Baisong Zhong 8b256d2336 media: dvb-usb: az6027: fix null-ptr-deref in az6027_i2c_xfer()
[ Upstream commit 0ed554fd769a19ea8464bb83e9ac201002ef74ad ]

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.

Fix this by checking msg[i].len in az6027_i2c_xfer().

Link: https://lore.kernel.org/lkml/CAO4mrfcPHB5aQJO=mpqV+p8mPLNg-Fok0gw8gZ=zemAfMGTzMg@mail.gmail.com/

Link: https://lore.kernel.org/linux-media/20221120065918.2160782-1-zhongbaisong@huawei.com
Fixes: 76f9a820c867 ("V4L/DVB: AZ6027: Initial import of the driver")
Reported-by: Wei Chen <harperchen1110@gmail.com>
Signed-off-by: Baisong Zhong <zhongbaisong@huawei.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-01-18 11:41:06 +01:00
2023-01-18 11:40:59 +01:00
2019-09-22 10:34:46 -07:00
2019-11-10 13:41:59 -08:00
2022-12-19 12:24:17 +01:00

Linux kernel
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Please read the Documentation/process/changes.rst file, as it contains the
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