Description
In the Linux kernel, the following vulnerability has been resolved:
LoongArch: BPF: Fix off-by-one error in build_prologue()
Vincent reported that running BPF progs with tailcalls on LoongArch causes kernel hard lockup. Debugging the issues shows that the JITed image missing a jirl instruction at the end of the epilogue.
There are two passes in JIT compiling, the first pass set the flags and the second pass generates JIT code based on those flags. With BPF progs mixing bpf2bpf and tailcalls, build_prologue() generates N insns in the first pass and then generates N+1 insns in the second pass. This makes epilogue_offset off by one and we will jump to some unexpected insn and cause lockup. Fix this by inserting a nop insn.
Metrics
CVSS 3.1 5.5/10
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:HWeakness enumeration
Affected software
| Vendor | Product | Versions |
|---|---|---|
| Linux | Linux | >= 5dc615520c4dfb358245680f1904bad61116648e, < b3ffad2f02db4aace6799fe0049508b8925eae45; >= 5dc615520c4dfb358245680f1904bad61116648e, < 205a2182c51ffebaef54d643e3745e720cded08b; >= 5dc615520c4dfb358245680f1904bad61116648e, < c74d95a5679741ef428974ab788f5b0758dc78ae; >= 5dc615520c4dfb358245680f1904bad61116648e, < 48b904de2408af5f936f0e03f48dfcddeab58aa0; >= 5dc615520c4dfb358245680f1904bad61116648e, < 7e2586991e36663c9bc48c828b83eab180ad30a9 |
| Linux | Linux | 6.1 |
References
- https://git.kernel.org/stable/c/205a2182c51ffebaef54d643e3745e720cded08bPatch
- https://git.kernel.org/stable/c/48b904de2408af5f936f0e03f48dfcddeab58aa0Patch
- https://git.kernel.org/stable/c/7e2586991e36663c9bc48c828b83eab180ad30a9Patch
- https://git.kernel.org/stable/c/b3ffad2f02db4aace6799fe0049508b8925eae45Patch
- https://git.kernel.org/stable/c/c74d95a5679741ef428974ab788f5b0758dc78aePatch
Timeline
- Published
- Apr 18, 2025
- Last modified
- Jul 30, 2026
- NVD status
- Modified