CVE-2022-48995

In the Linux kernel, the following vulnerability has been resolved:

Input: raydium_ts_i2c - fix memory leak in raydium_i2c_send()

There is a kmemleak when test the raydium_i2c_ts with bpf mock device:

unreferenced object 0xffff88812d3675a0 (size 8): comm python3, pid 349, jiffies 4294741067 (age 95.695s) hex dump (first 8 bytes): 11 0e 10 c0 01 00 04 00 …….. backtrace: [<0000000068427125>] __kmalloc+0x46/0x1b0 [<0000000090180f91>] raydium_i2c_send+0xd4/0x2bf [raydium_i2c_ts] [<000000006e631aee>] raydium_i2c_initialize.cold+0xbc/0x3e4 [raydium_i2c_ts] [<00000000dc6fcf38>] raydium_i2c_probe+0x3cd/0x6bc [raydium_i2c_ts] [<00000000a310de16>] i2c_device_probe+0x651/0x680 [<00000000f5a96bf3>] really_probe+0x17c/0x3f0 [<00000000096ba499>] __driver_probe_device+0xe3/0x170 [<00000000c5acb4d9>] driver_probe_device+0x49/0x120 [<00000000264fe082>] __device_attach_driver+0xf7/0x150 [<00000000f919423c>] bus_for_each_drv+0x114/0x180 [<00000000e067feca>] __device_attach+0x1e5/0x2d0 [<0000000054301fc2>] bus_probe_device+0x126/0x140 [<00000000aad93b22>] device_add+0x810/0x1130 [<00000000c086a53f>] i2c_new_client_device+0x352/0x4e0 [<000000003c2c248c>] of_i2c_register_device+0xf1/0x110 [<00000000ffec4177>] of_i2c_notify+0x100/0x160 unreferenced object 0xffff88812d3675c8 (size 8): comm python3, pid 349, jiffies 4294741070 (age 95.692s) hex dump (first 8 bytes): 22 00 36 2d 81 88 ff ff .6-…. backtrace: [<0000000068427125>] __kmalloc+0x46/0x1b0 [<0000000090180f91>] raydium_i2c_send+0xd4/0x2bf [raydium_i2c_ts] [<000000001d5c9620>] raydium_i2c_initialize.cold+0x223/0x3e4 [raydium_i2c_ts] [<00000000dc6fcf38>] raydium_i2c_probe+0x3cd/0x6bc [raydium_i2c_ts] [<00000000a310de16>] i2c_device_probe+0x651/0x680 [<00000000f5a96bf3>] really_probe+0x17c/0x3f0 [<00000000096ba499>] __driver_probe_device+0xe3/0x170 [<00000000c5acb4d9>] driver_probe_device+0x49/0x120 [<00000000264fe082>] __device_attach_driver+0xf7/0x150 [<00000000f919423c>] bus_for_each_drv+0x114/0x180 [<00000000e067feca>] __device_attach+0x1e5/0x2d0 [<0000000054301fc2>] bus_probe_device+0x126/0x140 [<00000000aad93b22>] device_add+0x810/0x1130 [<00000000c086a53f>] i2c_new_client_device+0x352/0x4e0 [<000000003c2c248c>] of_i2c_register_device+0xf1/0x110 [<00000000ffec4177>] of_i2c_notify+0x100/0x160

After BANK_SWITCH command from i2c BUS, no matter success or error happened, the tx_buf should be freed.

Weakness

The product does not sufficiently track and release allocated memory after it has been used, which slowly consumes remaining memory.

Affected Software

Potential Mitigations

• Choose a language or tool that provides automatic memory management, or makes manual memory management less error-prone.
• For example, glibc in Linux provides protection against free of invalid pointers.
• When using Xcode to target OS X or iOS, enable automatic reference counting (ARC) [REF-391].
• To help correctly and consistently manage memory when programming in C++, consider using a smart pointer class such as std::auto_ptr (defined by ISO/IEC ISO/IEC 14882:2003), std::shared_ptr and std::unique_ptr (specified by an upcoming revision of the C++ standard, informally referred to as C++ 1x), or equivalent solutions such as Boost.

References

• https://git.kernel.org/stable/c/097c1c7a28e3da8f2811ba532be6e81faab15aab
• https://git.kernel.org/stable/c/53b9b1201e34ccc895971218559123625c56fbcd
• https://git.kernel.org/stable/c/8c9a59939deb4bfafdc451100c03d1e848b4169b
• https://git.kernel.org/stable/c/a82869ac52f3d9db4b2cf8fd41edc2dee7a75a61