unicode: Fix utf8_load() error path

Vulnerability Description

In the Linux kernel, the following vulnerability has been resolved: unicode: Fix utf8_load() error path utf8_load() requests the symbol "utf8_data_table" and then checks if the requested UTF-8 version is supported. If it's unsupported, it tries to put the data table using symbol_put(). If an unsupported version is requested, symbol_put() fails like this: kernel BUG at kernel/module/main.c:786! RIP: 0010:__symbol_put+0x93/0xb0 Call Trace: <TASK> ? __die_body.cold+0x19/0x27 ? die+0x2e/0x50 ? do_trap+0xca/0x110 ? do_error_trap+0x65/0x80 ? __symbol_put+0x93/0xb0 ? exc_invalid_op+0x51/0x70 ? __symbol_put+0x93/0xb0 ? asm_exc_invalid_op+0x1a/0x20 ? __pfx_cmp_name+0x10/0x10 ? __symbol_put+0x93/0xb0 ? __symbol_put+0x62/0xb0 utf8_load+0xf8/0x150 That happens because symbol_put() expects the unique string that identify the symbol, instead of a pointer to the loaded symbol. Fix that by using such string.

References

• https://git.kernel.org/stable/c/4387cef540f36c2c9297460758cc2438305a24a0
• https://git.kernel.org/stable/c/c4b6c1781f6cc4e2283120ac8d873864b8056f21
• https://git.kernel.org/stable/c/6504dd27123966dc455494cb55217c04ca479121
• https://git.kernel.org/stable/c/89933f8ab3b4cad5ac14ea56a39947d1ffe7d0e3
• https://git.kernel.org/stable/c/156bb2c569cd869583c593d27a5bd69e7b2a4264