[PATCH] Kcore elf note namesz field fix

[PATCH] Kcore elf note namesz field fix

[Vivek Goyal]

o As per ELF specifications, it looks like that elf note "namesz" field contains
  the length of "name" including the size of null character. And 
  currently we are filling "namesz" without taking into the consideration
  the null character size.

o Kexec-tools performs this check deligently hence I ran into the issue
  while trying to open /proc/kcore in kexec-tools for some info.

Signed-off-by: Vivek Goyal <vgoyal@in.ibm.com>
---

 fs/proc/kcore.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff -puN fs/proc/kcore.c~kcore-elf-note-namesz-fix fs/proc/kcore.c
--- linux-2.6.18-rc3-1M/fs/proc/kcore.c~kcore-elf-note-namesz-fix	2006-08-31 16:10:41.000000000 -0400
+++ linux-2.6.18-rc3-1M-root/fs/proc/kcore.c	2006-08-31 16:10:41.000000000 -0400
@@ -100,7 +100,7 @@ static int notesize(struct memelfnote *e
 	int sz;
 
 	sz = sizeof(struct elf_note);
-	sz += roundup(strlen(en->name), 4);
+	sz += roundup((strlen(en->name) + 1), 4);
 	sz += roundup(en->datasz, 4);
 
 	return sz;
@@ -116,7 +116,7 @@ static char *storenote(struct memelfnote
 
 #define DUMP_WRITE(addr,nr) do { memcpy(bufp,addr,nr); bufp += nr; } while(0)
 
-	en.n_namesz = strlen(men->name);
+	en.n_namesz = strlen(men->name) + 1;
 	en.n_descsz = men->datasz;
 	en.n_type = men->type;
 
_

Re: [PATCH] Kcore elf note namesz field fix

[Horms]

[ This is a repost, I mucked up the headers the first time around ]

On Tue, 5 Sep 2006 15:32:22 -0400, Vivek Goyal wrote:
> 
> 
> 
> o As per ELF specifications, it looks like that elf note "namesz" field contains
>  the length of "name" including the size of null character. And 
>  currently we are filling "namesz" without taking into the consideration
>  the null character size.
> 
> o Kexec-tools performs this check deligently hence I ran into the issue
>  while trying to open /proc/kcore in kexec-tools for some info.
> 
> Signed-off-by: Vivek Goyal <vgoyal@in.ibm.com>

That is in keeping with my reading of pages 2-4 and 2-5
of version 1.1 of the specification (is there a later version?)

Acked: Simon Horman <horms@verge.net.au>

> ---
> 
> fs/proc/kcore.c |    4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff -puN fs/proc/kcore.c~kcore-elf-note-namesz-fix fs/proc/kcore.c
> --- linux-2.6.18-rc3-1M/fs/proc/kcore.c~kcore-elf-note-namesz-fix	2006-08-31 16:10:41.000000000 -0400
> +++ linux-2.6.18-rc3-1M-root/fs/proc/kcore.c	2006-08-31 16:10:41.000000000 -0400
> @@ -100,7 +100,7 @@ static int notesize(struct memelfnote *e
> 	int sz;
> 
> 	sz = sizeof(struct elf_note);
> -	sz += roundup(strlen(en->name), 4);
> +	sz += roundup((strlen(en->name) + 1), 4);
> 	sz += roundup(en->datasz, 4);
> 
> 	return sz;
> @@ -116,7 +116,7 @@ static char *storenote(struct memelfnote
> 
> #define DUMP_WRITE(addr,nr) do { memcpy(bufp,addr,nr); bufp += nr; } while(0)
> 
> -	en.n_namesz = strlen(men->name);
> +	en.n_namesz = strlen(men->name) + 1;
> 	en.n_descsz = men->datasz;
> 	en.n_type = men->type;
> 
> _