CVE-2022-49800

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

tracing: Fix memory leak in testgensynthcmd() and testemptysynthevent()

testgensynthcmd() only free buf in fail path, hence buf will leak when there is no failure. Add kfree(buf) to prevent the memleak. The same reason and solution in testemptysynthevent().

unreferenced object 0xffff8881127de000 (size 2048): comm "modprobe", pid 247, jiffies 4294972316 (age 78.756s) hex dump (first 32 bytes): 20 67 65 6e 5f 73 79 6e 74 68 5f 74 65 73 74 20 gensynthtest 20 70 69 64 5f 74 20 6e 65 78 74 5f 70 69 64 5f pidt nextpid_ backtrace: [<000000004254801a>] kmalloctrace+0x26/0x100 [<0000000039eb1cf5>] 0xffffffffa00083cd [<000000000e8c3bc8>] 0xffffffffa00086ba [<00000000c293d1ea>] dooneinitcall+0xdb/0x480 [<00000000aa189e6d>] doinitmodule+0x1cf/0x680 [<00000000d513222b>] loadmodule+0x6a50/0x70a0 [<000000001fd4d529>] _dosysfinitmodule+0x12f/0x1c0 [<00000000b36c4c0f>] dosyscall64+0x3f/0x90 [<00000000bbf20cf3>] entrySYSCALL64afterhwframe+0x63/0xcd unreferenced object 0xffff8881127df000 (size 2048): comm "modprobe", pid 247, jiffies 4294972324 (age 78.728s) hex dump (first 32 bytes): 20 65 6d 70 74 79 5f 73 79 6e 74 68 5f 74 65 73 emptysynthtes 74 20 20 70 69 64 5f 74 20 6e 65 78 74 5f 70 69 t pidt nextpi backtrace: [<000000004254801a>] kmalloctrace+0x26/0x100 [<00000000d4db9a3d>] 0xffffffffa0008071 [<00000000c31354a5>] 0xffffffffa00086ce [<00000000c293d1ea>] dooneinitcall+0xdb/0x480 [<00000000aa189e6d>] doinitmodule+0x1cf/0x680 [<00000000d513222b>] loadmodule+0x6a50/0x70a0 [<000000001fd4d529>] _dosysfinitmodule+0x12f/0x1c0 [<00000000b36c4c0f>] dosyscall64+0x3f/0x90 [<00000000bbf20cf3>] entrySYSCALL64afterhwframe+0x63/0xcd