CVE-2023-52447
Assigner: Linux
Published: 2024-02-22T16:21:39.032Z
State: PUBLISHED
descriptions: value: In the Linux kernel, the following vulnerability has been resolved:

bpf: Defer the free of inner map when necessary

When updating or deleting an inner map in map array or map htab, the map
may still be accessed by non-sleepable program or sleepable program.
However bpf_map_fd_put_ptr() decreases the ref-counter of the inner map
directly through bpf_map_put(), if the ref-counter is the last one
(which is true for most cases), the inner map will be freed by
ops->map_free() in a kworker. But for now, most .map_free() callbacks
don't use synchronize_rcu() or its variants to wait for the elapse of a
RCU grace period, so after the invocation of ops->map_free completes,
the bpf program which is accessing the inner map may incur
use-after-free problem.

Fix the free of inner map by invoking bpf_map_free_deferred() after both
one RCU grace period and one tasks trace RCU grace period if the inner
map has been removed from the outer map before. The deferment is
accomplished by using call_rcu() or call_rcu_tasks_trace() when
releasing the last ref-counter of bpf map. The newly-added rcu_head
field in bpf_map shares the same storage space with work field to
reduce the size of bpf_map.
affected: product: Linux
vendor: Linux
defaultStatus: unaffected
repo: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
versions: version: bba1dc0b55ac
lessThan: 90c445799fd1
status: affected
versionType: git
version: bba1dc0b55ac
lessThan: 37d98fb9c314
status: affected
versionType: git
version: bba1dc0b55ac
lessThan: 62fca83303d6
status: affected
versionType: git
version: bba1dc0b55ac
lessThan: f91cd728b10c
status: affected
versionType: git
version: bba1dc0b55ac
lessThan: bfd9b20c4862
status: affected
versionType: git
version: bba1dc0b55ac
lessThan: 876673364161
status: affected
versionType: git
product: Linux
vendor: Linux
defaultStatus: affected
repo: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
versions: version: 5.9
status: affected
version: 0
lessThan: 5.9
status: unaffected
versionType: custom
version: 5.10.214
lessThanOrEqual: 5.10.*
status: unaffected
versionType: custom
version: 5.15.153
lessThanOrEqual: 5.15.*
status: unaffected
versionType: custom
version: 6.1.75
lessThanOrEqual: 6.1.*
status: unaffected
versionType: custom
version: 6.6.14
lessThanOrEqual: 6.6.*
status: unaffected
versionType: custom
version: 6.7.2
lessThanOrEqual: 6.7.*
status: unaffected
versionType: custom
version: 6.8
lessThanOrEqual: *
status: unaffected
versionType: original_commit_for_fix
title: bpf: Defer the free of inner map when necessary
x_generator: engine: bippy-5f0117140d9a