Ubuntu: (CVE-2022-49277): linux vulnerability

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

jffs2: fix memory leak in jffs2_do_mount_fs

If jffs2_build_filesystem() in jffs2_do_mount_fs() returns an error,
we can observe the following kmemleak report:

--------------------------------------------
unreferenced object 0xffff88811b25a640 (size 64):
comm "mount", pid 691, jiffies 4294957728 (age 71.952s)
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
[] kmem_cache_alloc_trace+0x584/0x880
[] jffs2_sum_init+0x86/0x130
[] jffs2_do_mount_fs+0x798/0xac0
[] jffs2_do_fill_super+0x383/0xc30
[] jffs2_fill_super+0x2ea/0x4c0
[...]
unreferenced object 0xffff88812c760000 (size 65536):
comm "mount", pid 691, jiffies 4294957728 (age 71.952s)
hex dump (first 32 bytes):
bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb ................
bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb ................
backtrace:
[] __kmalloc+0x6b9/0x910
[] jffs2_sum_init+0xd7/0x130
[] jffs2_do_mount_fs+0x798/0xac0
[] jffs2_do_fill_super+0x383/0xc30
[] jffs2_fill_super+0x2ea/0x4c0
[...]
--------------------------------------------

This is because the resources allocated in jffs2_sum_init() are not
released. Call jffs2_sum_exit() to release these resources to solve
the problem.