KASAN: slab-use-after-free Read in load_firmware_cb (2)

Status: upstream: reported C repro on 2025/03/30 07:21
Subsystems: usb media
[Documentation on labels]
Reported-by: syzbot+db4326df1b9af04f68fc@syzkaller.appspotmail.com
First crash: 486d, last: 34m
▶ ▼ ✨ AI Jobs (8)
ID Workflow Result Correct Bug Created Started Finished Revision Error
7e08f5b2 patching 💥 KASAN: slab-use-after-free Read in load_firmware_cb (2) 2026/07/20 10:13 2026/07/20 10:13 2026/07/20 10:46 de6a700d 
Kernel failed to boot: can't ssh into the instance
failed to run ["ssh" "-p" "22" "-F" "/dev/null" "-o" "UserKnownHostsFile=/dev/null" "-o" "IdentitiesOnly=yes" "-o" "BatchMode=yes" "-o" "StrictHostKe...
truncated to first 200 bytes; open job for full error
7de25478 patching 💥 KASAN: slab-use-after-free Read in load_firmware_cb (2) 2026/07/17 14:22 2026/07/17 14:22 2026/07/17 14:41 8aaff637 
failed to run ["make" "KERNELVERSION=syzkaller" "KERNELRELEASE=syzkaller" "LOCALVERSION=-syzkaller" "-j" "32" "ARCH=arm64" "CROSS_COMPILE=aarch64-linux-gnu-" "CC=ccache clang" "LD=ld.lld" "O=/app/work...
truncated to first 200 bytes; open job for full error
3f8f21b6 assessment-security 💥 KASAN: slab-use-after-free Read in load_firmware_cb (2) 2026/07/05 02:36 2026/07/05 02:36 2026/07/05 02:36 93f57954 
failed to run ["git" "-c" "core.hooksPath=/dev/null" "fetch" "--force" "--tags" "433dfd5a8a5d80bbf0669b14e9ed908911a52dd6" "05c93f3395ed8b4459ec64f25c2ad41437e56f2b"]: exit status 128
fatal: remote er...
truncated to first 200 bytes; open job for full error
08c3d9aa assessment-security 💥 KASAN: slab-use-after-free Read in load_firmware_cb (2) 2026/06/18 02:24 2026/06/18 02:24 2026/06/18 02:24 b62b3ded 
failed to run ["git" "-c" "core.hooksPath=/dev/null" "fetch" "--force" "--tags" "433dfd5a8a5d80bbf0669b14e9ed908911a52dd6" "05c93f3395ed8b4459ec64f25c2ad41437e56f2b"]: exit status 128
fatal: remote er...
truncated to first 200 bytes; open job for full error
79d389ff assessment-security 💥 KASAN: slab-use-after-free Read in load_firmware_cb (2) 2026/06/09 22:36 2026/06/09 22:36 2026/06/09 22:36 c36c07f6 
failed to run ["git" "-c" "core.hooksPath=/dev/null" "fetch" "--force" "--tags" "433dfd5a8a5d80bbf0669b14e9ed908911a52dd6" "05c93f3395ed8b4459ec64f25c2ad41437e56f2b"]: exit status 128
fatal: remote er...
truncated to first 200 bytes; open job for full error
1588fde5 assessment-security 💥 KASAN: slab-use-after-free Read in load_firmware_cb (2) 2026/06/03 00:08 2026/06/03 00:08 2026/06/03 00:08 62fe1528 
failed to run ["git" "-c" "core.hooksPath=/dev/null" "fetch" "--force" "--tags" "433dfd5a8a5d80bbf0669b14e9ed908911a52dd6" "05c93f3395ed8b4459ec64f25c2ad41437e56f2b"]: exit status 128
fatal: remote er...
truncated to first 200 bytes; open job for full error
5c011c30 assessment-security 💥 KASAN: slab-use-after-free Read in load_firmware_cb (2) 2026/05/31 21:45 2026/05/31 21:45 2026/05/31 21:45 6b4a8443 
failed to run ["git" "-c" "core.hooksPath=/dev/null" "fetch" "--force" "--tags" "433dfd5a8a5d80bbf0669b14e9ed908911a52dd6" "05c93f3395ed8b4459ec64f25c2ad41437e56f2b"]: exit status 128
fatal: remote er...
truncated to first 200 bytes; open job for full error
4308d472 assessment-security 💥 KASAN: slab-use-after-free Read in load_firmware_cb (2) 2026/05/15 07:04 2026/05/15 07:04 2026/05/15 07:04 6ccb967e 
failed to run ["git" "-c" "core.hooksPath=/dev/null" "fetch" "--force" "--tags" "433dfd5a8a5d80bbf0669b14e9ed908911a52dd6" "05c93f3395ed8b4459ec64f25c2ad41437e56f2b"]: exit status 128
fatal: remote er...
truncated to first 200 bytes; open job for full error
▶ ▼ Discussions (5)
Title Replies (including bot) Last reply
[syzbot] Monthly media report (Jun 2026) 0 (1) 2026/06/03 04:32
[PATCH v2 2/2] media: xc2028: hold the device if firmware loading is in progress 4 (4) 2025/10/14 08:11
[PATCH 2/2] media: xc2028: hold the device if firmware loading is in progress 2 (2) 2025/08/11 06:44
[syzbot] [media?] [usb?] KASAN: slab-use-after-free Read in load_firmware_cb (2) 0 (2) 2025/08/05 15:46
[syzbot] Monthly media report (Jun 2025) 0 (1) 2025/06/24 13:52
▶ ▼ Similar bugs (4)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KASAN: slab-use-after-free Read in load_firmware_cb media 19 4 668d 722d 0/29 auto-obsoleted due to no activity on 2024/12/23 23:36
upstream KASAN: use-after-free Read in load_firmware_cb usb media 19 C 12 1424d 2340d 0/29 auto-obsoleted due to no activity on 2023/11/09 13:12
linux-6.1 KASAN: use-after-free Read in load_firmware_cb 19 2 722d 723d 0/3 auto-obsoleted due to no activity on 2024/11/10 09:01
linux-6.1 KASAN: use-after-free Read in load_firmware_cb (2) origin:upstream 19 C error 10 11d 279d 0/3 upstream: reported C repro on 2025/10/18 16:24
▶ ▼ Last patch testing requests (12)
Created Duration User Patch Repo Result
2026/07/25 14:22 24m retest repro git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci report log
2026/06/16 05:29 27m retest repro git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci report log
2026/06/16 05:29 25m retest repro git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci report log
2026/06/16 05:29 6h42m retest repro git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci report log
2026/05/26 11:50 26m retest repro git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci report log
2026/05/26 11:42 23m retest repro git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci report log
2026/05/12 11:16 22m (2) retest repro git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci report log
2026/04/06 22:39 24m retest repro git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci error
2026/04/06 22:39 1h19m retest repro git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci error
2026/04/06 22:39 1h05m retest repro git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci error
2025/08/05 15:46 32m dmantipov@yandex.ru patch https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 7e161a991ea71e6ec526abc8f40c6852ebe3d946 OK log
2025/04/04 04:07 29m hdanton@sina.com patch git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci OK log

Sample crash report:
==================================================================
BUG: KASAN: slab-use-after-free in load_firmware_cb+0xbc/0x14f4 drivers/media/tuners/xc2028.c:1372
Read of size 8 at addr ffff0000c2810318 by task kworker/1:15/6916

CPU: 1 UID: 0 PID: 6916 Comm: kworker/1:15 Not tainted syzkaller #0 PREEMPT 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/03/2025
Workqueue: events request_firmware_work_func
Call trace:
 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:499 (C)
 __dump_stack+0x30/0x40 lib/dump_stack.c:94
 dump_stack_lvl+0xd8/0x12c lib/dump_stack.c:120
 print_address_description+0xa8/0x238 mm/kasan/report.c:378
 print_report+0x68/0x84 mm/kasan/report.c:482
 kasan_report+0xb0/0x110 mm/kasan/report.c:595
 __asan_report_load8_noabort+0x20/0x2c mm/kasan/report_generic.c:381
 load_firmware_cb+0xbc/0x14f4 drivers/media/tuners/xc2028.c:1372
 request_firmware_work_func+0xe8/0x19c drivers/base/firmware_loader/main.c:1161
 process_one_work+0x7e8/0x155c kernel/workqueue.c:3263
 process_scheduled_works kernel/workqueue.c:3346 [inline]
 worker_thread+0x958/0xed8 kernel/workqueue.c:3427
 kthread+0x5fc/0x75c kernel/kthread.c:463
 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:844

Allocated by task 6180:
 kasan_save_stack mm/kasan/common.c:56 [inline]
 kasan_save_track+0x40/0x78 mm/kasan/common.c:77
 kasan_save_alloc_info+0x44/0x54 mm/kasan/generic.c:573
 poison_kmalloc_redzone mm/kasan/common.c:400 [inline]
 __kasan_kmalloc+0x9c/0xb4 mm/kasan/common.c:417
 kasan_kmalloc include/linux/kasan.h:262 [inline]
 __kmalloc_cache_noprof+0x3a4/0x65c mm/slub.c:5771
 kmalloc_noprof include/linux/slab.h:957 [inline]
 syslog_print+0xf0/0x624 kernel/printk/printk.c:1580
 do_syslog+0x3e0/0x65c kernel/printk/printk.c:1758
 __do_sys_syslog kernel/printk/printk.c:1850 [inline]
 __se_sys_syslog kernel/printk/printk.c:1848 [inline]
 __arm64_sys_syslog+0x80/0x98 kernel/printk/printk.c:1848
 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
 invoke_syscall+0x98/0x254 arch/arm64/kernel/syscall.c:49
 el0_svc_common+0xe8/0x23c arch/arm64/kernel/syscall.c:132
 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151
 el0_svc+0x5c/0x254 arch/arm64/kernel/entry-common.c:724
 el0t_64_sync_handler+0x84/0x12c arch/arm64/kernel/entry-common.c:743
 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:596

Freed by task 6180:
 kasan_save_stack mm/kasan/common.c:56 [inline]
 kasan_save_track+0x40/0x78 mm/kasan/common.c:77
 __kasan_save_free_info+0x58/0x70 mm/kasan/generic.c:587
 kasan_save_free_info mm/kasan/kasan.h:406 [inline]
 poison_slab_object mm/kasan/common.c:252 [inline]
 __kasan_slab_free+0x74/0xa4 mm/kasan/common.c:284
 kasan_slab_free include/linux/kasan.h:234 [inline]
 slab_free_hook mm/slub.c:2543 [inline]
 slab_free mm/slub.c:6642 [inline]
 kfree+0x184/0x600 mm/slub.c:6849
 syslog_print+0x5bc/0x624 kernel/printk/printk.c:1672
 do_syslog+0x3e0/0x65c kernel/printk/printk.c:1758
 __do_sys_syslog kernel/printk/printk.c:1850 [inline]
 __se_sys_syslog kernel/printk/printk.c:1848 [inline]
 __arm64_sys_syslog+0x80/0x98 kernel/printk/printk.c:1848
 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
 invoke_syscall+0x98/0x254 arch/arm64/kernel/syscall.c:49
 el0_svc_common+0xe8/0x23c arch/arm64/kernel/syscall.c:132
 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151
 el0_svc+0x5c/0x254 arch/arm64/kernel/entry-common.c:724
 el0t_64_sync_handler+0x84/0x12c arch/arm64/kernel/entry-common.c:743
 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:596

The buggy address belongs to the object at ffff0000c2810000
 which belongs to the cache kmalloc-2k of size 2048
The buggy address is located 792 bytes inside of
 freed 2048-byte region [ffff0000c2810000, ffff0000c2810800)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x102810
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0x5ffc00000000040(head|node=0|zone=2|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 05ffc00000000040 ffff0000c0002000 fffffdffc3299000 dead000000000002
raw: 0000000000000000 0000000000080008 00000000f5000000 0000000000000000
head: 05ffc00000000040 ffff0000c0002000 fffffdffc3299000 dead000000000002
head: 0000000000000000 0000000000080008 00000000f5000000 0000000000000000
head: 05ffc00000000003 fffffdffc30a0401 00000000ffffffff 00000000ffffffff
head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000008
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff0000c2810200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff0000c2810280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff0000c2810300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                            ^
 ffff0000c2810380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff0000c2810400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================

Crashes (5):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/12/09 06:17 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 05c93f3395ed d6526ea3 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 KASAN: slab-use-after-free Read in load_firmware_cb
2025/06/16 02:53 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 39dfc971e42d 5f4b362d .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 KASAN: slab-use-after-free Read in load_firmware_cb
2025/03/29 07:32 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci a2392f333575 cf25e2c2 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 KASAN: slab-use-after-free Read in load_firmware_cb
2025/03/26 07:13 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci a2392f333575 89d30d73 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 KASAN: slab-use-after-free Read in load_firmware_cb
2025/09/26 13:39 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 35aa5763e111 0abd0691 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 BUG: unable to handle kernel paging request in load_firmware_cb
* Struck through repros no longer work on HEAD.