Description ljubomir 2023-02-22 08:47:40 UTC

Description of problem:

Wei Chen reports a kernel bug as blew:

general protection fault, probably for non-canonical address
    KASAN: null-ptr-deref in range [0x0000000000000010-0x0000000000000017]
    ...
    Call Trace:
    <TASK>
    __i2c_transfer+0x77e/0x1930 drivers/i2c/i2c-core-base.c:2109
    i2c_transfer+0x1d5/0x3d0 drivers/i2c/i2c-core-base.c:2170
    i2cdev_ioctl_rdwr+0x393/0x660 drivers/i2c/i2c-dev.c:297
    i2cdev_ioctl+0x75d/0x9f0 drivers/i2c/i2c-dev.c:458
    vfs_ioctl fs/ioctl.c:51 [inline]
    __do_sys_ioctl fs/ioctl.c:870 [inline]
    __se_sys_ioctl+0xfb/0x170 fs/ioctl.c:856
    do_syscall_x64 arch/x86/entry/common.c:50 [inline]
    do_syscall_64+0x3d/0x90 arch/x86/entry/common.c:80
    entry_SYSCALL_64_after_hwframe+0x63/0xcd
    RIP: 0033:0x7fd834a8bded

In az6027_i2c_xfer(), if msg[i].addr is 0x99,
a null-ptr-deref will caused when accessing msg[i].buf.
For msg[i].len is 0 and msg[i].buf is null.