CVE-2023-52730

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

mmc: sdio: fix possible resource leaks in some error paths

If sdio_add_func() or sdio_init_func() fails, sdio_remove_func() can not release the resources, because the sdio function is not presented in these two cases, it wont call of_node_put() or put_device().

To fix these leaks, make sdio_func_present() only control whether device_del() needs to be called or not, then always call of_node_put() and put_device().

In error case in sdio_init_func(), the reference of card->dev is not get, to avoid redundant put in sdio_free_func_cis(), move the get_device() to sdio_alloc_func() and put_device() to sdio_release_func(), it can keep the get/put function be balanced.

Without this patch, while doing fault inject test, it can get the following leak reports, after this fix, the leak is gone.

unreferenced object 0xffff888112514000 (size 2048): comm kworker/3:2, pid 65, jiffies 4294741614 (age 124.774s) hex dump (first 32 bytes): 00 e0 6f 12 81 88 ff ff 60 58 8d 06 81 88 ff ff ..o…..`X…… 10 40 51 12 81 88 ff ff 10 40 51 12 81 88 ff ff .@Q……@Q….. backtrace: [<000000009e5931da>] kmalloc_trace+0x21/0x110 [<000000002f839ccb>] mmc_alloc_card+0x38/0xb0 [mmc_core] [<0000000004adcbf6>] mmc_sdio_init_card+0xde/0x170 [mmc_core] [<000000007538fea0>] mmc_attach_sdio+0xcb/0x1b0 [mmc_core] [<00000000d4fdeba7>] mmc_rescan+0x54a/0x640 [mmc_core]

unreferenced object 0xffff888112511000 (size 2048): comm kworker/3:2, pid 65, jiffies 4294741623 (age 124.766s) hex dump (first 32 bytes): 00 40 51 12 81 88 ff ff e0 58 8d 06 81 88 ff ff .@Q……X…… 10 10 51 12 81 88 ff ff 10 10 51 12 81 88 ff ff ..Q…….Q….. backtrace: [<000000009e5931da>] kmalloc_trace+0x21/0x110 [<00000000fcbe706c>] sdio_alloc_func+0x35/0x100 [mmc_core] [<00000000c68f4b50>] mmc_attach_sdio.cold.18+0xb1/0x395 [mmc_core] [<00000000d4fdeba7>] mmc_rescan+0x54a/0x640 [mmc_core]

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/1e06cf04239e202248c8fa356bf11449dc73cfbd
• https://git.kernel.org/stable/c/30716d9f0fa1766e522cf24c8a456244e4fc9931
• https://git.kernel.org/stable/c/5c7858adada31dbed042448cff6997dd6efc472a
• https://git.kernel.org/stable/c/605d9fb9556f8f5fb4566f4df1480f280f308ded
• https://git.kernel.org/stable/c/761db46b29b496946046d8cb33c7ea6de6bef36e
• https://git.kernel.org/stable/c/92ff03c2563c9b57a027c744750f3b7d2f261c58
• https://git.kernel.org/stable/c/f855d31bb38d663c3ba672345d7cce9324ba3b72
• https://git.kernel.org/stable/c/1e06cf04239e202248c8fa356bf11449dc73cfbd
• https://git.kernel.org/stable/c/30716d9f0fa1766e522cf24c8a456244e4fc9931
• https://git.kernel.org/stable/c/5c7858adada31dbed042448cff6997dd6efc472a
• https://git.kernel.org/stable/c/605d9fb9556f8f5fb4566f4df1480f280f308ded
• https://git.kernel.org/stable/c/761db46b29b496946046d8cb33c7ea6de6bef36e
• https://git.kernel.org/stable/c/92ff03c2563c9b57a027c744750f3b7d2f261c58
• https://git.kernel.org/stable/c/f855d31bb38d663c3ba672345d7cce9324ba3b72