From: Christophe Leroy <christophe.leroy@csgroup.eu>
To: Alexei Starovoitov <ast@kernel.org>,
Daniel Borkmann <daniel@iogearbox.net>,
Andrii Nakryiko <andrii@kernel.org>,
Martin KaFai Lau <martin.lau@linux.dev>,
Eduard Zingerman <eddyz87@gmail.com>, Song Liu <song@kernel.org>,
Yonghong Song <yonghong.song@linux.dev>,
John Fastabend <john.fastabend@gmail.com>,
KP Singh <kpsingh@kernel.org>,
Stanislav Fomichev <sdf@google.com>, Hao Luo <haoluo@google.com>,
Jiri Olsa <jolsa@kernel.org>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>,
bpf@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org, loongarch@lists.linux.dev,
linux-mips@vger.kernel.org, linux-parisc@vger.kernel.org,
linux-s390@vger.kernel.org, sparclinux@vger.kernel.org,
netdev@vger.kernel.org,
"linux-hardening @ vger . kernel . org"
<linux-hardening@vger.kernel.org>,
Kees Cook <keescook@chromium.org>
Subject: [PATCH bpf-next v3 1/2] bpf: Take return from set_memory_ro() into account with bpf_prog_lock_ro()
Date: Fri, 8 Mar 2024 06:38:07 +0100 [thread overview]
Message-ID: <286def78955e04382b227cb3e4b6ba272a7442e3.1709850515.git.christophe.leroy@csgroup.eu> (raw)
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>
---
Note: next patch is autonomous, it is sent as a follow-up of this one to minimize risk of conflict on filter.h because the two changes are too close to each other.
v3: Perform bpf_prog_kallsyms_add() after protection of all subprog have succeeded.
v2: No modification (Just added link in patch message), patchwork discarded this series due to failed test of s390 but it seems unrelated, see https://lore.kernel.org/bpf/wvd5gzde5ejc2rzsbrtwqyof56uw5ea3rxntfrxtkdabzcuwt6@w7iczzhmay2i/T/#m2e61446f42d5dc3d78f2e0e8b7a783f15cfb109d
---
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 36cc29a2934c..7dd59bccaeec 100644
--- a/include/linux/filter.h
+++ b/include/linux/filter.h
@@ -884,14 +884,15 @@ 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 9ee4536d0a09..ae28bab2b138 100644
--- a/kernel/bpf/core.c
+++ b/kernel/bpf/core.c
@@ -2393,7 +2393,9 @@ 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 ee86e4d7d5fc..c97108935c9a 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -19153,10 +19153,14 @@ 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.
--
2.43.0
next reply other threads:[~2024-03-08 5:38 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-03-08 5:38 Christophe Leroy [this message]
2024-03-08 5:38 ` [PATCH bpf-next v3 2/2] bpf: Take return from set_memory_rox() into account with bpf_jit_binary_lock_ro() Christophe Leroy
2024-03-15 2:30 ` [PATCH bpf-next v3 1/2] bpf: Take return from set_memory_ro() into account with bpf_prog_lock_ro() patchwork-bot+netdevbpf
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