Bug 2363383 (CVE-2022-49853)

Summary: CVE-2022-49853 kernel: net: macvlan: fix memory leaks of macvlan_common_newlink
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: dfreiber, drow, jburrell, vkumar
Target Milestone: ---Keywords: Security
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Hardware: All   
OS: Linux   
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Description OSIDB Bzimport 2025-05-01 15:02:31 UTC
In the Linux kernel, the following vulnerability has been resolved:

net: macvlan: fix memory leaks of macvlan_common_newlink

kmemleak reports memory leaks in macvlan_common_newlink, as follows:

 ip link add link eth0 name .. type macvlan mode source macaddr add
 <MAC-ADDR>

kmemleak reports:

unreferenced object 0xffff8880109bb140 (size 64):
  comm "ip", pid 284, jiffies 4294986150 (age 430.108s)
  hex dump (first 32 bytes):
    00 00 00 00 00 00 00 00 b8 aa 5a 12 80 88 ff ff  ..........Z.....
    80 1b fa 0d 80 88 ff ff 1e ff ac af c7 c1 6b 6b  ..............kk
  backtrace:
    [<ffffffff813e06a7>] kmem_cache_alloc_trace+0x1c7/0x300
    [<ffffffff81b66025>] macvlan_hash_add_source+0x45/0xc0
    [<ffffffff81b66a67>] macvlan_changelink_sources+0xd7/0x170
    [<ffffffff81b6775c>] macvlan_common_newlink+0x38c/0x5a0
    [<ffffffff81b6797e>] macvlan_newlink+0xe/0x20
    [<ffffffff81d97f8f>] __rtnl_newlink+0x7af/0xa50
    [<ffffffff81d98278>] rtnl_newlink+0x48/0x70
    ...

In the scenario where the macvlan mode is configured as 'source',
macvlan_changelink_sources() will be execured to reconfigure list of
remote source mac addresses, at the same time, if register_netdevice()
return an error, the resource generated by macvlan_changelink_sources()
is not cleaned up.

Using this patch, in the case of an error, it will execute
macvlan_flush_sources() to ensure that the resource is cleaned up.

Comment 1 Avinash Hanwate 2025-05-02 04:05:48 UTC
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2025050144-CVE-2022-49853-a5ef@gregkh/T