CVE-2022-49878

/// Technical description

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

bpf, verifier: Fix memory leak in array reallocation for stack state

If an error (NULL) is returned by krealloc(), callers of realloc_array()

were setting their allocation pointers to NULL, but on error krealloc()

does not touch the original allocation. This would result in a memory

resource leak. Instead, free the old allocation on the error handling

path.

The memory leak information is as follows as also reported by Zhengchao:

unreferenced object 0xffff888019801800 (size 256):

comm "bpf_repo", pid 6490, jiffies 4294959200 (age 17.170s)

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:

[<00000000b211474b>] __kmalloc_node_track_caller+0x45/0xc0

[<0000000086712a0b>] krealloc+0x83/0xd0

[<00000000139aab02>] realloc_array+0x82/0xe2

[<00000000b1ca41d1>] grow_stack_state+

/// 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