KASAN: use-after-free Read in media_request_release

Status: upstream: reported C repro on 2026/08/18 08:54
Subsystems: media
Labels: prio:normal
[Documentation on labels]
Reported-by: syzbot+3910ee87c4ba0a51e3f9@syzkaller.appspotmail.com
First crash: 44d, last: 3d00h
▶ ▼ ✨ AI Patch Versions (1)
Version Stage Reported Report Link Job
1 moderation 2026/08/18 11:41 Discussion 3e0de0f5-6fdc-4089-9f0c-90a26880ecf4
▶ ▼ ✨ AI Jobs (12)
ID Workflow Result Correct Bug Created Started Finished Revision
7c9ab200 assessment-security DenialOfService: ✅ Exploitable: ✅ FilesystemTrigger: ❌ NetworkTrigger: ❌ PeripheralTrigger: ❌ RemoteTrigger: ❌ Unprivileged: ❌ UserNamespace: ❌ VMGuestTrigger: ❌ VMHostTrigger: ❌ ❓ KASAN: use-after-free Read in media_request_release 2026/09/03 00:00 2026/09/03 00:00 2026/09/03 00:49 9941e97d
3e0de0f5 patching ❓ KASAN: use-after-free Read in media_request_release 2026/08/18 09:50 2026/08/18 09:50 2026/08/18 11:41 1e72964b
93e08733 assessment-security 💥 KASAN: use-after-free Read in media_request_release 2026/08/18 00:00 2026/08/18 00:00 2026/08/18 00:00 1e72964b
3dcf32d8 repro-c Reproduced: ✅ ❓ KASAN: use-after-free Read in media_request_release 2026/08/17 19:37 2026/08/17 19:37 2026/08/17 20:25 1e72964b
870a7743 moderation 💥 KASAN: use-after-free Read in media_request_release 2026/08/14 00:00 2026/08/14 00:00 2026/08/14 00:00 0165196a
804cb98e assessment-security 💥 KASAN: use-after-free Read in media_request_release 2026/08/09 06:42 2026/08/09 06:42 2026/08/09 06:42 5d63f80b
5a87559c moderation 💥 KASAN: use-after-free Read in media_request_release 2026/08/09 06:42 2026/08/09 06:42 2026/08/09 06:42 5d63f80b
cc6a42d8 assessment-security 💥 KASAN: use-after-free Read in media_request_release 2026/08/04 00:20 2026/08/04 00:20 2026/08/04 00:20 cb1adeae
a539e49f moderation 💥 KASAN: use-after-free Read in media_request_release 2026/08/04 00:20 2026/08/04 00:20 2026/08/04 00:20 cb1adeae
6c2035b3 moderation 💥 KASAN: use-after-free Read in media_request_release 2026/08/03 00:00 2026/08/03 00:00 2026/08/03 00:00 e611ffe1
d6182690 assessment-security 💥 KASAN: use-after-free Read in media_request_release 2026/08/02 00:00 2026/08/02 00:00 2026/08/02 00:00 e611ffe1
2dbaca9a assessment-security 💥 KASAN: use-after-free Read in media_request_release 2026/07/31 00:00 2026/07/31 00:00 2026/07/31 00:00 aaffb173
▶ ▼ Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [media?] KASAN: use-after-free Read in media_request_release 1 (3) 2026/08/20 02:51
▶ ▼ Last patch testing requests (3)
Created Duration User Patch Repo Result
2026/09/08 20:15 12m retest repro upstream report job log log
2026/08/20 02:33 16m hdanton@sina.com patch upstream OK job log log
2026/08/18 08:25 13m nogikh@google.com upstream report job log log

Sample crash report:
vivid-023: unregistering video101
vivid-023: unregistering video102
vivid-023: unregistering v4l-touch23
==================================================================
BUG: KASAN: use-after-free in media_request_release+0x18f/0x1b0 drivers/media/mc/mc-request.c:74
Read of size 8 at addr ffff88802eeb03d0 by task syz-executor137/6019

CPU: 0 UID: 0 PID: 6019 Comm: syz-executor137 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
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
 media_request_release+0x18f/0x1b0 drivers/media/mc/mc-request.c:74
 kref_put include/linux/kref.h:65 [inline]
 media_request_put drivers/media/mc/mc-request.c:83 [inline]
 media_request_close+0x7e/0xc0 drivers/media/mc/mc-request.c:91
 __fput+0x3ff/0xb50 fs/file_table.c:512
 fput_close_sync+0x118/0x250 fs/file_table.c:617
 __do_sys_close fs/open.c:1560 [inline]
 __se_sys_close fs/open.c:1545 [inline]
 __x64_sys_close+0x8b/0x120 fs/open.c:1545
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f1498a6cd77
Code: 48 89 fa 4c 89 df e8 98 1d 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 fa 08 75 de e8 23 ff ff ff
RSP: 002b:00007ffe0f9add20 EFLAGS: 00000202 ORIG_RAX: 0000000000000003
RAX: ffffffffffffffda RBX: 0000555574a0d400 RCX: 00007f1498a6cd77
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000004
RBP: 0000555574a0f770 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 00007ffe0f9adf80
R13: 00007f1498aa2025 R14: 0000000000000003 R15: 0000000000000000
 </TASK>

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x2eeb0
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
page_type: f0(buddy)
raw: 00fff00000000000 ffffea0000bc7008 ffffea0000bd2008 0000000000000000
raw: 0000000000000000 0000000000000004 00000000f0000000 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as freed
page last allocated via order 4, migratetype Unmovable, gfp_mask 0x40dc0(GFP_KERNEL|__GFP_ZERO|__GFP_COMP), pid 1, tgid 1 (swapper/0), ts 13637122444, free_ts 68983659713
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0xfd/0x120 mm/page_alloc.c:1859
 prep_new_page mm/page_alloc.c:1867 [inline]
 get_page_from_freelist+0xf48/0x3530 mm/page_alloc.c:3946
 __alloc_frozen_pages_noprof+0x299/0x2dc0 mm/page_alloc.c:5304
 alloc_pages_mpol+0x1fb/0x540 mm/mempolicy.c:2490
 ___kmalloc_large_node+0xe5/0x120 mm/slub.c:5274
 __kmalloc_large_noprof+0x1c/0x70 mm/slub.c:5295
 _kmalloc_noprof include/linux/slab.h:985 [inline]
 _kzalloc_noprof include/linux/slab.h:1309 [inline]
 vivid_create_instance drivers/media/test-drivers/vivid/vivid-core.c:1817 [inline]
 vivid_probe+0x1f8/0x10d0 drivers/media/test-drivers/vivid/vivid-core.c:2095
 platform_probe+0x106/0x1d0 drivers/base/platform.c:1439
 call_driver_probe drivers/base/dd.c:628 [inline]
 really_probe+0x241/0xa60 drivers/base/dd.c:706
 __driver_probe_device+0x20e/0x450 drivers/base/dd.c:868
 driver_probe_device+0x4a/0x140 drivers/base/dd.c:898
 __driver_attach+0x21f/0x5b0 drivers/base/dd.c:1292
 bus_for_each_dev+0x13e/0x1d0 drivers/base/bus.c:383
 bus_add_driver+0x305/0x5b0 drivers/base/bus.c:763
 driver_register+0x1e2/0x360 drivers/base/driver.c:174
 vivid_init+0x527/0x6a0 drivers/media/test-drivers/vivid/vivid-core.c:2296
page last free pid 6019 tgid 6019 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 __free_pages_prepare mm/page_alloc.c:1406 [inline]
 __free_pages_ok+0x73b/0xfe0 mm/page_alloc.c:1584
 v4l2_device_release drivers/media/v4l2-core/v4l2-device.c:51 [inline]
 kref_put include/linux/kref.h:65 [inline]
 v4l2_device_put+0xa3/0xd0 drivers/media/v4l2-core/v4l2-device.c:56
 vivid_remove+0x3fd/0x560 drivers/media/test-drivers/vivid/vivid-core.c:2224
 platform_remove+0x5f/0x80 drivers/base/platform.c:1456
 device_remove+0xcb/0x180 drivers/base/dd.c:616
 __device_release_driver drivers/base/dd.c:1349 [inline]
 device_release_driver_internal+0x44e/0x620 drivers/base/dd.c:1372
 unbind_store+0xf8/0x110 drivers/base/bus.c:244
 drv_attr_store+0x74/0xb0 drivers/base/bus.c:125
 sysfs_kf_write+0xf2/0x150 fs/sysfs/file.c:145
 kernfs_fop_write_iter+0x3e0/0x5f0 fs/kernfs/file.c:345
 new_sync_write fs/read_write.c:595 [inline]
 vfs_write+0x6ac/0x1050 fs/read_write.c:687
 ksys_write+0x12a/0x250 fs/read_write.c:739
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffff88802eeb0280: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88802eeb0300: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff88802eeb0380: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                                                 ^
 ffff88802eeb0400: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88802eeb0480: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================

Crashes (4):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/08/18 08:53 upstream 0f23d56f17fd 4a865b71 .config console log report C ci-qemu-upstream KASAN: use-after-free Read in media_request_release
2026/07/29 04:59 upstream 3b5f4b83c4ab 4a865b71 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 KASAN: use-after-free Read in media_request_release
2026/08/25 20:13 upstream 818bebeb63dd a9a1fc32 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream general protection fault in media_request_release
2026/08/14 06:54 upstream 3aa1dcaa4f6f b13552fe .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream KASAN: slab-use-after-free Read in media_request_release
* Struck through repros no longer work on HEAD.