CVE-2023-53637

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

media: i2c: ov772x: Fix memleak in ov772x_probe()

A memory leak was reported when testing ov772x with bpf mock device:

AssertionError: unreferenced object 0xffff888109afa7a8 (size 8): comm python3, pid 279, jiffies 4294805921 (age 20.681s) hex dump (first 8 bytes): 80 22 88 15 81 88 ff ff ……. backtrace: [<000000009990b438>] __kmalloc_node+0x44/0x1b0 [<000000009e32f7d7>] kvmalloc_node+0x34/0x180 [<00000000faf48134>] v4l2_ctrl_handler_init_class+0x11d/0x180 [videodev] [<00000000da376937>] ov772x_probe+0x1c3/0x68c [ov772x] [<000000003f0d225e>] i2c_device_probe+0x28d/0x680 [<00000000e0b6db89>] really_probe+0x17c/0x3f0 [<000000001b19fcee>] __driver_probe_device+0xe3/0x170 [<0000000048370519>] driver_probe_device+0x49/0x120 [<000000005ead07a0>] __device_attach_driver+0xf7/0x150 [<0000000043f452b8>] bus_for_each_drv+0x114/0x180 [<00000000358e5596>] __device_attach+0x1e5/0x2d0 [<0000000043f83c5d>] bus_probe_device+0x126/0x140 [<00000000ee0f3046>] device_add+0x810/0x1130 [<00000000e0278184>] i2c_new_client_device+0x359/0x4f0 [<0000000070baf34f>] of_i2c_register_device+0xf1/0x110 [<00000000a9f2159d>] of_i2c_notify+0x100/0x160 unreferenced object 0xffff888119825c00 (size 256): comm python3, pid 279, jiffies 4294805921 (age 20.681s) hex dump (first 32 bytes): 00 b4 a5 17 81 88 ff ff 00 5e 82 19 81 88 ff ff ………^…… 10 5c 82 19 81 88 ff ff 10 5c 82 19 81 88 ff ff ………….. backtrace: [<000000009990b438>] __kmalloc_node+0x44/0x1b0 [<000000009e32f7d7>] kvmalloc_node+0x34/0x180 [<0000000073d88e0b>] v4l2_ctrl_new.cold+0x19b/0x86f [videodev] [<00000000b1f576fb>] v4l2_ctrl_new_std+0x16f/0x210 [videodev] [<00000000caf7ac99>] ov772x_probe+0x1fa/0x68c [ov772x] [<000000003f0d225e>] i2c_device_probe+0x28d/0x680 [<00000000e0b6db89>] really_probe+0x17c/0x3f0 [<000000001b19fcee>] __driver_probe_device+0xe3/0x170 [<0000000048370519>] driver_probe_device+0x49/0x120 [<000000005ead07a0>] __device_attach_driver+0xf7/0x150 [<0000000043f452b8>] bus_for_each_drv+0x114/0x180 [<00000000358e5596>] __device_attach+0x1e5/0x2d0 [<0000000043f83c5d>] bus_probe_device+0x126/0x140 [<00000000ee0f3046>] device_add+0x810/0x1130 [<00000000e0278184>] i2c_new_client_device+0x359/0x4f0 [<0000000070baf34f>] of_i2c_register_device+0xf1/0x110

The reason is that if priv->hdl.error is set, ov772x_probe() jumps to the error_mutex_destroy without doing v4l2_ctrl_handler_free(), and all resources allocated in v4l2_ctrl_handler_init() and v4l2_ctrl_new_std() are leaked.

Weakness

The product does not sufficiently track and release allocated memory after it has been used, making the memory unavailable for reallocation and reuse.

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/1da495101ef7507eb4f4b1dbec2874d740eff251
• https://git.kernel.org/stable/c/448ce1cd50387b1345ec14eb191ef05f7afc2a26
• https://git.kernel.org/stable/c/7485edb2b6ca5960205c0a49bedfd09bba30e521
• https://git.kernel.org/stable/c/ac93f8ac66e60227bed42d5a023f0e6c15b52c0a
• https://git.kernel.org/stable/c/c86d760c1c6855a6131e78d0ddacc48c79324ac3
• https://git.kernel.org/stable/c/cc3b6011d7a9f149489eb9420c6305a779162c57
• https://git.kernel.org/stable/c/dfaafeb8e9537969e8dba75491f732478c7fa9d6