloc.c:95
 process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2310
 worker_thread+0xaca/0x1280 kernel/workqueue.c:2457
 kthread+0x3f6/0x4f0 kernel/kthread.c:319
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298

Memory state around the buggy address:
 ffff8880701b9f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8880701b9f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff8880701ba000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                     ^
 ffff8880701ba080: fb fb fb fb fb fc fc fc fc fc fc fc fc fc fc fc
 ffff8880701ba100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2023/09/29 22:36 linux-5.15.y b911329317b4 8e26a358 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in kernfs_add_one
* Struck through repros no longer work on HEAD.