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* [PATCH iproute2 -master] tc, bpf: make sure relo is in relation with map section
@ 2016-01-21 23:46 Daniel Borkmann
  2016-01-22  3:13 ` Alexei Starovoitov
  2016-02-02  5:06 ` Stephen Hemminger
  0 siblings, 2 replies; 3+ messages in thread
From: Daniel Borkmann @ 2016-01-21 23:46 UTC (permalink / raw)
  To: stephen; +Cc: netdev, alexei.starovoitov, Daniel Borkmann

Add a test that symbol from relocation entry is actually related
to map section and bail out with an error message if it's not the
case; in relation to [1].

  [1] https://llvm.org/bugs/show_bug.cgi?id=26243

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
---
 tc/tc_bpf.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/tc/tc_bpf.c b/tc/tc_bpf.c
index 219ffa5..3c97cdb 100644
--- a/tc/tc_bpf.c
+++ b/tc/tc_bpf.c
@@ -1336,6 +1336,12 @@ static int bpf_apply_relo_data(struct bpf_elf_ctx *ctx,
 
 		if (gelf_getsym(ctx->sym_tab, GELF_R_SYM(relo.r_info), &sym) != &sym)
 			return -EIO;
+		if (sym.st_shndx != ctx->sec_maps) {
+			fprintf(stderr, "ELF contains non-map related relo data in "
+				"entry %u pointing to section %u! Compiler bug?!\n",
+				relo_ent, sym.st_shndx);
+			return -EIO;
+		}
 
 		rmap = sym.st_value / sizeof(struct bpf_elf_map);
 		if (rmap >= ARRAY_SIZE(ctx->map_fds))
-- 
1.9.3

^ permalink raw reply related	[flat|nested] 3+ messages in thread

* Re: [PATCH iproute2 -master] tc, bpf: make sure relo is in relation with map section
  2016-01-21 23:46 [PATCH iproute2 -master] tc, bpf: make sure relo is in relation with map section Daniel Borkmann
@ 2016-01-22  3:13 ` Alexei Starovoitov
  2016-02-02  5:06 ` Stephen Hemminger
  1 sibling, 0 replies; 3+ messages in thread
From: Alexei Starovoitov @ 2016-01-22  3:13 UTC (permalink / raw)
  To: Daniel Borkmann; +Cc: stephen, netdev, wangnan0

On Fri, Jan 22, 2016 at 12:46:28AM +0100, Daniel Borkmann wrote:
> Add a test that symbol from relocation entry is actually related
> to map section and bail out with an error message if it's not the
> case; in relation to [1].
> 
>   [1] https://llvm.org/bugs/show_bug.cgi?id=26243
> 
> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

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

Thanks. Useful check.
Wang, we probably want something like this in libbpf as well.

> ---
>  tc/tc_bpf.c | 6 ++++++
>  1 file changed, 6 insertions(+)
> 
> diff --git a/tc/tc_bpf.c b/tc/tc_bpf.c
> index 219ffa5..3c97cdb 100644
> --- a/tc/tc_bpf.c
> +++ b/tc/tc_bpf.c
> @@ -1336,6 +1336,12 @@ static int bpf_apply_relo_data(struct bpf_elf_ctx *ctx,
>  
>  		if (gelf_getsym(ctx->sym_tab, GELF_R_SYM(relo.r_info), &sym) != &sym)
>  			return -EIO;
> +		if (sym.st_shndx != ctx->sec_maps) {
> +			fprintf(stderr, "ELF contains non-map related relo data in "
> +				"entry %u pointing to section %u! Compiler bug?!\n",
> +				relo_ent, sym.st_shndx);
> +			return -EIO;
> +		}
>  
>  		rmap = sym.st_value / sizeof(struct bpf_elf_map);
>  		if (rmap >= ARRAY_SIZE(ctx->map_fds))
> -- 
> 1.9.3
> 

^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: [PATCH iproute2 -master] tc, bpf: make sure relo is in relation with map section
  2016-01-21 23:46 [PATCH iproute2 -master] tc, bpf: make sure relo is in relation with map section Daniel Borkmann
  2016-01-22  3:13 ` Alexei Starovoitov
@ 2016-02-02  5:06 ` Stephen Hemminger
  1 sibling, 0 replies; 3+ messages in thread
From: Stephen Hemminger @ 2016-02-02  5:06 UTC (permalink / raw)
  To: Daniel Borkmann; +Cc: netdev, alexei.starovoitov

On Fri, 22 Jan 2016 00:46:28 +0100
Daniel Borkmann <daniel@iogearbox.net> wrote:

> Add a test that symbol from relocation entry is actually related
> to map section and bail out with an error message if it's not the
> case; in relation to [1].
> 
>   [1] https://llvm.org/bugs/show_bug.cgi?id=26243
> 
> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
> ---

Applied

^ permalink raw reply	[flat|nested] 3+ messages in thread

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2016-01-21 23:46 [PATCH iproute2 -master] tc, bpf: make sure relo is in relation with map section Daniel Borkmann
2016-01-22  3:13 ` Alexei Starovoitov
2016-02-02  5:06 ` Stephen Hemminger

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