CVE-2022-49890

/// Technical description

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

capabilities: fix potential memleak on error path from vfs_getxattr_alloc()

In cap_inode_getsecurity(), we will use vfs_getxattr_alloc() to

complete the memory allocation of tmpbuf, if we have completed

the memory allocation of tmpbuf, but failed to call handler->get(...),

there will be a memleak in below logic:

|-- ret = (int)vfs_getxattr_alloc(mnt_userns, ...)

| /* ^^^ alloc for tmpbuf */

|-- value = krealloc(*xattr_value, error + 1, flags)

| /* ^^^ alloc memory */

|-- error = handler->get(handler, ...)

| /* error! */

|-- *xattr_value = value

| /* xattr_value is &tmpbuf (memory leak!) */

So we will try to free(tmpbuf) after vfs_getxattr_alloc() fails to fix it.

[PM: subject line and backtrace tweaks]

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References