2010-07-23 07:04:31

by Stephen Boyd

Subject: [PATCH] nconfig: Fix segfault when help contains special characters

nconfig segfaults when help text contains the character '%'. For a quick
example, navigate to the kernel compression options and get the help for
bzip2. Doing so triggers a call to mvwprintw() with a string containing
'%' and no extra arguments to fill in the specifier's value. Fix this
case by printing the literal string retrieved from the kconfig.

#0 0x00002b52b6b11d83 in vfprintf () from /lib/libc.so.6
#1 0x00002b52b6bad010 in __vsnprintf_chk () from /lib/libc.so.6
#2 0x00002b52b623991b in _nc_printf_string () from
/lib/libncursesw.so.5
#3 0x00002b52b6234cff in vwprintw () from /lib/libncursesw.so.5
#4 0x00002b52b6234db9 in mvwprintw () from /lib/libncursesw.so.5
#5 0x00000000004151d8 in fill_window (win=0x21b64c0,
text=0x21b62b0 "CONFIG_KERNEL_BZIP2:\n\nIts compression ratio and
speed is intermediate.\nDecompression speed is slowest among the
three. The kernel\nsize is about 10% smaller with bzip2, in
comparison to gzip.\nBzip2 us"...)
at scripts/kconfig/nconf.gui.c:229
#6 0x0000000000416335 in show_scroll_win (main_window=0x21a5630,
title=0x157fa30 "Bzip2",
text=0x21b62b0 "CONFIG_KERNEL_BZIP2:\n\nIts compression
ratio and speed is intermediate.\nDecompression speed is
slowest among the three. The kernel\nsize is about 10%
smaller with bzip2, in comparison to gzip.\nBzip2 us"...)
at scripts/kconfig/nconf.gui.c:535
#7 0x00000000004055b2 in show_help (menu=0x157f9d0)
at scripts/kconfig/nconf.c:1257
#8 0x0000000000405897 in conf_choice (menu=0x157f130)
at scripts/kconfig/nconf.c:1321
#9 0x0000000000405326 in conf (menu=0x157d130) at
scripts/kconfig/nconf.c:1208
#10 0x00000000004052e8 in conf (menu=0xb434a0) at
scripts/kconfig/nconf.c:1203
#11 0x0000000000406092 in main (ac=2, av=0x7fff96a93c38)

Cc: Michal Marek <[email protected]>
Cc: Nir Tzachar <[email protected]>
Signed-off-by: Stephen Boyd <[email protected]>
---
scripts/kconfig/nconf.gui.c | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/scripts/kconfig/nconf.gui.c b/scripts/kconfig/nconf.gui.c
index 115edb4..a9d9344 100644
--- a/scripts/kconfig/nconf.gui.c
+++ b/scripts/kconfig/nconf.gui.c
@@ -226,7 +226,7 @@ void fill_window(WINDOW *win, const char *text)
int len = get_line_length(line);
strncpy(tmp, line, min(len, x));
tmp[len] = '\0';
- mvwprintw(win, i, 0, tmp);
+ mvwprintw(win, i, 0, "%s", tmp);
}
}

--
1.7.2.rc3.57.g77b5b

2010-07-23 09:26:00

by Michal Marek

Subject: Re: [PATCH] nconfig: Fix segfault when help contains special characters

On 23.7.2010 09:04, Stephen Boyd wrote:
> nconfig segfaults when help text contains the character '%'. For a quick
> example, navigate to the kernel compression options and get the help for
> bzip2. Doing so triggers a call to mvwprintw() with a string containing
> '%' and no extra arguments to fill in the specifier's value. Fix this
> case by printing the literal string retrieved from the kconfig.

Thanks, applied.

Michal

2010-07-25 08:30:17

by Nir Tzachar

Subject: Re: [PATCH] nconfig: Fix segfault when help contains special characters

2010/7/23 Michal Marek <[email protected]>:
> On 23.7.2010 09:04, Stephen Boyd wrote:
>> nconfig segfaults when help text contains the character '%'. For a quick
>> example, navigate to the kernel compression options and get the help for
>> bzip2. Doing so triggers a call to mvwprintw() with a string containing
>> '%' and no extra arguments to fill in the specifier's value. Fix this
>> case by printing the literal string retrieved from the kconfig.
>
> Thanks, applied.
>
> Michal


Thanks. It is also nice to see people are using nconfig.

Cheers.