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.
Product status
5dc615520c4dfb358245680f1904bad61116648e (git) before b3ffad2f02db4aace6799fe0049508b8925eae45
5dc615520c4dfb358245680f1904bad61116648e (git) before 205a2182c51ffebaef54d643e3745e720cded08b
5dc615520c4dfb358245680f1904bad61116648e (git) before c74d95a5679741ef428974ab788f5b0758dc78ae
5dc615520c4dfb358245680f1904bad61116648e (git) before 48b904de2408af5f936f0e03f48dfcddeab58aa0
5dc615520c4dfb358245680f1904bad61116648e (git) before 7e2586991e36663c9bc48c828b83eab180ad30a9
6.1
Any version before 6.1
6.6.87 (semver)
6.12.23 (semver)
6.13.11 (semver)
6.14.2 (semver)
6.15 (original_commit_for_fix)
References
git.kernel.org/...c/b3ffad2f02db4aace6799fe0049508b8925eae45
git.kernel.org/...c/205a2182c51ffebaef54d643e3745e720cded08b
git.kernel.org/...c/c74d95a5679741ef428974ab788f5b0758dc78ae
git.kernel.org/...c/48b904de2408af5f936f0e03f48dfcddeab58aa0
git.kernel.org/...c/7e2586991e36663c9bc48c828b83eab180ad30a9