* [syzbot] [input?] KASAN: stack-out-of-bounds Read in ft260_smbus_write
@ 2026-01-20 2:52 syzbot
2026-01-20 5:42 ` Jeongjun Park
` (2 more replies)
0 siblings, 3 replies; 6+ messages in thread
From: syzbot @ 2026-01-20 2:52 UTC (permalink / raw)
To: bentiss, jikos, linux-i2c, linux-input, linux-kernel,
michael.zaidman, syzkaller-bugs
Hello,
syzbot found the following issue on:
HEAD commit: 603c05a1639f Merge tag 'nfs-for-6.19-2' of git://git.linux..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=120d339a580000
kernel config: https://syzkaller.appspot.com/x/.config?x=1859476832863c41
dashboard link: https://syzkaller.appspot.com/bug?extid=64ca69977b37604cd6d9
compiler: gcc (Debian 12.2.0-14+deb12u1) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=161e0852580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=13115522580000
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/b694f12a8d6f/disk-603c05a1.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/91efc898c41a/vmlinux-603c05a1.xz
kernel image: https://storage.googleapis.com/syzbot-assets/d0cbdf66f29d/bzImage-603c05a1.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+64ca69977b37604cd6d9@syzkaller.appspotmail.com
==================================================================
BUG: KASAN: stack-out-of-bounds in ft260_smbus_write+0x19b/0x2f0 drivers/hid/hid-ft260.c:486
Read of size 42 at addr ffffc90003427d81 by task syz.2.65/6119
CPU: 0 UID: 0 PID: 6119 Comm: syz.2.65 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
print_address_description mm/kasan/report.c:378 [inline]
print_report+0xcd/0x630 mm/kasan/report.c:482
kasan_report+0xe0/0x110 mm/kasan/report.c:595
check_region_inline mm/kasan/generic.c:194 [inline]
kasan_check_range+0x100/0x1b0 mm/kasan/generic.c:200
__asan_memcpy+0x23/0x60 mm/kasan/shadow.c:105
ft260_smbus_write+0x19b/0x2f0 drivers/hid/hid-ft260.c:486
ft260_smbus_xfer+0x22c/0x640 drivers/hid/hid-ft260.c:736
__i2c_smbus_xfer drivers/i2c/i2c-core-smbus.c:591 [inline]
__i2c_smbus_xfer+0x4f0/0xf60 drivers/i2c/i2c-core-smbus.c:554
i2c_smbus_xfer drivers/i2c/i2c-core-smbus.c:546 [inline]
i2c_smbus_xfer+0x200/0x3c0 drivers/i2c/i2c-core-smbus.c:536
i2cdev_ioctl_smbus+0x237/0x990 drivers/i2c/i2c-dev.c:389
i2cdev_ioctl+0x361/0x840 drivers/i2c/i2c-dev.c:478
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:597 [inline]
__se_sys_ioctl fs/ioctl.c:583 [inline]
__x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f88dd98f749
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:00007ffeebbe43a8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f88ddbe5fa0 RCX: 00007f88dd98f749
RDX: 0000200000000200 RSI: 0000000000000720 RDI: 0000000000000004
RBP: 00007f88dda13f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f88ddbe5fa0 R14: 00007f88ddbe5fa0 R15: 0000000000000003
</TASK>
The buggy address belongs to stack of task syz.2.65/6119
and is located at offset 49 in frame:
i2cdev_ioctl_smbus+0x0/0x990 drivers/i2c/i2c-dev.c:632
This frame has 1 object:
[48, 82) 'temp'
The buggy address belongs to a 8-page vmalloc region starting at 0xffffc90003420000 allocated at kernel_clone+0xfc/0x910 kernel/fork.c:2651
The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x22397
memcg:ffff888074f11282
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000000 0000000000000000 ffffea000088e5c8 0000000000000000
raw: 0000000000000000 0000000000000000 00000001ffffffff ffff888074f11282
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x29c2(GFP_NOWAIT|__GFP_HIGHMEM|__GFP_IO|__GFP_FS|__GFP_ZERO), pid 5928, tgid 5928 (syz-executor), ts 80598654650, free_ts 80595057505
set_page_owner include/linux/page_owner.h:32 [inline]
post_alloc_hook+0x1af/0x220 mm/page_alloc.c:1884
prep_new_page mm/page_alloc.c:1892 [inline]
get_page_from_freelist+0xd0b/0x31a0 mm/page_alloc.c:3945
__alloc_frozen_pages_noprof+0x25f/0x2430 mm/page_alloc.c:5240
alloc_pages_mpol+0x1fb/0x550 mm/mempolicy.c:2486
alloc_frozen_pages_noprof mm/mempolicy.c:2557 [inline]
alloc_pages_noprof+0x131/0x390 mm/mempolicy.c:2577
vm_area_alloc_pages mm/vmalloc.c:3649 [inline]
__vmalloc_area_node mm/vmalloc.c:3863 [inline]
__vmalloc_node_range_noprof+0xe6c/0x16b0 mm/vmalloc.c:4051
__vmalloc_node_noprof+0xad/0xf0 mm/vmalloc.c:4111
alloc_thread_stack_node kernel/fork.c:354 [inline]
dup_task_struct kernel/fork.c:923 [inline]
copy_process+0x619/0x7430 kernel/fork.c:2052
kernel_clone+0xfc/0x910 kernel/fork.c:2651
__do_sys_clone+0xce/0x120 kernel/fork.c:2792
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
page last free pid 5928 tgid 5928 stack trace:
reset_page_owner include/linux/page_owner.h:25 [inline]
free_pages_prepare mm/page_alloc.c:1433 [inline]
__free_frozen_pages+0x7df/0x1170 mm/page_alloc.c:2973
discard_slab mm/slub.c:3346 [inline]
__put_partials+0x130/0x170 mm/slub.c:3886
qlink_free mm/kasan/quarantine.c:163 [inline]
qlist_free_all+0x4c/0xf0 mm/kasan/quarantine.c:179
kasan_quarantine_reduce+0x195/0x1e0 mm/kasan/quarantine.c:286
__kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:350
kasan_slab_alloc include/linux/kasan.h:253 [inline]
slab_post_alloc_hook mm/slub.c:4953 [inline]
slab_alloc_node mm/slub.c:5263 [inline]
__kmalloc_cache_node_noprof+0x299/0x830 mm/slub.c:5784
kmalloc_node_noprof include/linux/slab.h:983 [inline]
__get_vm_area_node+0x101/0x330 mm/vmalloc.c:3208
__vmalloc_node_range_noprof+0x247/0x16b0 mm/vmalloc.c:4011
__vmalloc_node_noprof+0xad/0xf0 mm/vmalloc.c:4111
xt_counters_alloc+0x4c/0x70 net/netfilter/x_tables.c:1381
__do_replace+0x97/0x9e0 net/ipv4/netfilter/ip_tables.c:1046
do_replace net/ipv4/netfilter/ip_tables.c:1141 [inline]
do_ipt_set_ctl+0x93b/0xc40 net/ipv4/netfilter/ip_tables.c:1635
nf_setsockopt+0x8d/0xf0 net/netfilter/nf_sockopt.c:101
ip_setsockopt+0xcb/0xf0 net/ipv4/ip_sockglue.c:1424
tcp_setsockopt+0xa7/0x100 net/ipv4/tcp.c:4164
do_sock_setsockopt+0xf3/0x1d0 net/socket.c:2322
Memory state around the buggy address:
ffffc90003427c80: f3 f3 f3 00 00 00 00 00 00 00 00 00 00 00 00 00
ffffc90003427d00: 00 00 00 00 00 00 00 00 00 00 f1 f1 f1 f1 f1 f1
>ffffc90003427d80: 00 00 00 00 02 f3 f3 f3 f3 f3 00 00 00 00 00 00
^
ffffc90003427e00: 00 00 00 00 00 00 f1 f1 f1 f1 f1 f1 04 f2 00 00
ffffc90003427e80: f3 f3 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================
---
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
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [syzbot] [input?] KASAN: stack-out-of-bounds Read in ft260_smbus_write
2026-01-20 2:52 [syzbot] [input?] KASAN: stack-out-of-bounds Read in ft260_smbus_write syzbot
@ 2026-01-20 5:42 ` Jeongjun Park
2026-01-20 6:38 ` syzbot
2026-01-20 13:30 ` Edward Adam Davis
2026-01-20 13:47 ` [PATCH] i2c: add sanity check for input SMBus data length Edward Adam Davis
2 siblings, 1 reply; 6+ messages in thread
From: Jeongjun Park @ 2026-01-20 5:42 UTC (permalink / raw)
To: syzbot+64ca69977b37604cd6d9; +Cc: linux-kernel, syzkaller-bugs
#syz test upstream master
---
drivers/hid/hid-ft260.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/hid/hid-ft260.c b/drivers/hid/hid-ft260.c
index 333341e80b0e..acfd69ed71a0 100644
--- a/drivers/hid/hid-ft260.c
+++ b/drivers/hid/hid-ft260.c
@@ -471,7 +471,8 @@ static int ft260_smbus_write(struct ft260_device *dev, u8 addr, u8 cmd,
struct ft260_i2c_write_request_report *rep =
(struct ft260_i2c_write_request_report *)dev->write_buf;
- if (data_len >= sizeof(rep->data))
+ if (data_len >= sizeof(rep->data) ||
+ data_len >= sizeof(data))
return -EINVAL;
rep->address = addr;
--
^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [syzbot] [input?] KASAN: stack-out-of-bounds Read in ft260_smbus_write
2026-01-20 5:42 ` Jeongjun Park
@ 2026-01-20 6:38 ` syzbot
0 siblings, 0 replies; 6+ messages in thread
From: syzbot @ 2026-01-20 6:38 UTC (permalink / raw)
To: aha310510, linux-kernel, syzkaller-bugs
Hello,
syzbot has tested the proposed patch and the reproducer did not trigger any issue:
Reported-by: syzbot+64ca69977b37604cd6d9@syzkaller.appspotmail.com
Tested-by: syzbot+64ca69977b37604cd6d9@syzkaller.appspotmail.com
Tested on:
commit: 24d479d2 Linux 6.19-rc6
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=13724d22580000
kernel config: https://syzkaller.appspot.com/x/.config?x=1859476832863c41
dashboard link: https://syzkaller.appspot.com/bug?extid=64ca69977b37604cd6d9
compiler: gcc (Debian 12.2.0-14+deb12u1) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
patch: https://syzkaller.appspot.com/x/patch.diff?x=16de33fa580000
Note: testing is done by a robot and is best-effort only.
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [syzbot] [input?] KASAN: stack-out-of-bounds Read in ft260_smbus_write
2026-01-20 2:52 [syzbot] [input?] KASAN: stack-out-of-bounds Read in ft260_smbus_write syzbot
2026-01-20 5:42 ` Jeongjun Park
@ 2026-01-20 13:30 ` Edward Adam Davis
2026-01-20 13:32 ` syzbot
2026-01-20 13:47 ` [PATCH] i2c: add sanity check for input SMBus data length Edward Adam Davis
2 siblings, 1 reply; 6+ messages in thread
From: Edward Adam Davis @ 2026-01-20 13:30 UTC (permalink / raw)
To: syzbot+64ca69977b37604cd6d9; +Cc: linux-kernel, syzkaller-bugs
#syz test
diff --git a/drivers/i2c/i2c-dev.c b/drivers/i2c/i2c-dev.c
index e9577f920286..6725a49d6921 100644
--- a/drivers/i2c/i2c-dev.c
+++ b/drivers/i2c/i2c-dev.c
@@ -378,6 +378,14 @@ static noinline int i2cdev_ioctl_smbus(struct i2c_client *client,
(read_write == I2C_SMBUS_WRITE)) {
if (copy_from_user(&temp, data, datasize))
return -EFAULT;
+
+ if (temp.block[0] > datasize) {
+ dev_dbg(&client->adapter->dev,
+ "user input data size (%u) is too big "
+ "in ioctl I2C_SMBUS.\n",
+ temp.block[0]);
+ return -EINVAL;
+ }
}
if (size == I2C_SMBUS_I2C_BLOCK_BROKEN) {
/* Convert old I2C block commands to the new
^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [syzbot] [input?] KASAN: stack-out-of-bounds Read in ft260_smbus_write
2026-01-20 13:30 ` Edward Adam Davis
@ 2026-01-20 13:32 ` syzbot
0 siblings, 0 replies; 6+ messages in thread
From: syzbot @ 2026-01-20 13:32 UTC (permalink / raw)
To: eadavis, linux-kernel, syzkaller-bugs
Hello,
syzbot tried to test the proposed patch but the build/boot failed:
failed to checkout kernel repo git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/master: failed to run ["git" "checkout" "FETCH_HEAD" "--force"]: exit status 128
Tested on:
commit: [unknown
git tree: upstream
kernel config: https://syzkaller.appspot.com/x/.config?x=1859476832863c41
dashboard link: https://syzkaller.appspot.com/bug?extid=64ca69977b37604cd6d9
compiler:
patch: https://syzkaller.appspot.com/x/patch.diff?x=10af33fa580000
^ permalink raw reply [flat|nested] 6+ messages in thread
* [PATCH] i2c: add sanity check for input SMBus data length
2026-01-20 2:52 [syzbot] [input?] KASAN: stack-out-of-bounds Read in ft260_smbus_write syzbot
2026-01-20 5:42 ` Jeongjun Park
2026-01-20 13:30 ` Edward Adam Davis
@ 2026-01-20 13:47 ` Edward Adam Davis
2 siblings, 0 replies; 6+ messages in thread
From: Edward Adam Davis @ 2026-01-20 13:47 UTC (permalink / raw)
To: syzbot+64ca69977b37604cd6d9
Cc: bentiss, jikos, linux-i2c, linux-input, linux-kernel,
michael.zaidman, syzkaller-bugs
The value passed to block[0] in the user-constructed data is too large,
exceeding the length that data for SMBus messages can accommodate. This
triggered the out-of-bounds access reported by syzbot [1].
Adding relevant data size checks in the smbus ioctl can prevent this
out-of-bounds access.
[1]
BUG: KASAN: stack-out-of-bounds in ft260_smbus_write+0x19b/0x2f0 drivers/hid/hid-ft260.c:486
Read of size 42 at addr ffffc90003427d81 by task syz.2.65/6119
Call Trace:
ft260_smbus_write+0x19b/0x2f0 drivers/hid/hid-ft260.c:486
ft260_smbus_xfer+0x22c/0x640 drivers/hid/hid-ft260.c:736
Reported-by: syzbot+64ca69977b37604cd6d9@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=64ca69977b37604cd6d9
Signed-off-by: Edward Adam Davis <eadavis@qq.com>
---
drivers/i2c/i2c-dev.c | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/drivers/i2c/i2c-dev.c b/drivers/i2c/i2c-dev.c
index e9577f920286..6725a49d6921 100644
--- a/drivers/i2c/i2c-dev.c
+++ b/drivers/i2c/i2c-dev.c
@@ -378,6 +378,14 @@ static noinline int i2cdev_ioctl_smbus(struct i2c_client *client,
(read_write == I2C_SMBUS_WRITE)) {
if (copy_from_user(&temp, data, datasize))
return -EFAULT;
+
+ if (temp.block[0] > datasize) {
+ dev_dbg(&client->adapter->dev,
+ "user input data size (%u) is too big "
+ "in ioctl I2C_SMBUS.\n",
+ temp.block[0]);
+ return -EINVAL;
+ }
}
if (size == I2C_SMBUS_I2C_BLOCK_BROKEN) {
/* Convert old I2C block commands to the new
--
2.43.0
^ permalink raw reply related [flat|nested] 6+ messages in thread
end of thread, other threads:[~2026-01-20 13:47 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
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2026-01-20 2:52 [syzbot] [input?] KASAN: stack-out-of-bounds Read in ft260_smbus_write syzbot
2026-01-20 5:42 ` Jeongjun Park
2026-01-20 6:38 ` syzbot
2026-01-20 13:30 ` Edward Adam Davis
2026-01-20 13:32 ` syzbot
2026-01-20 13:47 ` [PATCH] i2c: add sanity check for input SMBus data length Edward Adam Davis
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