Hi Mike,
thanks again. I wonder why it did not reproduce for me earlier.
Could you try attached patch and report back?
Thanks, Adam
On Sun Jun 13, 2021 at 17:16:36 +0100, Mike Crowe wrote:
> Hi Adam,
>
> Thanks for the speedy response.
>
> On Sunday 13 June 2021 at 17:25:20 +0200, Adam Lackorzynski wrote:
> > Hi,
> >
> > thanks for the report. The issue has always been there and had to do
> > with the width of minicom's window (over 256 columns). I have addressed
> > this.
>
> Aha. I switched font at a similar time to upgrading to Bullseye and hadn't
> realised that this meant that my window was no so wide!
>
> > Martin, I have pushed this on the 2.8.x branch (8deebed). Please
> > pick both changes there for the next upload.
>
> I tried compiling master (f118eb9efe89672e5c2a75b34960813db493b2ed) with
> your fix and -fsanitize=address. It looks like the original problem no
> longer occurs, but now when I follow the original steps I get:
>
> =================================================================
> ==56567==ERROR: AddressSanitizer: global-buffer-overflow on address
> 0x557fff340c20 at pc 0x557fff2f550b bp 0x7ffe7d9321e0 sp 0x7ffe7d9321d8
> READ of size 4 at 0x557fff340c20 thread T0
> #0 0x557fff2f550a in mc_wdrawelm_var ../../src/window.c:1059
> #1 0x557fff2d45dc in find_next ../../src/minicom.c:338
> #2 0x557fff2d04c1 in scrollback ../../src/minicom.c:540
> #3 0x557fff2d04c1 in main ../../src/minicom.c:1707
> #4 0x7f88fb12cd09 in __libc_start_main ../csu/libc-start.c:308
> #5 0x557fff2d3059 in _start
> (/overflow/mac/nobackup/git/minicom/build/src/minicom+0x25059)
>
> 0x557fff340c20 is located 32 bytes to the left of global variable
> 'iconv_enabled' defined in '../../src/minicom.c:937:12' (0x557fff340c40) of
> size 4
> 0x557fff340c20 is located 0 bytes to the right of global variable
> 'outofrange' defined in '../../src/minicom.c:177:14' (0x557fff340420) of size
> 2048
> SUMMARY: AddressSanitizer: global-buffer-overflow ../../src/window.c:1059 in
> mc_wdrawelm_var
> Shadow bytes around the buggy address:
> 0x0ab07fe60130: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> 0x0ab07fe60140: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> 0x0ab07fe60150: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> 0x0ab07fe60160: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> 0x0ab07fe60170: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> =>0x0ab07fe60180: 00 00 00 00[f9]f9 f9 f9 04 f9 f9 f9 f9 f9 f9 f9
> 0x0ab07fe60190: 00 f9 f9 f9 f9 f9 f9 f9 04 f9 f9 f9 f9 f9 f9 f9
> 0x0ab07fe601a0: 04 f9 f9 f9 f9 f9 f9 f9 04 f9 f9 f9 f9 f9 f9 f9
> 0x0ab07fe601b0: 04 f9 f9 f9 f9 f9 f9 f9 04 f9 f9 f9 f9 f9 f9 f9
> 0x0ab07fe601c0: 04 f9 f9 f9 f9 f9 f9 f9 04 f9 f9 f9 f9 f9 f9 f9
> 0x0ab07fe601d0: 04 f9 f9 f9 f9 f9 f9 f9 04 f9 f9 f9 f9 f9 f9 f9
> Shadow byte legend (one shadow byte represents 8 application bytes):
> Addressable: 00
> Partially addressable: 01 02 03 04 05 06 07
> Heap left redzone: fa
> Freed heap region: fd
> Stack left redzone: f1
> Stack mid redzone: f2
> Stack right redzone: f3
> Stack after return: f5
> Stack use after scope: f8
> Global redzone: f9
> Global init order: f6
> Poisoned by user: f7
> Container overflow: fc
> Array cookie: ac
> Intra object redzone: bb
> ASan internal: fe
> Left alloca redzone: ca
> Right alloca redzone: cb
> Shadow gap: cc
> ==56567==ABORTING
>
> I hope this is meaningful to you. If not, I'll see if I can work out
> anything more.
>
> Thanks.
>
> Mike.
Adam
--
Adam a...@os.inf.tu-dresden.de
Lackorzynski http://os.inf.tu-dresden.de/~adam/
From b6043854f1e762801347ed4bf4d368b49ad99217 Mon Sep 17 00:00:00 2001
From: Adam Lackorzynski <a...@l4re.org>
Date: Sun, 13 Jun 2021 21:10:59 +0200
Subject: [PATCH] Make mc_getline immune to MAXCOLS
---
src/minicom.c | 20 +++++++++++++-------
1 file changed, 13 insertions(+), 7 deletions(-)
diff --git a/src/minicom.c b/src/minicom.c
index 2719f8c..06dd7be 100644
--- a/src/minicom.c
+++ b/src/minicom.c
@@ -174,7 +174,6 @@ static void shjump(int sig)
static ELM *mc_getline(WIN *w, int no)
{
int i;
- static ELM outofrange[MAXCOLS] = {{0,0,0}};
if (no < us->histlines) {
/* Get a line from the history buffer. */
@@ -189,13 +188,20 @@ static ELM *mc_getline(WIN *w, int no)
/* Get a line from the "us" window. */
no -= us->histlines;
if (no >= w->ys) {
- if (outofrange[0].value == 0) {
- for (i = 0; i < MAXCOLS; i++) {
- outofrange[i].value = ' ';
- outofrange[i].color = us->color;
- outofrange[i].attr = us->attr;
+ static int alloced_columns;
+ static ELM *outofrange;
+ int cols = w->x2 + 1;
+ if (cols > alloced_columns) {
+ free(outofrange);
+ outofrange = malloc(sizeof(*outofrange) * cols);
+ assert(outofrange);
+ alloced_columns = cols;
+
+ for (i = 0; i < cols; i++) {
+ outofrange[i].value = i == 0 ? '~' : ' ';
+ outofrange[i].color = us->color;
+ outofrange[i].attr = us->attr;
}
- outofrange[0].value = '~';
}
return outofrange;
}
--
2.32.0.rc0
