[v6.6] WARNING in dtv5100_i2c_msg

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 5fa4793a2d2d Linux 6.6.119
git tree: linux-6.6.y
console output: https://syzkaller.appspot.com/x/log.txt?x=1214dd92580000
kernel config: https://syzkaller.appspot.com/x/.config?x=691a6769a86ac817
dashboard link: https://syzkaller.appspot.com/bug?extid=f8c9e695a23d119e23ff
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/63699875f1dd/disk-5fa4793a.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/8506652fcb6f/vmlinux-5fa4793a.xz
kernel image: https://storage.googleapis.com/syzbot-assets/1b30ceed1710/bzImage-5fa4793a.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+f8c9e6...@syzkaller.appspotmail.com

memcpy: detected field-spanning write (size 83) of single field "st->data" at drivers/media/usb/dvb-usb/dtv5100.c:58 (size 80)
WARNING: CPU: 0 PID: 11165 at drivers/media/usb/dvb-usb/dtv5100.c:58 dtv5100_i2c_msg+0x2a5/0x320 drivers/media/usb/dvb-usb/dtv5100.c:58
Modules linked in:
CPU: 0 PID: 11165 Comm: syz.2.963 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:dtv5100_i2c_msg+0x2a5/0x320 drivers/media/usb/dvb-usb/dtv5100.c:58
Code: 20 eb d6 e8 9d 39 80 fa c6 05 07 73 2f 07 01 b9 50 00 00 00 48 c7 c7 e0 12 6b 8b 4c 89 e6 48 c7 c2 60 13 6b 8b e8 ab b5 4a fa <0f> 0b e9 3d ff ff ff 44 89 e9 80 e1 07 38 c1 0f 8c eb fe ff ff 4c
RSP: 0018:ffffc9000c4afaa0 EFLAGS: 00010246
RAX: 0c8a06b88bbabb00 RBX: ffff88807ec90000 RCX: 0000000000080000
RDX: ffffc9000d31c000 RSI: 000000000001c93b RDI: 000000000001c93c
RBP: 0000000000000202 R08: ffffc9000c4af6a7 R09: 1ffff92001895ed4
R10: dffffc0000000000 R11: fffff52001895ed5 R12: 0000000000000053
R13: ffff888064d58780 R14: 00000000000000c7 R15: 0000000080001100
FS: 00007ff2d56aa6c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fcb86fd027c CR3: 0000000021f1e000 CR4: 00000000003506f0
Call Trace:
<TASK>
dtv5100_i2c_xfer+0x269/0x3b0 drivers/media/usb/dvb-usb/dtv5100.c:81
__i2c_transfer+0x868/0x2080 drivers/i2c/i2c-core-base.c:-1
i2c_transfer+0x250/0x390 drivers/i2c/i2c-core-base.c:2328
i2cdev_ioctl_rdwr+0x3b0/0x690 drivers/i2c/i2c-dev.c:297
i2cdev_ioctl+0x646/0x7e0 drivers/i2c/i2c-dev.c:458
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:871 [inline]
__se_sys_ioctl+0xfd/0x170 fs/ioctl.c:857
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7ff2d478f749
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ff2d56aa038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007ff2d49e5fa0 RCX: 00007ff2d478f749
RDX: 00002000000002c0 RSI: 0000000000000707 RDI: 0000000000000004
RBP: 00007ff2d4813f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ff2d49e6038 R14: 00007ff2d49e5fa0 R15: 00007ffd578ac0e8
</TASK>


---
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[syzbot]

syzbot has found a reproducer for the following issue on:

HEAD commit: 5fa4793a2d2d Linux 6.6.119
git tree: linux-6.6.y

console output: https://syzkaller.appspot.com/x/log.txt?x=16aa331a580000

kernel config: https://syzkaller.appspot.com/x/.config?x=691a6769a86ac817
dashboard link: https://syzkaller.appspot.com/bug?extid=f8c9e695a23d119e23ff
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8

syz repro: https://syzkaller.appspot.com/x/repro.syz?x=112cdd92580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1155b9b4580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/63699875f1dd/disk-5fa4793a.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/8506652fcb6f/vmlinux-5fa4793a.xz
kernel image: https://storage.googleapis.com/syzbot-assets/1b30ceed1710/bzImage-5fa4793a.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+f8c9e6...@syzkaller.appspotmail.com

memcpy: detected field-spanning write (size 83) of single field "st->data" at drivers/media/usb/dvb-usb/dtv5100.c:58 (size 80)

WARNING: CPU: 1 PID: 5929 at drivers/media/usb/dvb-usb/dtv5100.c:58 dtv5100_i2c_msg+0x2a5/0x320 drivers/media/usb/dvb-usb/dtv5100.c:58
Modules linked in:
CPU: 1 PID: 5929 Comm: syz.0.17 Not tainted syzkaller #0

Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:dtv5100_i2c_msg+0x2a5/0x320 drivers/media/usb/dvb-usb/dtv5100.c:58
Code: 20 eb d6 e8 9d 39 80 fa c6 05 07 73 2f 07 01 b9 50 00 00 00 48 c7 c7 e0 12 6b 8b 4c 89 e6 48 c7 c2 60 13 6b 8b e8 ab b5 4a fa <0f> 0b e9 3d ff ff ff 44 89 e9 80 e1 07 38 c1 0f 8c eb fe ff ff 4c

RSP: 0018:ffffc9000453faa0 EFLAGS: 00010246
RAX: c1d9da64e712ac00 RBX: ffff88807d6c4000 RCX: ffff88802a9c5a00
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000002
RBP: 0000000000000202 R08: ffffffff90d945ff R09: 1ffffffff21b28bf
R10: dffffc0000000000 R11: fffffbfff21b28c0 R12: 0000000000000053
R13: ffff8880741d0500 R14: 00000000000000c7 R15: 0000000080000200
FS: 0000555593e5c500(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000

CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033

CR2: 00007fffb28eac80 CR3: 00000000754a5000 CR4: 00000000003506e0

Call Trace:
<TASK>
dtv5100_i2c_xfer+0x269/0x3b0 drivers/media/usb/dvb-usb/dtv5100.c:81
__i2c_transfer+0x868/0x2080 drivers/i2c/i2c-core-base.c:-1
i2c_transfer+0x250/0x390 drivers/i2c/i2c-core-base.c:2328
i2cdev_ioctl_rdwr+0x3b0/0x690 drivers/i2c/i2c-dev.c:297
i2cdev_ioctl+0x646/0x7e0 drivers/i2c/i2c-dev.c:458
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:871 [inline]
__se_sys_ioctl+0xfd/0x170 fs/ioctl.c:857
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2

RIP: 0033:0x7f496cd8f749

Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48

RSP: 002b:00007ffd5c64a2c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f496cfe5fa0 RCX: 00007f496cd8f749

RDX: 00002000000002c0 RSI: 0000000000000707 RDI: 0000000000000004

RBP: 00007f496ce13f91 R08: 0000000000000000 R09: 0000000000000000

R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000

R13: 00007f496cfe5fa0 R14: 00007f496cfe5fa0 R15: 0000000000000003
</TASK>


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