CVE-2021-47180

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

NFC: nci: fix memory leak in nci_allocate_device

nfcmrvl_disconnect fails to free the hci_dev field in struct nci_dev. Fix this by freeing hci_dev in nci_free_device.

BUG: memory leak unreferenced object 0xffff888111ea6800 (size 1024): comm kworker/1:0, pid 19, jiffies 4294942308 (age 13.580s) hex dump (first 32 bytes): 00 00 00 00 00 00 00 00 00 60 fd 0c 81 88 ff ff ………`…… 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ……………. backtrace: [<000000004bc25d43>] kmalloc include/linux/slab.h:552 [inline] [<000000004bc25d43>] kzalloc include/linux/slab.h:682 [inline] [<000000004bc25d43>] nci_hci_allocate+0x21/0xd0 net/nfc/nci/hci.c:784 [<00000000c59cff92>] nci_allocate_device net/nfc/nci/core.c:1170 [inline] [<00000000c59cff92>] nci_allocate_device+0x10b/0x160 net/nfc/nci/core.c:1132 [<00000000006e0a8e>] nfcmrvl_nci_register_dev+0x10a/0x1c0 drivers/nfc/nfcmrvl/main.c:153 [<000000004da1b57e>] nfcmrvl_probe+0x223/0x290 drivers/nfc/nfcmrvl/usb.c:345 [<00000000d506aed9>] usb_probe_interface+0x177/0x370 drivers/usb/core/driver.c:396 [<00000000bc632c92>] really_probe+0x159/0x4a0 drivers/base/dd.c:554 [<00000000f5009125>] driver_probe_device+0x84/0x100 drivers/base/dd.c:740 [<000000000ce658ca>] __device_attach_driver+0xee/0x110 drivers/base/dd.c:846 [<000000007067d05f>] bus_for_each_drv+0xb7/0x100 drivers/base/bus.c:431 [<00000000f8e13372>] __device_attach+0x122/0x250 drivers/base/dd.c:914 [<000000009cf68860>] bus_probe_device+0xc6/0xe0 drivers/base/bus.c:491 [<00000000359c965a>] device_add+0x5be/0xc30 drivers/base/core.c:3109 [<00000000086e4bd3>] usb_set_configuration+0x9d9/0xb90 drivers/usb/core/message.c:2164 [<00000000ca036872>] usb_generic_driver_probe+0x8c/0xc0 drivers/usb/core/generic.c:238 [<00000000d40d36f6>] usb_probe_device+0x5c/0x140 drivers/usb/core/driver.c:293 [<00000000bc632c92>] really_probe+0x159/0x4a0 drivers/base/dd.c:554

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/0365701bc44e078682ee1224866a71897495c7ef
• https://git.kernel.org/stable/c/2c2fb2df46ea866b49fea5ec7112ec3cd4896c74
• https://git.kernel.org/stable/c/448a1cb12977f52142e6feb12022c59662d88dc1
• https://git.kernel.org/stable/c/4a621621c7af3cec21c47c349b30cd9c3cea11c8
• https://git.kernel.org/stable/c/65234f50a90b64b335cbb9164b8a98c2a0d031dd
• https://git.kernel.org/stable/c/af2a4426baf71163c0c354580ae98c7888a9aba7
• https://git.kernel.org/stable/c/b34cb7ac32cc8e5471dc773180ea9ae676b1a745
• https://git.kernel.org/stable/c/e0652f8bb44d6294eeeac06d703185357f25d50b
• https://git.kernel.org/stable/c/0365701bc44e078682ee1224866a71897495c7ef
• https://git.kernel.org/stable/c/2c2fb2df46ea866b49fea5ec7112ec3cd4896c74
• https://git.kernel.org/stable/c/448a1cb12977f52142e6feb12022c59662d88dc1
• https://git.kernel.org/stable/c/4a621621c7af3cec21c47c349b30cd9c3cea11c8
• https://git.kernel.org/stable/c/65234f50a90b64b335cbb9164b8a98c2a0d031dd
• https://git.kernel.org/stable/c/af2a4426baf71163c0c354580ae98c7888a9aba7
• https://git.kernel.org/stable/c/b34cb7ac32cc8e5471dc773180ea9ae676b1a745
• https://git.kernel.org/stable/c/e0652f8bb44d6294eeeac06d703185357f25d50b