Bug 2350348 (CVE-2024-58070)

Summary: CVE-2024-58070 kernel: bpf: bpf_local_storage: Always use bpf_mem_alloc in PREEMPT_RT
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: low Docs Contact:
Priority: low    
Version: unspecifiedCC: dfreiber, drow, jburrell, vkumar
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
Whiteboard:
Fixed In Version: Doc Type: ---
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:

Description OSIDB Bzimport 2025-03-06 16:01:13 UTC
In the Linux kernel, the following vulnerability has been resolved:

bpf: bpf_local_storage: Always use bpf_mem_alloc in PREEMPT_RT

In PREEMPT_RT, kmalloc(GFP_ATOMIC) is still not safe in non preemptible
context. bpf_mem_alloc must be used in PREEMPT_RT. This patch is
to enforce bpf_mem_alloc in the bpf_local_storage when CONFIG_PREEMPT_RT
is enabled.

[   35.118559] BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:48
[   35.118566] in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 1832, name: test_progs
[   35.118569] preempt_count: 1, expected: 0
[   35.118571] RCU nest depth: 1, expected: 1
[   35.118577] INFO: lockdep is turned off.
    ...
[   35.118647]  __might_resched+0x433/0x5b0
[   35.118677]  rt_spin_lock+0xc3/0x290
[   35.118700]  ___slab_alloc+0x72/0xc40
[   35.118723]  __kmalloc_noprof+0x13f/0x4e0
[   35.118732]  bpf_map_kzalloc+0xe5/0x220
[   35.118740]  bpf_selem_alloc+0x1d2/0x7b0
[   35.118755]  bpf_local_storage_update+0x2fa/0x8b0
[   35.118784]  bpf_sk_storage_get_tracing+0x15a/0x1d0
[   35.118791]  bpf_prog_9a118d86fca78ebb_trace_inet_sock_set_state+0x44/0x66
[   35.118795]  bpf_trace_run3+0x222/0x400
[   35.118820]  __bpf_trace_inet_sock_set_state+0x11/0x20
[   35.118824]  trace_inet_sock_set_state+0x112/0x130
[   35.118830]  inet_sk_state_store+0x41/0x90
[   35.118836]  tcp_set_state+0x3b3/0x640

There is no need to adjust the gfp_flags passing to the
bpf_mem_cache_alloc_flags() which only honors the GFP_KERNEL.
The verifier has ensured GFP_KERNEL is passed only in sleepable context.

It has been an old issue since the first introduction of the
bpf_local_storage ~5 years ago, so this patch targets the bpf-next.

bpf_mem_alloc is needed to solve it, so the Fixes tag is set
to the commit when bpf_mem_alloc was first used in the bpf_local_storage.

Comment 1 Mauro Matteo Cascella 2025-03-06 17:17:23 UTC
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2025030611-CVE-2024-58070-3c5f@gregkh/T