Bug 2395349 (CVE-2022-50272)

Summary: CVE-2022-50272 kernel: media: dvb-usb: az6027: fix null-ptr-deref in az6027_i2c_xfer()
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
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OS: Linux   
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Description OSIDB Bzimport 2025-09-15 15:08:57 UTC 
In the Linux kernel, the following vulnerability has been resolved:

media: dvb-usb: az6027: fix null-ptr-deref in az6027_i2c_xfer()

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().
Comment 1 Jon Moroney 2025-09-15 20:36:49 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2025091505-CVE-2022-50272-4120@gregkh/T