KASAN: slab-out-of-bounds Read in ec168_i2c_xfer

Status: upstream: reported C repro on 2026/03/23 20:13
Subsystems: usb media
Labels: prio:normal
[Documentation on labels]
Reported-by: syzbot+64485d3659c4c07111b4@syzkaller.appspotmail.com
First crash: 144d, last: 109d
Cause bisection: failed (error log, bisect log)
  
▶ ▼ ✨ AI Jobs (1)
ID Workflow Result Correct Bug Created Started Finished Revision
1cc2c070 assessment-security DenialOfService: ✅ Exploitable: ❌ FilesystemTrigger: ❌ NetworkTrigger: ❌ PeripheralTrigger: ❌ RemoteTrigger: ❌ Unprivileged: ❌ UserNamespace: ❌ VMGuestTrigger: ❌ VMHostTrigger: ❌ ❓ KASAN: slab-out-of-bounds Read in ec168_i2c_xfer 2026/05/21 19:25 2026/05/21 19:25 2026/05/21 20:16 d5742584
▶ ▼ Discussions (3)
Title Replies (including bot) Last reply
[PATCH v2] media: ec168: fix slab-out-of-bounds in ec168_i2c_xfer 4 (4) 2026/05/31 01:47
[PATCH] media: ec168: fix slab-out-of-bounds in ec168_i2c_xfer 1 (1) 2026/03/24 00:15
[syzbot] [media?] [usb?] KASAN: slab-out-of-bounds Read in ec168_i2c_xfer 0 (2) 2026/03/23 23:28
▶ ▼ Last patch testing requests (11)
Created Duration User Patch Repo Result
2026/07/08 06:30 28m retest repro linux-next log
2026/07/08 06:30 37m retest repro linux-next log
2026/06/22 23:24 28m retest repro linux-next log
2026/06/22 23:24 32m retest repro linux-next log
2026/06/22 23:24 40m retest repro linux-next log
2026/06/22 23:24 27m retest repro linux-next log
2026/06/21 10:05 28m retest repro linux-next log
2026/04/26 15:46 33m retest repro linux-next report log
2026/04/26 15:46 27m retest repro linux-next report log
2026/04/12 09:46 24m retest repro linux-next report log
2026/03/23 23:28 37m kartikey406@gmail.com patch linux-next OK log

Sample crash report:
==================================================================
BUG: KASAN: slab-out-of-bounds in ec168_i2c_xfer+0x4cd/0x640 drivers/media/usb/dvb-usb-v2/ec168.c:143
Read of size 1 at addr ffff8880216b9381 by task syz.0.17/6015

CPU: 1 UID: 0 PID: 6015 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 print_address_description+0x55/0x1e0 mm/kasan/report.c:378
 print_report+0x58/0x70 mm/kasan/report.c:482
 kasan_report+0x117/0x150 mm/kasan/report.c:595
 ec168_i2c_xfer+0x4cd/0x640 drivers/media/usb/dvb-usb-v2/ec168.c:143
 __i2c_transfer+0x79a/0x1f70 drivers/i2c/i2c-core-base.c:-1
 i2c_transfer+0x1cc/0x2d0 drivers/i2c/i2c-core-base.c:2317
 i2cdev_ioctl_rdwr+0x460/0x740 drivers/i2c/i2c-dev.c:306
 i2cdev_ioctl+0x6a5/0x880 drivers/i2c/i2c-dev.c:467
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:597 [inline]
 __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f43a7f9c799
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffc17587fc8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f43a8215fa0 RCX: 00007f43a7f9c799
RDX: 0000200000000140 RSI: 0000000000000707 RDI: 0000000000000004
RBP: 00007f43a8032c99 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f43a8215fac R14: 00007f43a8215fa0 R15: 00007f43a8215fa0
 </TASK>

Allocated by task 6015:
 kasan_save_stack mm/kasan/common.c:57 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
 poison_kmalloc_redzone mm/kasan/common.c:398 [inline]
 __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:415
 kasan_kmalloc include/linux/kasan.h:263 [inline]
 __do_kmalloc_node mm/slub.c:5292 [inline]
 __kmalloc_node_track_caller_noprof+0x4db/0x7b0 mm/slub.c:5400
 memdup_user+0x2b/0xd0 mm/util.c:221
 i2cdev_ioctl_rdwr+0x1c6/0x740 drivers/i2c/i2c-dev.c:266
 i2cdev_ioctl+0x6a5/0x880 drivers/i2c/i2c-dev.c:467
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:597 [inline]
 __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff8880216b9380
 which belongs to the cache kmalloc-8 of size 8
The buggy address is located 0 bytes to the right of
 allocated 1-byte region [ffff8880216b9380, ffff8880216b9381)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff8880216b91e0 pfn:0x216b9
flags: 0xfff00000000200(workingset|node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000200 ffff88813fe32500 ffff88813fe31348 ffffea000087ba90
raw: ffff8880216b91e0 000000080080007b 00000000f5000000 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0xd2cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 1, tgid 1 (swapper/0), ts 3279848024, free_ts 3222224875
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x231/0x280 mm/page_alloc.c:1859
 prep_new_page mm/page_alloc.c:1867 [inline]
 get_page_from_freelist+0x2418/0x24b0 mm/page_alloc.c:3926
 __alloc_frozen_pages_noprof+0x233/0x3d0 mm/page_alloc.c:5213
 alloc_slab_page mm/slub.c:3278 [inline]
 allocate_slab+0x77/0x660 mm/slub.c:3467
 new_slab mm/slub.c:3525 [inline]
 refill_objects+0x339/0x3d0 mm/slub.c:7247
 refill_sheaf mm/slub.c:2816 [inline]
 __pcs_replace_empty_main+0x321/0x720 mm/slub.c:4651
 alloc_from_pcs mm/slub.c:4749 [inline]
 slab_alloc_node mm/slub.c:4883 [inline]
 __do_kmalloc_node mm/slub.c:5291 [inline]
 __kmalloc_noprof+0x474/0x760 mm/slub.c:5304
 kmalloc_noprof include/linux/slab.h:954 [inline]
 kzalloc_noprof include/linux/slab.h:1188 [inline]
 acpi_ns_internalize_name+0x2c9/0x3e0 drivers/acpi/acpica/nsutils.c:331
 acpi_ns_get_node_unlocked+0x186/0x480 drivers/acpi/acpica/nsutils.c:666
 acpi_ns_get_node+0x76/0xc0 drivers/acpi/acpica/nsutils.c:726
 acpi_ns_evaluate+0x283/0x1230 drivers/acpi/acpica/nseval.c:62
 acpi_ut_evaluate_object+0xe1/0x560 drivers/acpi/acpica/uteval.c:60
 acpi_ut_execute_CID+0xc6/0x710 drivers/acpi/acpica/utids.c:214
 acpi_ns_get_device_callback+0x2bc/0x4c0 drivers/acpi/acpica/nsxfeval.c:694
 acpi_ns_walk_namespace+0x2a7/0x770 drivers/acpi/acpica/nswalk.c:-1
 acpi_get_devices+0x14b/0x1e0 drivers/acpi/acpica/nsxfeval.c:805
page last free pid 1 tgid 1 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 __free_pages_prepare mm/page_alloc.c:1403 [inline]
 __free_frozen_pages+0xbc7/0xd30 mm/page_alloc.c:2944
 __slab_free+0x274/0x2c0 mm/slub.c:5605
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x99/0x100 mm/kasan/quarantine.c:179
 kasan_quarantine_remove_cache+0x342/0x360 mm/kasan/quarantine.c:378
 kmem_cache_shrink+0xd/0x20 mm/slab_common.c:604
 acpi_os_purge_cache+0x15/0x20 drivers/acpi/osl.c:1622
 acpi_purge_cached_objects+0xd5/0x100 drivers/acpi/acpica/utxface.c:240
 acpi_initialize_objects+0x2e/0xb0 drivers/acpi/acpica/utxfinit.c:250
 acpi_bus_init+0xa8/0x360 drivers/acpi/bus.c:1421
 acpi_init+0xa1/0x1f0 drivers/acpi/bus.c:1510
 do_one_initcall+0x250/0x870 init/main.c:1384
 do_initcall_level+0x104/0x190 init/main.c:1446
 do_initcalls+0x59/0xa0 init/main.c:1462
 kernel_init_freeable+0x2a6/0x3e0 init/main.c:1694
 kernel_init+0x1d/0x1d0 init/main.c:1584
 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158

Memory state around the buggy address:
 ffff8880216b9280: 00 fc fc fc 00 fc fc fc 00 fc fc fc 00 fc fc fc
 ffff8880216b9300: 00 fc fc fc 00 fc fc fc 00 fc fc fc fa fc fc fc
>ffff8880216b9380: 01 fc fc fc 00 fc fc fc fa fc fc fc fa fc fc fc
                   ^
 ffff8880216b9400: fa fc fc fc fa fc fc fc 00 fc fc fc fa fc fc fc
 ffff8880216b9480: fa fc fc fc fa fc fc fc fa fc fc fc fa fc fc fc
==================================================================

Crashes (9):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/03/24 12:03 linux-next 09c0f7f1bcdb baf8bf12 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-rust-kasan-gce KASAN: slab-out-of-bounds Read in ec168_i2c_xfer
2026/03/24 10:26 linux-next 09c0f7f1bcdb baf8bf12 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-rust-kasan-gce KASAN: slab-out-of-bounds Read in ec168_i2c_xfer
2026/03/22 11:14 linux-next 785f0eb2f85d 5b92003d .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root KASAN: slab-out-of-bounds Read in ec168_i2c_xfer
2026/03/22 09:47 linux-next 785f0eb2f85d 5b92003d .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root KASAN: slab-out-of-bounds Read in ec168_i2c_xfer
2026/03/22 07:47 linux-next 785f0eb2f85d 5b92003d .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root KASAN: slab-out-of-bounds Read in ec168_i2c_xfer
2026/03/22 05:59 linux-next 785f0eb2f85d 5b92003d .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root KASAN: slab-out-of-bounds Read in ec168_i2c_xfer
2026/03/22 04:30 linux-next 785f0eb2f85d 5b92003d .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root KASAN: slab-out-of-bounds Read in ec168_i2c_xfer
2026/03/29 08:46 upstream cbfffcca2bf0 356bdfc9 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce KASAN: slab-out-of-bounds Read in ec168_i2c_xfer
2026/03/22 03:05 linux-next 785f0eb2f85d 5b92003d .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root KASAN: slab-out-of-bounds Read in ec168_i2c_xfer
* Struck through repros no longer work on HEAD.