From: Christophe Leroy christophe.leroy@csgroup.eu

stable inclusion from stable-v6.6.37 commit fdd411af8178edc6b7bf260f8fa4fba1bedd0a6d category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/IAGEOM CVE: CVE-2024-42068

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...

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[ Upstream commit 7d2cc63eca0c993c99d18893214abf8f85d566d8 ]

set_memory_ro() can fail, leaving memory unprotected.

Check its return and take it into account as an error.

Link: https://github.com/KSPP/linux/issues/7 Signed-off-by: Christophe Leroy christophe.leroy@csgroup.eu Cc: linux-hardening@vger.kernel.org linux-hardening@vger.kernel.org Reviewed-by: Kees Cook keescook@chromium.org Message-ID: 286def78955e04382b227cb3e4b6ba272a7442e3.1709850515.git.christophe.leroy@csgroup.eu Signed-off-by: Alexei Starovoitov ast@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org Fixes: 85782e037f8a ("bpf: undo prog rejection on read-only lock failure") Signed-off-by: Tengda Wu wutengda2@huawei.com --- include/linux/filter.h | 5 +++-- kernel/bpf/core.c | 4 +++- kernel/bpf/verifier.c | 8 ++++++-- 3 files changed, 12 insertions(+), 5 deletions(-)

diff --git a/include/linux/filter.h b/include/linux/filter.h index 26487fa86cb8..20b777ef5531 100644 --- a/include/linux/filter.h +++ b/include/linux/filter.h @@ -842,14 +842,15 @@ bpf_ctx_narrow_access_offset(u32 off, u32 size, u32 size_default)

#define bpf_classic_proglen(fprog) (fprog->len * sizeof(fprog->filter[0]))

-static inline void bpf_prog_lock_ro(struct bpf_prog *fp) +static inline int __must_check bpf_prog_lock_ro(struct bpf_prog *fp) { #ifndef CONFIG_BPF_JIT_ALWAYS_ON if (!fp->jited) { set_vm_flush_reset_perms(fp); - set_memory_ro((unsigned long)fp, fp->pages); + return set_memory_ro((unsigned long)fp, fp->pages); } #endif + return 0; }

static inline void bpf_jit_binary_lock_ro(struct bpf_binary_header *hdr) diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c index a722f41e4f4a..d568244f5ae8 100644 --- a/kernel/bpf/core.c +++ b/kernel/bpf/core.c @@ -2375,7 +2375,9 @@ struct bpf_prog *bpf_prog_select_runtime(struct bpf_prog *fp, int *err) }

finalize: - bpf_prog_lock_ro(fp); + *err = bpf_prog_lock_ro(fp); + if (*err) + return fp;

/* The tail call compatibility check can only be done at * this late stage as we need to determine, if we deal diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 08a33b2a2021..e02ed203e90b 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -18627,10 +18627,14 @@ static int jit_subprogs(struct bpf_verifier_env *env) * bpf_prog_load will add the kallsyms for the main program. */ for (i = 1; i < env->subprog_cnt; i++) { - bpf_prog_lock_ro(func[i]); - bpf_prog_kallsyms_add(func[i]); + err = bpf_prog_lock_ro(func[i]); + if (err) + goto out_free; }

+ for (i = 1; i < env->subprog_cnt; i++) + bpf_prog_kallsyms_add(func[i]); + /* Last step: make now unused interpreter insns from main * prog consistent for later dump requests, so they can * later look the same as if they were interpreted only.