From: syzbot <syzbot+3910ee87c4ba0a51e3f9@syzkaller.appspotmail.com>
To: linux-kernel@vger.kernel.org, linux-media@vger.kernel.org,
syzkaller-bugs@googlegroups.com
Subject: [syzbot] [media?] KASAN: use-after-free Read in media_request_release
Date: Tue, 18 Aug 2026 01:54:33 -0700 [thread overview]
Message-ID: <6a841dc9.4d75e56a.c9a88.000e.GAE@google.com> (raw)
Hello,
syzbot found the following issue on:
HEAD commit: 0f23d56f17fd Merge tag 'linux_kselftest-next-7.3-rc1' of g..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=14185a25580000
kernel config: https://syzkaller.appspot.com/x/.config?x=65bfb7732ae5a736
dashboard link: https://syzkaller.appspot.com/bug?extid=3910ee87c4ba0a51e3f9
compiler: gcc (Debian 14.2.0-19) 14.2.0, GNU ld (GNU Binutils for Debian) 2.44
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=12185a25580000
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+3910ee87c4ba0a51e3f9@syzkaller.appspotmail.com
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
==================================================================
---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzkaller@googlegroups.com.
syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title
If you want syzbot to run the reproducer, reply with:
#syz test: git://repo/address.git branch-or-commit-hash
If you attach or paste a git patch, syzbot will apply it before testing.
If you want to overwrite report's subsystems, reply with:
#syz set subsystems: new-subsystem
(See the list of subsystem names on the web dashboard)
If the report is a duplicate of another one, reply with:
#syz dup: exact-subject-of-another-report
If you want to undo deduplication, reply with:
#syz undup
reply other threads:[~2026-08-18 8:54 UTC|newest]
Thread overview: [no followups] expand[flat|nested] mbox.gz Atom feed
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=6a841dc9.4d75e56a.c9a88.000e.GAE@google.com \
--to=syzbot+3910ee87c4ba0a51e3f9@syzkaller.appspotmail.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-media@vger.kernel.org \
--cc=syzkaller-bugs@googlegroups.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.