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

Status: upstream: reported syz repro on 2026/09/18 01:01
Subsystems: mmc usb
Labels: prio:high
[Documentation on labels]
Reported-by: syzbot+3ee5da0319ca17ef1f4e@syzkaller.appspotmail.com
First crash: 1d22h, last: 1h29m
✨ AI Jobs (1)
ID Workflow Result Correct Bug Created Started Finished Revision
bc0d9fc9 assessment-security DenialOfService: ✅ Exploitable: ✅ FilesystemTrigger: ❌ NetworkTrigger: ❌ PeripheralTrigger: ✅ RemoteTrigger: ❌ Unprivileged: ❌ UserNamespace: ❌ VMGuestTrigger: ❌ VMHostTrigger: ❌ KASAN: slab-use-after-free Read in rtsx_usb_ms_handle_req 2026/09/18 00:01 2026/09/18 00:01 2026/09/18 00:34 8d7d05f1
Discussions (2)
Title Replies (including bot) Last reply
[PATCH] memstick: core: reclaim the request before freeing a timed-out card 1 (1) 2026/09/19 10:04
[syzbot] [mmc?] [usb?] KASAN: slab-use-after-free Read in rtsx_usb_ms_handle_req 0 (1) 2026/09/18 01:01

Sample crash report:
=========
==================================================================
BUG: KASAN: slab-use-after-free in rtsx_usb_ms_issue_cmd drivers/memstick/host/rtsx_usb_ms.c:486 [inline]
BUG: KASAN: slab-use-after-free in rtsx_usb_ms_handle_req+0x17ff/0x1a00 drivers/memstick/host/rtsx_usb_ms.c:531
Read of size 1 at addr ffff8881082c8071 by task kworker/0:2/978

CPU: 0 UID: 0 PID: 978 Comm: kworker/0:2 Not tainted syzkaller #0 PREEMPT(lazy) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Workqueue: events rtsx_usb_ms_handle_req
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0x13d/0x4b0 mm/kasan/report.c:482
 kasan_report+0xdf/0x1c0 mm/kasan/report.c:595
 rtsx_usb_ms_issue_cmd drivers/memstick/host/rtsx_usb_ms.c:486 [inline]
 rtsx_usb_ms_handle_req+0x17ff/0x1a00 drivers/memstick/host/rtsx_usb_ms.c:531
 process_one_work+0xac7/0x1b10 kernel/workqueue.c:3396
 process_scheduled_works kernel/workqueue.c:3479 [inline]
 worker_thread+0x5ef/0xe50 kernel/workqueue.c:3560
 kthread+0x373/0x450 kernel/kthread.c:436
 ret_from_fork+0x69f/0xc90 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

Allocated by task 44:
 kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
 kasan_save_track+0x14/0x30 mm/kasan/common.c:78
 poison_kmalloc_redzone mm/kasan/common.c:398 [inline]
 __kasan_kmalloc+0x8f/0xa0 mm/kasan/common.c:415
 kasan_kmalloc include/linux/kasan.h:263 [inline]
 __kmalloc_cache_noprof+0x2d8/0x680 mm/slub.c:5563
 _kmalloc_noprof include/linux/slab.h:991 [inline]
 _kzalloc_noprof include/linux/slab.h:1312 [inline]
 memstick_alloc_card drivers/memstick/core/memstick.c:383 [inline]
 memstick_check+0x2c1/0x10d0 drivers/memstick/core/memstick.c:452
 process_one_work+0xac7/0x1b10 kernel/workqueue.c:3396
 process_scheduled_works kernel/workqueue.c:3479 [inline]
 worker_thread+0x5ef/0xe50 kernel/workqueue.c:3560
 kthread+0x373/0x450 kernel/kthread.c:436
 ret_from_fork+0x69f/0xc90 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

Freed by task 44:
 kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
 kasan_save_track+0x14/0x30 mm/kasan/common.c:78
 kasan_save_free_info+0x3b/0x70 mm/kasan/generic.c:584
 poison_slab_object mm/kasan/common.c:253 [inline]
 __kasan_slab_free+0x43/0x70 mm/kasan/common.c:285
 kasan_slab_free include/linux/kasan.h:235 [inline]
 slab_free_hook mm/slub.c:2748 [inline]
 slab_free mm/slub.c:6499 [inline]
 kfree+0x20c/0x650 mm/slub.c:6792
 memstick_alloc_card drivers/memstick/core/memstick.c:420 [inline]
 memstick_check+0x72b/0x10d0 drivers/memstick/core/memstick.c:452
 process_one_work+0xac7/0x1b10 kernel/workqueue.c:3396
 process_scheduled_works kernel/workqueue.c:3479 [inline]
 worker_thread+0x5ef/0xe50 kernel/workqueue.c:3560
 kthread+0x373/0x450 kernel/kthread.c:436
 ret_from_fork+0x69f/0xc90 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

The buggy address belongs to the object at ffff8881082c8000
 which belongs to the cache kmalloc-2k of size 2048
The buggy address is located 113 bytes inside of
 freed 2048-byte region [ffff8881082c8000, ffff8881082c8800)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff8881082c9000 pfn:0x1082c8
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0x200000000000240(workingset|head|node=0|zone=2)
page_type: f5(slab)
raw: 0200000000000240 ffff888100042000 ffff888100040948 ffff888100040948
raw: ffff8881082c9000 0000000000080001 00000000f5000000 0000000000000000
head: 0200000000000240 ffff888100042000 ffff888100040948 ffff888100040948
head: ffff8881082c9000 0000000000080001 00000000f5000000 0000000000000000
head: 0200000000000003 fffffffffffffe01 00000000ffffffff 00000000ffffffff
head: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000008
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 44, tgid 44 (kworker/u8:3), ts 87811495059
 set_page_owner include/linux/page_owner.h:33 [inline]
 post_alloc_hook+0xfd/0x120 mm/page_alloc.c:1871
 prep_new_page mm/page_alloc.c:1879 [inline]
 get_page_from_freelist+0xf4b/0x3440 mm/page_alloc.c:3943
 __alloc_frozen_pages_noprof+0x2d7/0x2f70 mm/page_alloc.c:5436
 alloc_slab_page mm/slub.c:3347 [inline]
 allocate_slab mm/slub.c:3462 [inline]
 new_slab+0xa9/0x6e0 mm/slub.c:3513
 refill_objects+0xe3/0x410 mm/slub.c:7410
 refill_sheaf mm/slub.c:2885 [inline]
 __pcs_replace_empty_main+0x35e/0x650 mm/slub.c:4774
 alloc_from_pcs mm/slub.c:4850 [inline]
 slab_alloc_node mm/slub.c:4984 [inline]
 __kmalloc_cache_noprof+0x4a1/0x680 mm/slub.c:5559
 _kmalloc_noprof include/linux/slab.h:991 [inline]
 _kzalloc_noprof include/linux/slab.h:1312 [inline]
 memstick_alloc_card drivers/memstick/core/memstick.c:383 [inline]
 memstick_check+0x2c1/0x10d0 drivers/memstick/core/memstick.c:452
 process_one_work+0xac7/0x1b10 kernel/workqueue.c:3396
 process_scheduled_works kernel/workqueue.c:3479 [inline]
 worker_thread+0x5ef/0xe50 kernel/workqueue.c:3560
 kthread+0x373/0x450 kernel/kthread.c:436
 ret_from_fork+0x69f/0xc90 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
page last free pid 38 tgid 38 ts 87363331372 stack trace:
 reset_page_owner include/linux/page_owner.h:26 [inline]
 __free_pages_prepare mm/page_alloc.c:1418 [inline]
 __free_frozen_pages+0x714/0xfc0 mm/page_alloc.c:2962
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x47/0xf0 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x1a0/0x1f0 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x4e/0x70 mm/kasan/common.c:350
 kasan_slab_alloc include/linux/kasan.h:253 [inline]
 slab_post_alloc_hook mm/slub.c:4683 [inline]
 slab_alloc_node mm/slub.c:4996 [inline]
 __do_kmalloc_node mm/slub.c:5413 [inline]
 __kmalloc_node_track_caller_noprof+0x2db/0x820 mm/slub.c:5545
 kvasprintf+0xbc/0x150 lib/kasprintf.c:25
 kvasprintf_const+0x66/0x1a0 lib/kasprintf.c:49
 kobject_set_name_vargs+0x5a/0x140 lib/kobject.c:274
 dev_set_name+0xc7/0x100 drivers/base/core.c:3564
 mmc_alloc_host+0x10a/0x930 drivers/mmc/core/host.c:542
 devm_mmc_alloc_host+0x4b/0xb0 drivers/mmc/core/host.c:597
 rtsx_usb_sdmmc_drv_probe+0x85/0x9a0 drivers/mmc/host/rtsx_usb_sdmmc.c:1391
 platform_probe+0x106/0x1d0 drivers/base/platform.c:1507
 call_driver_probe drivers/base/dd.c:628 [inline]
 really_probe+0x241/0xa60 drivers/base/dd.c:706
 __driver_probe_device+0x210/0x460 drivers/base/dd.c:868
 driver_probe_device+0x4a/0x140 drivers/base/dd.c:898

Memory state around the buggy address:
 ffff8881082c7f00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff8881082c7f80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff8881082c8000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                             ^
 ffff8881082c8080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8881082c8100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================

Crashes (23):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/09/19 06:35 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing d58dffe9ee2c 853b104b .config console log report syz / log [disk image] [vmlinux] [kernel image] ci2-upstream-usb KASAN: slab-use-after-free Read in rtsx_usb_ms_handle_req
2026/09/19 00:38 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing d58dffe9ee2c 853b104b .config console log report syz / log [disk image] [vmlinux] [kernel image] ci2-upstream-usb KASAN: slab-use-after-free Read in rtsx_usb_ms_handle_req
2026/09/18 04:04 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing d58dffe9ee2c 8d7d05f1 .config console log report syz / log [disk image] [vmlinux] [kernel image] ci2-upstream-usb KASAN: slab-use-after-free Read in rtsx_usb_ms_handle_req
2026/09/18 01:15 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing d58dffe9ee2c 8d7d05f1 .config console log report syz / log [disk image] [vmlinux] [kernel image] ci2-upstream-usb KASAN: slab-use-after-free Read in rtsx_usb_ms_handle_req
2026/09/17 22:13 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing d58dffe9ee2c 8d7d05f1 .config console log report syz / log [disk image] [vmlinux] [kernel image] ci2-upstream-usb KASAN: slab-use-after-free Read in rtsx_usb_ms_handle_req
2026/09/18 16:56 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing d58dffe9ee2c 853b104b .config console log report syz / log [disk image] [vmlinux] [kernel image] ci2-upstream-usb KASAN: slab-use-after-free Write in rtsx_usb_ms_handle_req
2026/09/19 09:18 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing d58dffe9ee2c 853b104b .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb KASAN: slab-use-after-free Read in rtsx_usb_ms_handle_req
2026/09/19 07:52 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing d58dffe9ee2c 853b104b .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb KASAN: slab-use-after-free Read in rtsx_usb_ms_handle_req
2026/09/19 01:46 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing d58dffe9ee2c 853b104b .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb KASAN: slab-use-after-free Read in rtsx_usb_ms_handle_req
2026/09/18 21:26 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing d58dffe9ee2c 853b104b .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb KASAN: slab-use-after-free Read in rtsx_usb_ms_handle_req
2026/09/18 19:50 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing d58dffe9ee2c 853b104b .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb KASAN: slab-use-after-free Read in rtsx_usb_ms_handle_req
2026/09/18 19:43 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing d58dffe9ee2c 853b104b .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb KASAN: slab-use-after-free Read in rtsx_usb_ms_handle_req
2026/09/18 19:28 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing d58dffe9ee2c 853b104b .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb KASAN: slab-use-after-free Read in rtsx_usb_ms_handle_req
2026/09/18 19:14 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing d58dffe9ee2c 853b104b .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb KASAN: slab-use-after-free Read in rtsx_usb_ms_handle_req
2026/09/18 17:08 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing d58dffe9ee2c 853b104b .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb KASAN: slab-use-after-free Read in rtsx_usb_ms_handle_req
2026/09/18 13:30 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing d58dffe9ee2c 853b104b .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb KASAN: slab-use-after-free Read in rtsx_usb_ms_handle_req
2026/09/18 12:36 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing d58dffe9ee2c 853b104b .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb KASAN: slab-use-after-free Read in rtsx_usb_ms_handle_req
2026/09/18 10:37 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing d58dffe9ee2c 853b104b .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb KASAN: slab-use-after-free Read in rtsx_usb_ms_handle_req
2026/09/18 02:07 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing d58dffe9ee2c 8d7d05f1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb KASAN: slab-use-after-free Read in rtsx_usb_ms_handle_req
2026/09/18 01:53 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing d58dffe9ee2c 8d7d05f1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb KASAN: slab-use-after-free Read in rtsx_usb_ms_handle_req
2026/09/17 11:54 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing 7198071826c4 95928915 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb KASAN: slab-use-after-free Read in rtsx_usb_ms_handle_req
2026/09/19 05:49 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing d58dffe9ee2c 853b104b .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb KASAN: slab-use-after-free Write in rtsx_usb_ms_handle_req
2026/09/18 09:59 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing d58dffe9ee2c 853b104b .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb KASAN: slab-use-after-free Write in rtsx_usb_ms_handle_req
* Struck through repros no longer work on HEAD.