Merge branch 'bpf-fixes'

Daniel Borkmann says:

====================
First one is a panic I ran into while testing the second
one where we got several syzkaller reports. Series here
fixes both.

Thanks!
====================

Signed-off-by: Alexei Starovoitov <ast@kernel.org>

1 files changed, 41 insertions, 22 deletions

diff --git a/include/linux/filter.h b/include/linux/filter.h
index 45fc0f5000d8..108f9812e196 100644
--- a/include/linux/filter.h
+++ b/include/linux/filter.h
@@ -469,7 +469,8 @@ struct sock_fprog_kern {
 };
 
 struct bpf_binary_header {
-	unsigned int pages;
+	u16 pages;
+	u16 locked:1;
 	u8 image[];
 };
 
@@ -671,15 +672,18 @@ bpf_ctx_narrow_access_ok(u32 off, u32 size, u32 size_default)
 
 #define bpf_classic_proglen(fprog) (fprog->len * sizeof(fprog->filter[0]))
 
-#ifdef CONFIG_ARCH_HAS_SET_MEMORY
 static inline void bpf_prog_lock_ro(struct bpf_prog *fp)
 {
+#ifdef CONFIG_ARCH_HAS_SET_MEMORY
 	fp->locked = 1;
-	WARN_ON_ONCE(set_memory_ro((unsigned long)fp, fp->pages));
+	if (set_memory_ro((unsigned long)fp, fp->pages))
+		fp->locked = 0;
+#endif
 }
 
 static inline void bpf_prog_unlock_ro(struct bpf_prog *fp)
 {
+#ifdef CONFIG_ARCH_HAS_SET_MEMORY
 	if (fp->locked) {
 		WARN_ON_ONCE(set_memory_rw((unsigned long)fp, fp->pages));
 		/* In case set_memory_rw() fails, we want to be the first
@@ -687,34 +691,30 @@ static inline void bpf_prog_unlock_ro(struct bpf_prog *fp)
 		 */
 		fp->locked = 0;
 	}
+#endif
 }
 
 static inline void bpf_jit_binary_lock_ro(struct bpf_binary_header *hdr)
 {
-	WARN_ON_ONCE(set_memory_ro((unsigned long)hdr, hdr->pages));
-}
-
-static inline void bpf_jit_binary_unlock_ro(struct bpf_binary_header *hdr)
-{
-	WARN_ON_ONCE(set_memory_rw((unsigned long)hdr, hdr->pages));
-}
-#else
-static inline void bpf_prog_lock_ro(struct bpf_prog *fp)
-{
-}
-
-static inline void bpf_prog_unlock_ro(struct bpf_prog *fp)
-{
-}
-
-static inline void bpf_jit_binary_lock_ro(struct bpf_binary_header *hdr)
-{
+#ifdef CONFIG_ARCH_HAS_SET_MEMORY
+	hdr->locked = 1;
+	if (set_memory_ro((unsigned long)hdr, hdr->pages))
+		hdr->locked = 0;
+#endif
 }
 
 static inline void bpf_jit_binary_unlock_ro(struct bpf_binary_header *hdr)
 {
+#ifdef CONFIG_ARCH_HAS_SET_MEMORY
+	if (hdr->locked) {
+		WARN_ON_ONCE(set_memory_rw((unsigned long)hdr, hdr->pages));
+		/* In case set_memory_rw() fails, we want to be the first
+		 * to crash here instead of some random place later on.
+		 */
+		hdr->locked = 0;
+	}
+#endif
 }
-#endif /* CONFIG_ARCH_HAS_SET_MEMORY */
 
 static inline struct bpf_binary_header *
 bpf_jit_binary_hdr(const struct bpf_prog *fp)
@@ -725,6 +725,22 @@ bpf_jit_binary_hdr(const struct bpf_prog *fp)
 	return (void *)addr;
 }
 
+#ifdef CONFIG_ARCH_HAS_SET_MEMORY
+static inline int bpf_prog_check_pages_ro_single(const struct bpf_prog *fp)
+{
+	if (!fp->locked)
+		return -ENOLCK;
+	if (fp->jited) {
+		const struct bpf_binary_header *hdr = bpf_jit_binary_hdr(fp);
+
+		if (!hdr->locked)
+			return -ENOLCK;
+	}
+
+	return 0;
+}
+#endif
+
 int sk_filter_trim_cap(struct sock *sk, struct sk_buff *skb, unsigned int cap);
 static inline int sk_filter(struct sock *sk, struct sk_buff *skb)
 {
@@ -961,6 +977,9 @@ static inline void bpf_prog_kallsyms_del(struct bpf_prog *fp)
 }
 #endif /* CONFIG_BPF_JIT */
 
+void bpf_prog_kallsyms_del_subprogs(struct bpf_prog *fp);
+void bpf_prog_kallsyms_del_all(struct bpf_prog *fp);
+
 #define BPF_ANC		BIT(15)
 
 static inline bool bpf_needs_clear_a(const struct sock_filter *first)