Messages in this thread | | | From | KOSAKI Motohiro <> | Subject | Re: [RFC PATCH v3] core_pattern: fix long parameters was truncated by core_pattern handler | Date | Tue, 24 Aug 2010 08:02:22 +0900 (JST) |
| |
> On Fri, Aug 20, 2010 at 05:35:58PM +0800, Xiaotian Feng wrote: > > We met a parameter truncated issue, consider following: > > > echo "|/root/core_pattern_pipe_test %p /usr/libexec/blah-blah-blah \ > > %s %c %p %u %g 11 12345678901234567890123456789012345678 %t" > \ > > /proc/sys/kernel/core_pattern > > > > This is okay because the strings is less than CORENAME_MAX_SIZE. > > "cat /proc/sys/kernel/core_pattern" shows the whole string. but > > after we run core_pattern_pipe_test in man page, we found last > > parameter was truncated like below: > > argc[10]=<12807486> > > > > The root cause is core_pattern allows % specifiers, which need to be > > replaced during parse time, but the replace may expand the strings > > to larger than CORENAME_MAX_SIZE. So if the last parameter is % > > specifiers, the replace code is using snprintf(out_ptr, out_end - out_ptr, ...), > > this will write out of corename array. > > > > Changes since v2: > > Introduced generic function cn_printf and make format_corename remember the time > > has been expanded. > > > > Changes since v1: > > This patch allocates corename at runtime, if the replace doesn't have enough > > memory, expand the corename dynamically. > > > > Signed-off-by: Xiaotian Feng <dfeng@redhat.com> > > Cc: Alexander Viro <viro@zeniv.linux.org.uk> > > Cc: Andrew Morton <akpm@linux-foundation.org> > > Cc: Oleg Nesterov <oleg@redhat.com> > > Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> > > Cc: Neil Horman <nhorman@tuxdriver.com> > > Cc: Roland McGrath <roland@redhat.com> > > --- > > fs/exec.c | 180 ++++++++++++++++++++++++++++++++++++++++-------------------- > > 1 files changed, 120 insertions(+), 60 deletions(-) > > > This looks alot cleaner. Thanks! > Reviewed-by: Neil Horman <nhorman@tuxdriver.com> >
Unfortunatelly, I have no time to review deeply this one. but I see my test works. Also, I'd like to say I like this one.
Thanks.
| |