Vulnerabilities > CVE-2024-58070 - Improper Locking vulnerability in Linux Kernel
Summary
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.
Vulnerable Configurations
Common Weakness Enumeration (CWE)
Common Attack Pattern Enumeration and Classification (CAPEC)
- Leveraging Race Conditions This attack targets a race condition occurring when multiple processes access and manipulate the same resource concurrently and the outcome of the execution depends on the particular order in which the access takes place. The attacker can leverage a race condition by "running the race", modifying the resource and modifying the normal execution flow. For instance a race condition can occur while accessing a file, the attacker can trick the system by replacing the original file with his version and cause the system to read the malicious file.
- Leveraging Race Conditions via Symbolic Links This attack leverages the use of symbolic links (Symlinks) in order to write to sensitive files. An attacker can create a Symlink link to a target file not otherwise accessible to her. When the privileged program tries to create a temporary file with the same name as the Symlink link, it will actually write to the target file pointed to by the attackers' Symlink link. If the attacker can insert malicious content in the temporary file she will be writing to the sensitive file by using the Symlink. The race occurs because the system checks if the temporary file exists, then creates the file. The attacker would typically create the Symlink during the interval between the check and the creation of the temporary file.