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CVE-2024-43840

bpf, arm64: Fix trampoline for BPF_TRAMP_F_CALL_ORIG

EPSS 0.2%
Vexday Risk Score
3Low
SSVC decision (CISA)
Track
No exploitation signal → monitor
CVSS EPSS 0.2%KEV nãoPoC Nuclei Metasploit Patch
Lifecycle
17 Aug 2024Published on NVD
Recommendation: Monitor — no exploitation signal at the moment.
In the Linux kernel, the following vulnerability has been resolved: bpf, arm64: Fix trampoline for BPF_TRAMP_F_CALL_ORIG When BPF_TRAMP_F_CALL_ORIG is set, the trampoline calls __bpf_tramp_enter() and __bpf_tramp_exit() functions, passing them the struct bpf_tramp_image *im pointer as an argument in R0. The trampoline generation code uses emit_addr_mov_i64() to emit instructions for moving the bpf_tramp_image address into R0, but emit_addr_mov_i64() assumes the address to be in the vmalloc() space and uses only 48 bits. Because bpf_tramp_image is allocated using kzalloc(), its address can use more than 48-bits, in this case the trampoline will pass an invalid address to __bpf_tramp_enter/exit() causing a kernel crash. Fix this by using emit_a64_mov_i64() in place of emit_addr_mov_i64() as it can work with addresses that are greater than 48-bits.
Affected products
Linux · Linux