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

Status: upstream: reported C repro on 2026/09/06 22:26
Reported-by: syzbot+697cf494e5152235d4df@syzkaller.appspotmail.com
First crash: 28d, last: 7d00h
▶ ▼ Similar bugs (2)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KASAN: slab-out-of-bounds Read in ec168_i2c_xfer prio:normal usb media 17 syz, C error 30 14d 195d 0/29 upstream: reported C repro on 2026/03/23 20:13
linux-6.6 KASAN: slab-out-of-bounds Read in ec168_i2c_xfer 17 syz, C 5 28d 28d 0/2 upstream: reported C repro on 2026/09/06 18:09
▶ ▼ Last patch testing requests (1)
Created Duration User Patch Repo Result
2026/09/27 23:30 13m retest repro linux-5.15.y report job log log

Sample crash report:
==================================================================
BUG: KASAN: slab-out-of-bounds in ec168_i2c_xfer+0x4d1/0x630 drivers/media/usb/dvb-usb-v2/ec168.c:143
Read of size 1 at addr ffff888017b97b91 by task syz.0.17/4333

CPU: 0 PID: 4333 Comm: syz.0.17 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106
 print_address_description+0x60/0x2d0 mm/kasan/report.c:248
 __kasan_report mm/kasan/report.c:434 [inline]
 kasan_report+0xdf/0x130 mm/kasan/report.c:451
 ec168_i2c_xfer+0x4d1/0x630 drivers/media/usb/dvb-usb-v2/ec168.c:143
 __i2c_transfer+0x88d/0x2090 drivers/i2c/i2c-core-base.c:-1
 i2c_transfer+0x25d/0x3a0 drivers/i2c/i2c-core-base.c:2357
 i2cdev_ioctl_rdwr+0x3dc/0x6c0 drivers/i2c/i2c-dev.c:297
 i2cdev_ioctl+0x610/0x7b0 drivers/i2c/i2c-dev.c:458
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:874 [inline]
 __se_sys_ioctl+0xfa/0x170 fs/ioctl.c:860
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f2e97d58159
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:00007ffe5903b9a8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f2e97fdffa0 RCX: 00007f2e97d58159
RDX: 0000200000000200 RSI: 0000000000000707 RDI: 0000000000000004
RBP: 00007f2e97def024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f2e97fdffac R14: 00007f2e97fdffa0 R15: 00007f2e97fdffa0
 </TASK>

Allocated by task 4333:
 kasan_save_stack mm/kasan/common.c:38 [inline]
 kasan_set_track mm/kasan/common.c:46 [inline]
 set_alloc_info mm/kasan/common.c:434 [inline]
 ____kasan_kmalloc mm/kasan/common.c:513 [inline]
 __kasan_kmalloc+0xaf/0xe0 mm/kasan/common.c:522
 memdup_user+0x22/0xb0 mm/util.c:173
 i2cdev_ioctl_rdwr+0x140/0x6c0 drivers/i2c/i2c-dev.c:256
 i2cdev_ioctl+0x610/0x7b0 drivers/i2c/i2c-dev.c:458
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:874 [inline]
 __se_sys_ioctl+0xfa/0x170 fs/ioctl.c:860
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0

The buggy address belongs to the object at ffff888017b97b90
 which belongs to the cache kmalloc-8 of size 8
The buggy address is located 1 bytes inside of
 8-byte region [ffff888017b97b90, ffff888017b97b98)
The buggy address belongs to the page:
page:ffffea00005ee5c0 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff888017b97fc8 pfn:0x17b97
flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000200 ffffea000089ec00 0000000200000002 ffff888016c41280
raw: ffff888017b97fc8 0000000080660062 00000001ffffffff 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 0x12cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY), pid 1, ts 2549315339, free_ts 0
 prep_new_page mm/page_alloc.c:2426 [inline]
 get_page_from_freelist+0x24f6/0x2670 mm/page_alloc.c:4192
 __alloc_pages+0x1ee/0x480 mm/page_alloc.c:5501
 alloc_page_interleave+0x24/0x1e0 mm/mempolicy.c:2031
 alloc_slab_page mm/slub.c:1780 [inline]
 allocate_slab mm/slub.c:1917 [inline]
 new_slab+0xc0/0x4b0 mm/slub.c:1980
 ___slab_alloc+0x807/0xdd0 mm/slub.c:3013
 __slab_alloc mm/slub.c:3100 [inline]
 slab_alloc_node mm/slub.c:3191 [inline]
 slab_alloc mm/slub.c:3233 [inline]
 __kmalloc+0x11d/0x340 mm/slub.c:4408
 kmalloc include/linux/slab.h:612 [inline]
 kzalloc include/linux/slab.h:738 [inline]
 acpi_os_allocate_zeroed include/acpi/platform/aclinuxex.h:57 [inline]
 acpi_ns_internalize_name+0x2cd/0x3b0 drivers/acpi/acpica/nsutils.c:331
 acpi_ns_get_node_unlocked drivers/acpi/acpica/nsutils.c:666 [inline]
 acpi_ns_get_node+0x1a7/0x360 drivers/acpi/acpica/nsutils.c:726
 acpi_get_handle+0x184/0x290 drivers/acpi/acpica/nsxfname.c:98
 acpi_evaluate_object_typed+0xcc/0x380 drivers/acpi/acpica/nsxfeval.c:71
 acpi_init_properties+0x20c/0xbc0 drivers/acpi/property.c:408
 acpi_init_device_object+0x1ebc/0x2820 drivers/acpi/scan.c:1749
 acpi_add_single_object+0xed/0x1970 drivers/acpi/scan.c:1794
 acpi_bus_check_add+0x363/0x800 drivers/acpi/scan.c:2053
 acpi_ns_walk_namespace+0x21f/0x6a0 drivers/acpi/acpica/nswalk.c:-1
 acpi_walk_namespace+0xe4/0x120 drivers/acpi/acpica/nsxfeval.c:606
page_owner free stack trace missing

Memory state around the buggy address:
 ffff888017b97a80: fc fc fc fc 00 fc fc fc fc 00 fc fc fc fc 00 fc
 ffff888017b97b00: fc fc fc fa fc fc fc fc 00 fc fc fc fc 00 fc fc
>ffff888017b97b80: fc fc 01 fc fc fc fc 00 fc fc fc fc 00 fc fc fc
                         ^
 ffff888017b97c00: fc 02 fc fc fc fc fa fc fc fc fc 00 fc fc fc fc
 ffff888017b97c80: 00 fc fc fc fc 00 fc fc fc fc 00 fc fc fc fc fa
==================================================================

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/09/06 23:47 linux-5.15.y 0996e0926f6b 4f7b22a0 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: slab-out-of-bounds Read in ec168_i2c_xfer
2026/09/06 22:25 linux-5.15.y 0996e0926f6b 4f7b22a0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: slab-out-of-bounds Read in ec168_i2c_xfer
* Struck through repros no longer work on HEAD.