Set upper limit for REP escape sequence argument

Previously, printf 'L\033[2147483647b' would call tputc('L') 2^31 times,
making st unresponsive. This commit allows repeating the last character
at most 65535 times in order to prevent freezing and DoS attacks.

ref.
https://git.suckless.org/st/commit/95f22c53059ccd60ee701ccf2659dacd95e4e89a.html
This commit is contained in:
Bakkeby 2024-03-07 21:44:39 +01:00
parent 400aa4492f
commit b7add20215

2
st.c
View File

@ -2254,7 +2254,7 @@ csihandle(void)
ttywrite(vtiden, strlen(vtiden), 0);
break;
case 'b': /* REP -- if last char is printable print it <n> more times */
DEFAULT(csiescseq.arg[0], 1);
LIMIT(csiescseq.arg[0], 1, 65535);
if (term.lastc)
while (csiescseq.arg[0]-- > 0)
tputc(term.lastc);