Commit 86b84066 authored by David S. Miller's avatar David S. Miller
Browse files

Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf 



Daniel Borkmann says:

====================
pull-request: bpf 2021-06-02

The following pull-request contains BPF updates for your *net* tree.

We've added 2 non-merge commits during the last 7 day(s) which contain
a total of 4 files changed, 19 insertions(+), 24 deletions(-).

The main changes are:

1) Fix pahole BTF generation when ccache is used, from Javier Martinez Canillas.

2) Fix BPF lockdown hooks in bpf_probe_read_kernel{,_str}() helpers which caused
   a deadlock from bcc programs, triggered OOM killer from audit side and didn't
   work generally with SELinux policy rules due to pointing to wrong task struct,
   from Daniel Borkmann.
====================

Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parents c47cc304 ff40e510

kernel/bpf/helpers.c

+5 −2
Original line number Diff line number Diff line
@@ -14,6 +14,7 @@ 
#include <linux/jiffies.h>

#include <linux/pid_namespace.h>

#include <linux/proc_ns.h>

#include <linux/security.h>



#include "../../lib/kstrtox.h"
@@ -1069,11 +1070,13 @@ bpf_base_func_proto(enum bpf_func_id func_id) 
	case BPF_FUNC_probe_read_user:

		return &bpf_probe_read_user_proto;

	case BPF_FUNC_probe_read_kernel:

		return &bpf_probe_read_kernel_proto;

		return security_locked_down(LOCKDOWN_BPF_READ) < 0 ?

		       NULL : &bpf_probe_read_kernel_proto;

	case BPF_FUNC_probe_read_user_str:

		return &bpf_probe_read_user_str_proto;

	case BPF_FUNC_probe_read_kernel_str:

		return &bpf_probe_read_kernel_str_proto;

		return security_locked_down(LOCKDOWN_BPF_READ) < 0 ?

		       NULL : &bpf_probe_read_kernel_str_proto;

	case BPF_FUNC_snprintf_btf:

		return &bpf_snprintf_btf_proto;

	case BPF_FUNC_snprintf:

kernel/trace/bpf_trace.c

+12 −20
Original line number Diff line number Diff line
@@ -215,15 +215,10 @@ const struct bpf_func_proto bpf_probe_read_user_str_proto = { 
static __always_inline int

bpf_probe_read_kernel_common(void *dst, u32 size, const void *unsafe_ptr)

{

	int ret = security_locked_down(LOCKDOWN_BPF_READ);

	int ret;



	if (unlikely(ret < 0))

		goto fail;

	ret = copy_from_kernel_nofault(dst, unsafe_ptr, size);

	if (unlikely(ret < 0))

		goto fail;

	return ret;

fail:

		memset(dst, 0, size);

	return ret;

}
@@ -246,10 +241,7 @@ const struct bpf_func_proto bpf_probe_read_kernel_proto = { 
static __always_inline int

bpf_probe_read_kernel_str_common(void *dst, u32 size, const void *unsafe_ptr)

{

	int ret = security_locked_down(LOCKDOWN_BPF_READ);



	if (unlikely(ret < 0))

		goto fail;

	int ret;



	/*

	 * The strncpy_from_kernel_nofault() call will likely not fill the
@@ -262,10 +254,6 @@ bpf_probe_read_kernel_str_common(void *dst, u32 size, const void *unsafe_ptr) 
	 */

	ret = strncpy_from_kernel_nofault(dst, unsafe_ptr, size);

	if (unlikely(ret < 0))

		goto fail;



	return ret;

fail:

		memset(dst, 0, size);

	return ret;

}
@@ -1011,16 +999,20 @@ bpf_tracing_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 
	case BPF_FUNC_probe_read_user:

		return &bpf_probe_read_user_proto;

	case BPF_FUNC_probe_read_kernel:

		return &bpf_probe_read_kernel_proto;

		return security_locked_down(LOCKDOWN_BPF_READ) < 0 ?

		       NULL : &bpf_probe_read_kernel_proto;

	case BPF_FUNC_probe_read_user_str:

		return &bpf_probe_read_user_str_proto;

	case BPF_FUNC_probe_read_kernel_str:

		return &bpf_probe_read_kernel_str_proto;

		return security_locked_down(LOCKDOWN_BPF_READ) < 0 ?

		       NULL : &bpf_probe_read_kernel_str_proto;

#ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE

	case BPF_FUNC_probe_read:

		return &bpf_probe_read_compat_proto;

		return security_locked_down(LOCKDOWN_BPF_READ) < 0 ?

		       NULL : &bpf_probe_read_compat_proto;

	case BPF_FUNC_probe_read_str:

		return &bpf_probe_read_compat_str_proto;

		return security_locked_down(LOCKDOWN_BPF_READ) < 0 ?

		       NULL : &bpf_probe_read_compat_str_proto;

#endif

#ifdef CONFIG_CGROUPS

	case BPF_FUNC_get_current_cgroup_id:

scripts/Makefile.modfinal

+1 −1
Original line number Diff line number Diff line
@@ -59,7 +59,7 @@ quiet_cmd_ld_ko_o = LD [M] $@ 
quiet_cmd_btf_ko = BTF [M] $@

      cmd_btf_ko = 							\

	if [ -f vmlinux ]; then						\

		LLVM_OBJCOPY=$(OBJCOPY) $(PAHOLE) -J --btf_base vmlinux $@; \

		LLVM_OBJCOPY="$(OBJCOPY)" $(PAHOLE) -J --btf_base vmlinux $@; \

	else								\

		printf "Skipping BTF generation for %s due to unavailability of vmlinux\n" $@ 1>&2; \

	fi;

scripts/link-vmlinux.sh

+1 −1
Original line number Diff line number Diff line
@@ -240,7 +240,7 @@ gen_btf() 
	fi



	info "BTF" ${2}

	LLVM_OBJCOPY=${OBJCOPY} ${PAHOLE} -J ${extra_paholeopt} ${1}

	LLVM_OBJCOPY="${OBJCOPY}" ${PAHOLE} -J ${extra_paholeopt} ${1}



	# Create ${2} which contains just .BTF section but no symbols. Add

	# SHF_ALLOC because .BTF will be part of the vmlinux image. --strip-all