core_pattern: fix truncation by core_pattern handler with long parameters

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.

[[email protected]: coding-style fixes]
Signed-off-by: Xiaotian Feng <[email protected]>
Cc: Alexander Viro <[email protected]>
Cc: Oleg Nesterov <[email protected]>
Cc: KOSAKI Motohiro <[email protected]>
Reviewed-by: Neil Horman <[email protected]>
Cc: Roland McGrath <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

0 files changed, 0 insertions, 0 deletions