CVE-2024-57982
Severity CVSS v4.0:
Pending analysis
Type:
CWE-125
Out-of-bounds Read
Publication date:
27/02/2025
Last modified:
07/03/2025
Description
In the Linux kernel, the following vulnerability has been resolved:<br />
<br />
xfrm: state: fix out-of-bounds read during lookup<br />
<br />
lookup and resize can run in parallel.<br />
<br />
The xfrm_state_hash_generation seqlock ensures a retry, but the hash<br />
functions can observe a hmask value that is too large for the new hlist<br />
array.<br />
<br />
rehash does:<br />
rcu_assign_pointer(net->xfrm.state_bydst, ndst) [..]<br />
net->xfrm.state_hmask = nhashmask;<br />
<br />
While state lookup does:<br />
h = xfrm_dst_hash(net, daddr, saddr, tmpl->reqid, encap_family);<br />
hlist_for_each_entry_rcu(x, net->xfrm.state_bydst + h, bydst) {<br />
<br />
This is only safe in case the update to state_bydst is larger than<br />
net->xfrm.xfrm_state_hmask (or if the lookup function gets<br />
serialized via state spinlock again).<br />
<br />
Fix this by prefetching state_hmask and the associated pointers.<br />
The xfrm_state_hash_generation seqlock retry will ensure that the pointer<br />
and the hmask will be consistent.<br />
<br />
The existing helpers, like xfrm_dst_hash(), are now unsafe for RCU side,<br />
add lockdep assertions to document that they are only safe for insert<br />
side.<br />
<br />
xfrm_state_lookup_byaddr() uses the spinlock rather than RCU.<br />
AFAICS this is an oversight from back when state lookup was converted to<br />
RCU, this lock should be replaced with RCU in a future patch.
Impact
Base Score 3.x
7.10
Severity 3.x
HIGH
Vulnerable products and versions
CPE | From | Up to |
---|---|---|
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | 4.9 (including) | 6.12.13 (excluding) |
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | 6.13 (including) | 6.13.2 (excluding) |
To consult the complete list of CPE names with products and versions, see this page