High · published September 18, 2025
In the Linux kernel, the following vulnerability has been resolved:
i2c: ismt: Fix an out-of-bounds bug in ismt_access()
When the driver does not check the data from the user, the variable
'data->block[0]' may be very large to cause an out-of-bounds bug.
The following log can reveal it:
[ 33.995542] i2c i2c-1: ioctl, cmd=0x720, arg=0x7ffcb3dc3a20
[ 33.995978] ismt_smbus 0000:00:05.0: I2C_SMBUS_BLOCK_DATA: WRITE
[ 33.996475] ==================================================================
[ 33.996995] BUG: KASAN: out-of-bounds in ismt_access.cold+0x374/0x214b
[ 33.997473] Read of size 18446744073709551615 at addr ffff88810efcfdb1 by task ismt_poc/485
[ 33.999450] Call Trace:
[ 34.001849] memcpy+0x20/0x60
[ 34.002077] ismt_access.cold+0x374/0x214b
[ 34.003382] __i2c_smbus_xfer+0x44f/0xfb0
[ 34.004007] i2c_smbus_xfer+0x10a/0x390
[ 34.004291] i2cdev_ioctl_smbus+0x2c8/0x710
[ 34.005196] i2cdev_ioctl+0x5ec/0x74c
Fix this bug by checking the size of 'data->block[0]' first.
| Product | Versions | Fixed in |
|---|---|---|
| linux/linux_kernel | ≥ 3.9, < 4.9.337 | 4.9.337 |
| linux/linux_kernel | ≥ 4.10, < 4.14.303 | 4.14.303 |
| linux/linux_kernel | ≥ 4.15, < 4.19.270 | 4.19.270 |
| linux/linux_kernel | ≥ 4.20, < 5.4.229 | 5.4.229 |
| linux/linux_kernel | ≥ 5.5, < 5.10.163 | 5.10.163 |
| linux/linux_kernel | ≥ 5.11, < 5.15.86 | 5.15.86 |
| linux/linux_kernel | ≥ 5.16, < 6.0.16 | 6.0.16 |
| linux/linux_kernel | ≥ 6.1, < 6.1.2 | 6.1.2 |