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

Title	Replies (including bot)	Last reply
[syzbot] [scsi?] [usb?] KASAN: slab-use-after-free Read in sg_release	0 (1)	2024/11/06 11:47
Kernel	Title	Repro	Cause bisect	Fix bisect	Count	Last	Reported	Patched	Status
upstream	KASAN: use-after-free Read in sg_release scsi				1	1189d	1189d	0/28	auto-closed as invalid on 2021/10/04 20:06
==================================================================
BUG: KASAN: slab-use-after-free in lock_release+0x151/0xa30 kernel/locking/lockdep.c:5838
Read of size 8 at addr ffff8880312a38c0 by task syz.2.335/8457

CPU: 1 UID: 0 PID: 8457 Comm: syz.2.335 Not tainted 6.12.0-rc5-syzkaller-00299-g11066801dd4b #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
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
 lock_release+0x151/0xa30 kernel/locking/lockdep.c:5838
 __mutex_unlock_slowpath+0xe2/0x750 kernel/locking/mutex.c:912
 sg_release+0x1f4/0x2e0 drivers/scsi/sg.c:407
 __fput+0x23f/0x880 fs/file_table.c:431
 task_work_run+0x24f/0x310 kernel/task_work.c:239
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:114 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0x168/0x370 kernel/entry/common.c:218
 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f312af7e719
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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffdb5d17628 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 00007f312b137a80 RCX: 00007f312af7e719
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 00007f312b137a80 R08: 0000000000000000 R09: 00007ffdb5d1791f
R10: 000000000003fdc8 R11: 0000000000000246 R12: 000000000005f4a4
R13: 00007ffdb5d17730 R14: 0000000000000032 R15: ffffffffffffffff
 </TASK>

Allocated by task 7133:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
 poison_kmalloc_redzone mm/kasan/common.c:377 [inline]
 __kasan_kmalloc+0x98/0xb0 mm/kasan/common.c:394
 kasan_kmalloc include/linux/kasan.h:257 [inline]
 __kmalloc_cache_noprof+0x19c/0x2c0 mm/slub.c:4295
 kmalloc_noprof include/linux/slab.h:878 [inline]
 kzalloc_noprof include/linux/slab.h:1014 [inline]
 sg_alloc drivers/scsi/sg.c:1444 [inline]
 sg_add_device+0x139/0xb10 drivers/scsi/sg.c:1518
 device_add+0xa1f/0xbf0 drivers/base/core.c:3698
 scsi_sysfs_add_sdev+0x306/0x5a0 drivers/scsi/scsi_sysfs.c:1435
 scsi_sysfs_add_devices drivers/scsi/scsi_scan.c:1896 [inline]
 scsi_finish_async_scan drivers/scsi/scsi_scan.c:1981 [inline]
 do_scan_async+0x42a/0x7a0 drivers/scsi/scsi_scan.c:2024
 async_run_entry_fn+0xa8/0x420 kernel/async.c:129
 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 6000:
 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]
 kfree+0x1a0/0x440 mm/slub.c:4727
 kref_put include/linux/kref.h:65 [inline]
 sg_remove_sfp_usercontext+0x331/0x4d0 drivers/scsi/sg.c:2238
 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 ffff8880312a3800
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 192 bytes inside of
 freed 512-byte region [ffff8880312a3800, ffff8880312a3a00)

The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff8880312a2000 pfn:0x312a0
head: order:2 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0xfff00000000240(workingset|head|node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000240 ffff88801ac41c80 ffffea00010c8910 ffffea0001fcb310
raw: ffff8880312a2000 000000000010000d 00000001f5000000 0000000000000000
head: 00fff00000000240 ffff88801ac41c80 ffffea00010c8910 ffffea0001fcb310
head: ffff8880312a2000 000000000010000d 00000001f5000000 0000000000000000
head: 00fff00000000002 ffffea0000c4a801 ffffffffffffffff 0000000000000000
head: ffff888000000004 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 2, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5224, tgid 5224 (udevd), ts 31207973672, free_ts 31004401902
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1f3/0x230 mm/page_alloc.c:1537
 prep_new_page mm/page_alloc.c:1545 [inline]
 get_page_from_freelist+0x303f/0x3190 mm/page_alloc.c:3457
 __alloc_pages_noprof+0x292/0x710 mm/page_alloc.c:4733
 alloc_pages_mpol_noprof+0x3e8/0x680 mm/mempolicy.c:2265
 alloc_slab_page+0x6a/0x120 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]
 __kmalloc_cache_noprof+0x1d5/0x2c0 mm/slub.c:4290
 kmalloc_noprof include/linux/slab.h:878 [inline]
 kzalloc_noprof include/linux/slab.h:1014 [inline]
 kernfs_fop_open+0x3e0/0xd10 fs/kernfs/file.c:623
 do_dentry_open+0x978/0x1460 fs/open.c:958
 vfs_open+0x3e/0x330 fs/open.c:1088
 do_open fs/namei.c:3774 [inline]
 path_openat+0x2c84/0x3590 fs/namei.c:3933
 do_filp_open+0x235/0x490 fs/namei.c:3960
 do_sys_openat2+0x13e/0x1d0 fs/open.c:1415
 do_sys_open fs/open.c:1430 [inline]
 __do_sys_openat fs/open.c:1446 [inline]
 __se_sys_openat fs/open.c:1441 [inline]
 __x64_sys_openat+0x247/0x2a0 fs/open.c:1441
page last free pid 16 tgid 16 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1108 [inline]
 free_unref_page+0xcfb/0xf20 mm/page_alloc.c:2638
 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
 run_ksoftirqd+0xca/0x130 kernel/softirq.c:927
 smpboot_thread_fn+0x544/0xa30 kernel/smpboot.c:164
 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:
 ffff8880312a3780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8880312a3800: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8880312a3880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                           ^
 ffff8880312a3900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8880312a3980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================