dc: fix crashes with : operator (thanks istvan bak)
dc crashes because a Blk* sometimes ends getting double freed. To make it crash, any of these lines will do: (each line is a separate input to dc): 1 sa 2 :a le d sa v :a 1 sa 2 :a le d sa :a 1 sa 2 :a le d sa c Fix by assigning p to sptr->val before EMTPY causes a jump. Additionally, dcgetwd() can return 0. all other uses check for 0 ptr; Also fix a buffer overflow.
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03f209427b
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ad9b1234c3
1 changed files with 8 additions and 4 deletions
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@ -638,8 +638,11 @@ commnds(void)
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p = sptr->val;
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if(c >= ARRAYST) {
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rewind(p);
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while(sfeof(p) == 0)
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release(dcgetwd(p));
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while(sfeof(p) == 0) {
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q = dcgetwd(p);
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if(q != 0)
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release(q);
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}
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}
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release(p);
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} else {
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@ -711,6 +714,7 @@ commnds(void)
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p = q;
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}
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}
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sptr->val = p;
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seekc(p,c*PTRSZ);
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q = lookwd(p);
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if(q!=0)
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@ -718,7 +722,6 @@ commnds(void)
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s = pop();
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EMPTY;
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salterwd(p, s);
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sptr->val = p;
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continue;
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case ';':
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p = pop();
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@ -1921,7 +1924,8 @@ command(void)
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sl = line;
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*sl++ = c;
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while((c = readc()) != '\n')
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*sl++ = c;
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if(sl-line < sizeof(line)-1)
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*sl++ = c;
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*sl = 0;
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if((pid = fork()) == 0) {
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execl("/bin/rc","rc","-c",line,nil);
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