In the Linux kernel, the following vulnerability has been resolved:
ipv4: stop exception dump when nexthop group shrinks
Commit 4ce5dc9316de ("inet: switch inet_dump_fib() to RCU
protection") allowed IPv4 FIB dumps to run concurrently with nexthop
replacement.
fib_dump_info_fnhe() uses fib_info_num_path() as the loop bound,
then fib_info_nhc() independently reloads nh->nh_grp. If
RTM_NEWNEXTHOP replaces a group with fewer paths between those loads,
fib_info_nhc() returns NULL and the dump dereferences it through
nhc_flags. Stop the walk when the indexed path is absent.
Nexthop groups are dense, so the current snapshot has no later path.
Ссылки 4
https://git.kernel.org/stable/c/21cba134c30c17ae55f468b5809336437df5d7e6
416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/4f4afc07dcb2edd4f9afa36595373f8cdb9b58c2
416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/b9a30bb7b831e8c5a47fadbdf1760918aaf009cc
416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/f91e472821e32f58b03eb631e20a67157e2b928b
416baaa9-dc9f-4396-8d5f-8c081fb06d67