diff options
| author | Alan Modra <amodra@gmail.com> | 2021-05-10 09:56:43 +0930 |
|---|---|---|
| committer | Alan Modra <amodra@gmail.com> | 2021-05-10 10:03:00 +0930 |
| commit | 2d4b49864eba70606b1bee3d0a3e8414189dcd6d (patch) | |
| tree | f3a8c3cd72a12ea0b3181a388beea89de5ac7448 /binutils | |
| parent | 400f0c9b88c68784f9c516422f293bc4d19d9e5b (diff) | |
Avoid possible pointer wrap
PTR supplied to these macros can be read from user input, END is an
end of buffer pointer. It's safer to do arithmetic on END than on PTR.
* dwarf.c (SAFE_BYTE_GET): Check bounds by subtracting amount from
END rather than adding amount to PTR.
(SAFE_SIGNED_BYTE_GET, SAFE_BYTE_GET64): Likewise.
Diffstat (limited to 'binutils')
| -rw-r--r-- | binutils/ChangeLog | 6 | ||||
| -rw-r--r-- | binutils/dwarf.c | 6 |
2 files changed, 9 insertions, 3 deletions
diff --git a/binutils/ChangeLog b/binutils/ChangeLog index 302629794c..ae27252e98 100644 --- a/binutils/ChangeLog +++ b/binutils/ChangeLog @@ -1,3 +1,9 @@ +2021-05-10 Alan Modra <amodra@gmail.com> + + * dwarf.c (SAFE_BYTE_GET): Check bounds by subtracting amount from + END rather than adding amount to PTR. + (SAFE_SIGNED_BYTE_GET, SAFE_BYTE_GET64): Likewise. + 2021-05-09 Alan Modra <amodra@gmail.com> * objcopy.c (eq_string): Delete. diff --git a/binutils/dwarf.c b/binutils/dwarf.c index d93d923968..c584f5b2a2 100644 --- a/binutils/dwarf.c +++ b/binutils/dwarf.c @@ -406,7 +406,7 @@ read_leb128 (unsigned char *data, amount, (int) sizeof (VAL)); \ amount = sizeof (VAL); \ } \ - if (((PTR) + amount) >= (END)) \ + if ((PTR) >= (END) - amount) \ { \ if ((PTR) < (END)) \ amount = (END) - (PTR); \ @@ -434,7 +434,7 @@ read_leb128 (unsigned char *data, do \ { \ unsigned int amount = (AMOUNT); \ - if (((PTR) + amount) >= (END)) \ + if ((PTR) >= (END) - amount) \ { \ if ((PTR) < (END)) \ amount = (END) - (PTR); \ @@ -460,7 +460,7 @@ read_leb128 (unsigned char *data, #define SAFE_BYTE_GET64(PTR, HIGH, LOW, END) \ do \ { \ - if (((PTR) + 8) <= (END)) \ + if ((PTR) <= (END) - 8) \ { \ byte_get_64 ((PTR), (HIGH), (LOW)); \ } \ |