bpf: Use RCU-safe iteration in dev_map_redirect_multi() SKB path
The DEVMAP_HASH branch in dev_map_redirect_multi() uses
hlist_for_each_entry_safe() to iterate hash buckets, but this function
runs under RCU protection (called from xdp_do_generic_redirect_map()
in softirq context). Concurrent writers (__dev_map_hash_update_elem,
dev_map_hash_delete_elem) modify the list using RCU primitives
(hlist_add_head_rcu, hlist_del_rcu).
hlist_for_each_entry_safe() performs plain pointer dereferences without
rcu_dereference(), missing the acquire barrier needed to pair with
writers' rcu_assign_pointer(). On weakly-ordered architectures (ARM64,
POWER), a reader can observe a partially-constructed node. It also
defeats CONFIG_PROVE_RCU lockdep validation and KCSAN data-race
detection.
Replace with hlist_for_each_entry_rcu() using rcu_read_lock_bh_held()
as the lockdep condition, consistent with the rcu_dereference_check()
used in the DEVMAP (non-hash) branch of the same functions. Also fix
the same incorrect lockdep_is_held(&dtab->index_lock) condition in
dev_map_enqueue_multi(), where the lock is not held either.
| Source | ID | Title |
|---|---|---|
Debian DLA |
DLA-4665-1 | linux security update |
Debian DLA |
DLA-4671-1 | linux-6.1 security update |
Ubuntu USN |
USN-8566-1 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-8567-1 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-8568-1 | Linux kernel (OEM) vulnerabilities |
Ubuntu USN |
USN-8569-1 | Linux kernel (HWE) vulnerabilities |
Ubuntu USN |
USN-8574-1 | Linux kernel (GCP FIPS) vulnerabilities |
Ubuntu USN |
USN-8575-1 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-8576-1 | Linux kernel (NVIDIA Tegra) vulnerabilities |
Ubuntu USN |
USN-8593-1 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-8574-2 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-8595-1 | Linux kernel (Oracle) vulnerabilities |
Ubuntu USN |
USN-8596-1 | Linux kernel (NVIDIA) vulnerabilities |
Ubuntu USN |
USN-8575-2 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-8576-2 | Linux kernel (NVIDIA Tegra) vulnerabilities |
Ubuntu USN |
USN-8575-3 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-8595-2 | Linux kernel (AWS) vulnerabilities |
Ubuntu USN |
USN-8603-1 | Linux kernel (Azure) vulnerabilities |
Ubuntu USN |
USN-8606-1 | Linux kernel (Azure) vulnerabilities |
Ubuntu USN |
USN-8607-1 | Linux kernel (Azure CVM) vulnerabilities |
Ubuntu USN |
USN-8608-1 | Linux kernel (Azure FIPS) vulnerabilities |
Ubuntu USN |
USN-8609-1 | Linux kernel (Azure CVM) vulnerabilities |
Ubuntu USN |
USN-8610-1 | Linux kernel (Azure CVM) vulnerabilities |
Solution
No solution given by the vendor.
Workaround
No workaround given by the vendor.
Sun, 28 Jun 2026 08:00:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Metrics |
cvssV3_1
|
cvssV3_1
|
Thu, 25 Jun 2026 16:00:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Weaknesses | CWE-603 CWE-815 |
Thu, 25 Jun 2026 12:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Weaknesses | CWE-821 | |
| References |
| |
| Metrics |
threat_severity
|
cvssV3_1
|
Wed, 24 Jun 2026 21:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Weaknesses | CWE-603 CWE-815 |
Wed, 24 Jun 2026 17:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | In the Linux kernel, the following vulnerability has been resolved: bpf: Use RCU-safe iteration in dev_map_redirect_multi() SKB path The DEVMAP_HASH branch in dev_map_redirect_multi() uses hlist_for_each_entry_safe() to iterate hash buckets, but this function runs under RCU protection (called from xdp_do_generic_redirect_map() in softirq context). Concurrent writers (__dev_map_hash_update_elem, dev_map_hash_delete_elem) modify the list using RCU primitives (hlist_add_head_rcu, hlist_del_rcu). hlist_for_each_entry_safe() performs plain pointer dereferences without rcu_dereference(), missing the acquire barrier needed to pair with writers' rcu_assign_pointer(). On weakly-ordered architectures (ARM64, POWER), a reader can observe a partially-constructed node. It also defeats CONFIG_PROVE_RCU lockdep validation and KCSAN data-race detection. Replace with hlist_for_each_entry_rcu() using rcu_read_lock_bh_held() as the lockdep condition, consistent with the rcu_dereference_check() used in the DEVMAP (non-hash) branch of the same functions. Also fix the same incorrect lockdep_is_held(&dtab->index_lock) condition in dev_map_enqueue_multi(), where the lock is not held either. | |
| Title | bpf: Use RCU-safe iteration in dev_map_redirect_multi() SKB path | |
| First Time appeared |
Linux
Linux linux Kernel |
|
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Linux
Linux linux Kernel |
|
| References |
|
|
Projects
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Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2026-06-28T06:39:18.779Z
Reserved: 2026-06-09T07:44:35.384Z
Link: CVE-2026-53096
No data.
No data.
OpenCVE Enrichment
Updated: 2026-06-28T14:30:07Z
Debian DLA
Ubuntu USN